My scientist friend asked how to detox or clean his body from toxins

Over the years, I have experienced family and friends dying of cancer. I observed their lifestyle and toxins they are exposed to. So to answer my friend’s question on how to detox and the mechanism of cleaning our body or getting rid of toxins, I listed some items for Dos and Donts.

Our lymphatic system which travels opposite our blood is responsible for cleaning our blood.  Search for lymphatic, massage and detox in this site http://www.clubalthea.com

When we clean the many bad foods or toxins that entered our body, we must clean our liver first, our laboratory.  It is closely linked to our heart that during our last breath, our liver is the first and last signal that our heart gets to shut down.

Detox or cleaning our cells from toxins is the key to living longer, the anti-aging process we all are seeking for. In my 50s, I could have died long time ago if I was born centuries ago with no clean water, fresh produce and raising a dozen children. Each child is minus 5 years of a woman’s age.

Detox is like cleaning the toilet. The following are detox tips and anti-aging tips to clean your cells:

Dos in cleansing your body from toxin, also detoxes your liver

  • Massage
  • Adequate sleep
  • Filtered water
  • Lemon
  • Baking soda (pinch in your drinking water)
  • Activated charcoal
  • Digestive enzymes from pineapple and papaya
  • Apple cider vinegar
  • Wash produce with salt or diluted vinegar
  • No over ripe fruits and left over foods or 3-day old rice ( aflatoxin , mycotoxin )
  • No charred BBQ
  • Whole foods ; sulfur rich as they are anti-inflammatory (ginger, garlic, turmeric, coconut, walnuts)
  • Deep breathing thru nose and blow out thru mouth
  • Prayer: May God’s light energy be with you and say Amen to accept it.
  • Resveratrol from Berries, kiwi, citrus fruit
  • Fasting
  • Activated charcoal
  • Clean air

Donts are ways that when practiced or consumed can kills our nerve cells and produce toxins in our cells.

  • Avoidance of too much caffeine, iron and sugar, these are food for cancer
  • Other metal toxins
  • TRANS fat
  • Processed
  • Plastics in food
  • Stress
  • Shift work: not sleeping from 10pm to 4 am
  • Radiation
  • Over medications, chemo, other carcinogens
  • Avoid exposure to fumes, chemicals (formaldehydes,carcinogens,toxins)

 

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Hi Connnie,

And what is your recipe for liver detox and the mechanism by which it works to accomplish that?

From: Male friend in his late 50s whose brother died of pancreatic cancer

p53 , resveratrol , pancreatic cancer and apoptosis

Intrigued by pancreatic cancer, infection and environmental toxins, I stumble into this topic from Wiki. One of my clients died of stomach , esophagal and pancreatic cancer. Previous to that , he had shingles and other infections.  Her immune system became weaker during the last 5 years before his death.  He disregarded stomach pains and takes TUMs regularly and other anti-viral med for his shingles. His autopsy revealed stomach cancer.

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The p53 mechanism functions as a critical signaling pathway in cell growth, which regulates apoptosis, cell cycle arrest, metabolism and other processes 10. In pancreatic cancer, most cells have mutations in p53 protein, causing the loss of apoptotic activity.

The p53 upregulated modulator of apoptosis (PUMA) also known as Bcl-2-binding component 3 (BBC3), is a pro-apoptotic protein, member of the Bcl-2 protein family.[3][4] In humans, the Bcl-2-binding component 3 protein is encoded by the BBC3 gene.[3][4]

The expression of PUMA is regulated by the tumor suppressor p53. PUMA is involved in p53-dependent and -independent apoptosis induced by a variety of signals, and is regulated by transcription factors, not by post-translational modifications. After activation, PUMA interacts with antiapoptotic Bcl-2 family members, thus freeing Bax and/or Bak which are then able to signal apoptosis to the mitochondria. Following mitochondrial dysfunction, the caspase cascade is activated ultimately leading to cell death.[5]

Structure

The PUMA protein is part of the BH3-only subgroup of Bcl-2 family proteins. This group of proteins only share sequence similarity in the BH3 domain, which is required for interactions with Bcl-2-like proteins, such as Bcl-2and Bcl-xL.[3] Structural analysis has shown that PUMA directly binds to antiapoptotic Bcl-2 family proteins via an amphiphatic α-helical structure which is formed by the BH3 domain.[6] The mitochondrial localization of PUMA is dictated by a hydrophobic domain on its C-terminal portion.[7] No posttranslational modification of PUMA has been discovered yet.[5]

Mechanism of action

Biochemical studies have shown that PUMA interacts with antiapoptotic Bcl-2 family members such as Bcl-xLBcl-2Mcl-1Bcl-w, and A1, inhibiting their interaction with the proapoptotic molecules, Bax and Bak. When the inhibition of these is lifted, they result in the translocation of Bax and activation of mitochondrial dysfunctionresulting in release of mitochondrial apoptogenic proteins cytochrome cSMAC, and apoptosis-inducing factor(AIF) leading to caspase activation and cell death.[3]

Because PUMA has high affinity for binding to Bcl-2 family members, another hypothesis is that PUMA directly activates Bax and/or Bak and through Bax multimerization triggers mitochondrial translocation and with it induces apoptosis.[8][9] Various studies have shown though, that PUMA does not rely on direct interaction with Bax/Bak to induce apoptosis.[10][11]

Regulation

Induction

The majority of PUMA induced apoptosis occurs through activation of the tumor suppressor protein p53. p53 is activated by survival signals such as glucose deprivation[12] and increases expression levels of PUMA. This increase in PUMA levels induces apoptosis through mitochondrial dysfunction. p53, and with it PUMA, is activated due to DNA damage caused by a variety of genotoxic agents. Other agents that induce p53 dependent apoptosis are neurotoxins,[13][14] proteasome inhibitors,[15] microtubule poisons,[16] and transcription inhibitors.[17] PUMA apoptosis may also be induced independently of p53 activation by other stimuli, such as oncogenic stress[18][19] growth factor and/or cytokine withdrawal and kinase inhibition,[4][20][21] ER stress, altered redox status,[22][23] ischemia,[8][24] immunemodulation,[25][26] and infection.[5][27]

Degradation

PUMA levels are downregulated through the activation of caspase-3 and a protease inhibited by the serpase inhibitor N-tosyl-L-phenylalanine chloromethyl ketone, in response to signals such as the cytokine TGFβ, the death effector TRAIL or chemical drugs such as anisomycin.[28] PUMA protein is degraded in a proteasome dependent manner and its degradation is regulated by phosphorylation at a conserved serine residue at position 10.[29]

Role in cancer

Several studies have shown that PUMA function is affected or absent in cancer cells. Additionally, many human tumors contain p53 mutations,[30] which results in no induction of PUMA, even after DNA damage induced through irradiation or chemotherapy drugs.[31] Other cancers, which exhibit overexpression of antiapotptic Bcl-2family proteins, counteract and overpower PUMA-induced apoptosis.[32] Even though PUMA function is compromised in most cancer cells, it does not appear that genetic inactivation of PUMA is a direct target of cancer.[33][34][35] Many cancers do exhibit p53 gene mutations, making gene therapies that target this gene [clarification needed] impossible, but an alternate pathway may be to focus on therapeutic to target PUMA and induce apoptosis in cancer cells. Animal studies have shown that PUMA does play a role in tumor suppression, but lack of PUMA activity alone does not translate to spontaneous formation of malignancies.[36][37][38][39][40]Inhibiting PUMA induced apoptosis may be an interesting target for reducing the side effects of cancer treatments, such as chemotherapy, which induce apoptosis in rapidly dividing healthy cells in addition to rapidly dividing cancer cells.[5]

PUMA can also function as an indicator of p53 mutations. Many cancers exhibit mutations in the p53 gene, but this mutation can only be detected through extensive DNA sequencing. Studies have shown that cells with p53 mutations have significantly lower levels of PUMA, making it a good candidate for a protein marker of p53 mutations, providing a simpler method for testing for p53 mutations.[41]

Cancer therapeutics

Therapeutic agents targeting PUMA for cancer patients are emerging. PUMA inducers target cancer or tumor cells, while PUMA inhibitors can be targeted to normal, healthy cells to help alleviate the undesired side effects of chemo and radiation therapy.[5]

Cancer treatments

Research has shown that increased PUMA expression with or without chemotherapy or irradiation is highly toxic to cancer cells, specifically lung,[42] head and neck,[43]esophagus,[44] melanoma,[45] malignant glioma,[46] gastric glands,[47] breast[48] and prostate.[49] In addition, studies have shown that PUMA adenovirus seems to induce apoptosis more so than p53 adenovirus.[42][43][44] This is beneficial in combating cancers that inhibit p53 activation and therefore indirectly decrease PUMA expression levels.[5]

Resveratrol, a plant-derived stilbenoid, is currently under investigation as a cancer treatment. Resveratrol acts to inhibit and decrease expression of antiapoptotic Bcl-2family members while also increasing p53 expression. The combination of these two mechanisms leads to apoptosis via activation of PUMA, Noxa and other proapoptotic proteins, resulting in mitochondrial dysfunction

Novel Type of Cell Death in Huntington’s Disease May Lead to Effective New Therapies

Summary: Researchers have identified a novel type of cell death associated with Huntington’s disease.

Source: Tokyo Medical and Dental University.

Researchers centered at Tokyo Medical and Dental University (TMDU) identify novel type of cell death in Huntington’s disease that may uncover new treatments.

In Huntington’s disease (HD), the huntingtin gene is mutated, causing progressive neuronal death. This leads to defects in movement, behavior, and cognitive ability. Apoptosis, autophagy, and necrosis are the three main types of cell death, but researchers have not yet been able to determine what type of cell death causes neurodegeneration in the brain of HD patients.

In a new study, Tokyo Medical and Dental University-led researchers examined the nature of cell death in HD using newly developed imaging techniques. The effects of mutant huntingtin in neuronal cells were visualized by live cell imaging. With this approach, the authors identified a novel type of cell death associated with mutant huntingtin, which they called ballooning cell death (BCD). These cells gradually expanded like a balloon, until they ruptured.

To characterize the specific nature of BCD, the authors examined different cellular organelles by live cell imaging. “The endoplasmic reticulum was the main origin of ballooning,” study first author Ying Mao explains. “Rupture of the endoplasmic reticulum into the cytosol was followed by gradual cell body ballooning, nuclear shrinkage, and cell rupture.”

Image shows a diagram explaining apoptosis.

The authors observed the same phenomena in vivo using two-photon endoplasmic reticulum imaging in a HD mouse model.

Pharmacological inhibitors and genetic interventions showed that BCD was not like apoptosis or autophagy. “We noticed multiple similarities between BCD and a unique form of necrosis called TRIAD, which is caused by inhibition of RNA polymerase II in neurons,” corresponding author Hitoshi Okazawa explains. “Based on our existing knowledge of how TRIAD is regulated, we were able to show that BCD is mediated by impaired TEAD/YAP transcription.”

These revelations provided the opportunity to test potential therapeutic targets for HD. The researchers introduced S1P and up-regulated TEAD/YAP transcription in HD mice.

This stabilized endoplasmic reticulum and completely stopped the decline of motor function, suggesting that targeting TEAD/YAP-dependent necrosis may lead to development of effective therapies for HD.

ABOUT THIS NEUROLOGY RESEARCH ARTICLE

Funding: The work was supported by Ministry of Education, Culture, Sports, Science and Technology, JAPAN.

Source: Hitoshi Okazawa – Tokyo Medical and Dental University
Image Source: This NeuroscienceNews.com image is credited to Department of Neuropathology,Medical Research Institute.
Original Research: Abstract for “Targeting TEAD/YAP-transcription-dependent necrosis, TRIAD, ameliorates Huntington’s disease pathology” by Ying Mao, Xigui Chen, Min Xu, Kyota Fujita, Kazumi Motoki, Toshikazu Sasabe, Hidenori Homma, Miho Murata, Kazuhiko Tagawa, Takuya Tamura, Julia Kaye, Steven Finkbeiner, Giovanni Blandino, Marius Sudol, and Hitoshi Okazawa in Human Molecular Genetics. Published online September 6 2016 doi:10.1093/hmg/ddw303

Tokyo Medical and Dental University. “Novel Type of Cell Death in Huntington’s Disease May Lead to Effective New Therapies.” NeuroscienceNews. NeuroscienceNews, 22 November 2016.
<http://neurosciencenews.com/huntingtons-cell-death-5583/&gt;.

Abstract

Targeting TEAD/YAP-transcription-dependent necrosis, TRIAD, ameliorates Huntington’s disease pathology

Neuronal cell death in neurodegenerative diseases is not fully understood.

Here we report that mutant huntingtin (Htt), a causative gene product of Huntington’s diseases (HD) selectively induces a new form of necrotic cell death, in which endoplasmic reticulum (ER) enlarges and cell body asymmetrically balloons and finally ruptures.

Pharmacological and genetic analyses revealed that the necrotic cell death is distinct from the RIP1/3 pathway-dependent necroptosis, but mediated by functional deficiency of TEAD/YAP-dependent transcription.

In addition, we revealed that a cell cycle regulator, Plk1, switches the balance between TEAD/YAP-dependent necrosis and p73/YAP-dependent apoptosis by shifting the interaction partner of YAP from TEAD to p73 through YAP phosphorylation at Thr77.

In vivo ER imaging with two-photon microscopy detects similar ER enlargement, and viral vector-mediated delivery of YAP as well as chemical inhibitors of Hippo pathway such as S1P recover the ER instability and necrosis in HD model mice. Intriguingly S1P completely stops the decline of motor function of HD model mice even after the onset of symptom. Collectively, we suggest approaches targeting the signaling pathway of TEAD/YAP-transcription-dependent necrosis (TRIAD) could lead to a therapeutic development against HD.

“Targeting TEAD/YAP-transcription-dependent necrosis, TRIAD, ameliorates Huntington’s disease pathology” by Ying Mao, Xigui Chen, Min Xu, Kyota Fujita, Kazumi Motoki, Toshikazu Sasabe, Hidenori Homma, Miho Murata, Kazuhiko Tagawa, Takuya Tamura, Julia Kaye, Steven Finkbeiner, Giovanni Blandino, Marius Sudol, and Hitoshi Okazawa in Human Molecular Genetics. Published online September 6 2016 doi:10.1093/hmg/ddw303

Causal Link Between Alzheimer’s Disease and Telomere Shortening

In a newly published study, researchers at Karolinska Institutet show that the shortening of the telomeres – the caps at each end of the chromosomes in our cells – can be linked statistically to the active mechanism responsible for Alzheimer’s disease. However, the effect is small and telomere length cannot yet be used to assess disease risk at an individual level. The results are presented in the journal JAMA Neurology.

Every cell in our body contains our entire genome, packed into the nucleus in the form of 46 chromosomes. Every time a cell divides, the telomeres at the tips of the chromosomes become slightly shorter until they reach a critical length, at which point the cell dies. Just where this critical threshold goes depends on the individual, partly because the telomeres are of different lengths to start with, and partly because in some people the telomeres shorten more on cell division than in others. The shortening process takes place when we age, but previously telomere length was only used as a marker for biological ageing.

For the first time, a group of scientists at the Department of Medical Epidemiology and Biostatistics at Karolinska Institutet has shown that telomere length is causally linked to the risk of developing Alzheimer’s disease.

“That there’s some kind of link between telomere length and the risk of Alzheimer’s disease is nothing new in itself, but it was thought that it was down to other underlying commonalities,” says principal investigator Dr Sara Hägg, docent of molecular epidemiology. “In this study we’ve been able to show that the telomeres are involved in the actual active mechanism behind the development of the disease, which is completely new and very interesting.”

The entire genome

To arrive at their results, the researchers used data from studies that identified gene variants linked to telomere length and to Alzheimer’s disease by examining the entire genome. By using a special study design, they were then able to show statistically the presence of a causal link between short telomeres and a higher risk of Alzheimer’s disease. The researchers stress, however, that since the telomere process is so complex, nothing can be said about the degree of an individual person’s risk from the mere measurement of their telomeres.

Image shows telomeres.

“What’s more, the effects are very small,” adds Dr Hägg. “But from a biological perspective, they’re very interesting.”

ABOUT THIS ALZHEIMER’S DISEASE RESEARCH

Funding: The study was financed with grants from various bodies, including the Loo and Hans Österman Foundation, FORTE, the Swedish Research Council, KID-grant from Karolinska Institutet for doctoral education, and the Foundation for Geriatric Diseases at Karolinska Institutet.

Source: Katarina Sternudd – Karolinska Institute
Image Source: The image is credited to Reinhard Stindl and is licensed CC BY-SA 3.0
Original Research: Abstract for “Telomere Length Shortening and Alzheimer Disease—A Mendelian Randomization Study” by iqiang Zhan, MD; Ci Song, PhD; Robert Karlsson, PhD; Annika Tillander, PhD; Chandra A. Reynolds, PhD; Nancy L. Pedersen, PhD; and Sara Hägg, PhD in JAMA Neurology. Published online October 2015 doi:10.1001/jamaneurol.2015.1513


Abstract

Telomere Length Shortening and Alzheimer Disease—A Mendelian Randomization Study

This study explores the causal effect of telomere length on Alzheimer disease by applying the mendelian randomization method to summary genome-wide association study data.

Telomeres are sequences of repetitive nucleotides at the end of the chromosomes, which protect them from fusion with neighboring chromosomes.1 Observational studies have found associations between shorter telomeres and Alzheimer disease (AD).2 However, these studies could have residual confounding or reverse causation, making it difficult to draw conclusions on whether telomere length (TL) is causally associated with AD. For the past decades, instrumental variable (IV) analysis has been developed for assessing causality using genetic variants in epidemiological research under the name of mendelian randomization (MR).3 In the present study, we investigated the causal effect of TL on AD by applying the MR method to summary genome-wide association study (GWAS) data from Codd et al4 and from the International Genomics of Alzheimer’s Project Consortium.5

“Telomere Length Shortening and Alzheimer Disease—A Mendelian Randomization Study” by iqiang Zhan, MD; Ci Song, PhD; Robert Karlsson, PhD; Annika Tillander, PhD; Chandra A. Reynolds, PhD; Nancy L. Pedersen, PhD; and Sara Hägg, PhD in JAMA Neurology. Published online October 2015 doi:10.1001/jamaneurol.2015.1513

What is your molecular age? P16 protein can ID your molecular age

Aging biomarket test –  coming soon

Researchers report the development of a new blood test that they say may show your “molecular age,” as opposed to your chronological age.

That test measures levels of a protein called p16. A new study shows that p16 levels rise as people age, that smokers have higher levels of p16 than nonsmokers, and that people who exercise have lower levels of p16.

The test isn’t available to the public yet. But if it was, would you want to know your “molecular age”?

Let’s say you took the test and found out your molecular age was greater than your chronological age, suggesting that your aging process is on the fast track. Or maybe you’d find out that the opposite is true, that your clock isn’t ticking quite as fast as you thought.

What would you do with that information? Would it spur you to make lifestyle changes to try to stave off aging, or would you be looking for reassurance that your healthy habits are paying off?

Role in senescence

Concentrations of p16INK4a increase dramatically as tissue ages. p16INK4a, along with senescence-associated beta-galactosidase, is regarded to be a biomarker of cellular senescence.[32] Therefore, p16INK4a could potentially be used as a blood test that measures how fast the body’s tissues are aging at a molecular level.[33]

It has been used as a target to delay some aging changes in mice. P16 along with SABG can be a biomarker of cellular senescence.

Senescence-associated beta-galactosidase (SA-β-gal or SABG) is a hypothetical hydrolase enzyme that catalyzes the hydrolysis of β-galactosidesinto monosaccharides only in senescent cells. Senescence-associated beta-galactosidase, along with p16Ink4A, is regarded to be a biomarker of cellular senescence.[1]

Its existence was proposed in 1995 by Dimri et al.[2] following the observation that when beta-galactosidase assays were carried out at pH 6.0, only cells in senescence state develop staining. They proposed a cytochemical assay based on production of a blue-dyed precipitate that results from the cleavage of the chromogenic substrate X-Gal. Since then, even more specific quantitative assays were developed for its detection at pH 6.0.[3][4][5]

Today this phenomenon is explained by the overexpression and accumulation of the endogenous lysosomal beta-galactosidase specifically in senescent cells.[6] Its expression is not required for senescence. However, it remains as the most widely used biomarker for senescent and aging cells, because it is easy to detect and reliable both in situ and in vitro.

P16 Role in cancer

Mutations resulting in deletion or reduction of function of the CDKN2A gene are associated with increased risk of a wide range of cancers and alterations of the gene are frequently seen in cancer cell lines.[13][14] Examples include:

Pancreatic adenocarcinoma is often associated with mutations in the CDKN2A gene.[15][16][17]

Carriers of germline mutations in CDKN2A have besides their high risks of melanoma also increased risks of pancreatic, lung, laryngeal and oropharyngeal cancers and tobacco smoking exacerbates carriers’ susceptibility for such non-melanoma cancers.[18]

Homozygous deletion of p16 are frequently found in esophageal cancer and gastric cancer cell lines.[19]

Germline mutations in CDKN2A are associated with an increased susceptibility to develop skin cancer.[20]

Hypermethylation of tumor suppressor genes has been implicated in various cancers. In 2013, a meta-analysis of 39 articles using analysis cancer tissues and 7 articles using blood samples, revealed an increased frequency of DNA methylation of p16 gene in esophageal cancer. As the degree of tumor differentiation increased, so did the frequency of DNA methylation.

Tissue samples of primary oral squamous cell carcinoma (OSCC) display hypermethylation in the promoter regions of p16. Cancer cells show a significant increase in the accumulation of methylation in CpG islands in the promoter region of p16. This epigenetic change leads to the loss of tumor suppressor gene function through two possible mechanisms. Methylation can physically inhibit the transcription of the gene or methylation can lead to the recruitment of transcription factors that repress transcription. Both mechanisms lead to the same end result—downregulation of gene expression that leads to decreased levels of the p16 protein. It has been suggested that this process is responsible for the development of various forms of cancer serving as an alternative process to gene deletion or mutation.[21][22][23][24][25][26]

Clinical use

Use as a biomarker

Furthermore, p16 is now being explored as a prognostic biomarker for a number of cancers. For patients with oropharyngeal squamous cell carcinoma, using immunohistochemistry to detect the presence of the p16 biomarker has been shown to be the strongest indicator of disease course. Presence of the biomarker is associated with a more favorable prognosis as measured by cancer-specific survival (CSS), recurrence-free survival (RFS), locoregional control (LRC), as well as other measurements. The appearance of hyper methylation of p16 is also being evaluated as a potential prognostic biomarker for prostate cancer.[27][28][29]

p16 FISH

p16 deletion detected by FISH in surface epithelial mesothelial proliferations is predictive of underlying invasive mesothelioma.[30]

p16 immunochemistry

Gynecologic cancers

p16 is a widely used immunohistochemical marker in gynecologic pathology. Strong and diffuse cytoplasmic and nuclear expression of p16 in squamous cell carcinomas (SCC) of the female genital tract is strongly associated with high-risk human papilloma virus (HPV) infection and neoplasms of cervical origin. The majority of SCCs of uterine cervix express p16. However, p16 can be expressed in other neoplasms and in several normal human tissues.[31]

Urinary bladder SCCs

More than a third of urinary bladder SCCs express p16. SCCs of urinary bladder express p16 independent of gender. p16 immunohistochemical expression alone cannot be used to discriminate between SCCs arising from uterine cervix versus urinary bladder.[31]

Email motherhealth@gmail.com if you want more info on testing your molecular age next year as we will add this service at avatarcare.net  soon.


P16 (gene) has been shown to interact with:

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Exercise your brain with cross-fit training

It’s been three months with a crossfit training coach at NC Fit when my coach asked me why I attend my 30min group training every day. I told my coach Brandon, that I wanted to increase 10 yrs in my life. I want to help raise my future grandchildren and be able to experience life everyday and share it with others.

http://nc.fit/memberships

Mention my name (Connie Dello Buono) when joining this cross fit gym in the bay area. My team asked what I eat for breakfast and I said one pouched egg and Roibois tea. I also use VEGA protein powder and Garden of Life after working out. My mom cooks fish and veggie for me and my friend shares his garden produce with me.

I want to be a good example for my children and hopefully I will not spend any fortune when it is time for me to be taken cared for during old age.

I worked two jobs, sending my children to college and some nieces in the Philippines to college. I have a fitness and financial goals.

NC Fit cross fit.JPG

Stronger immune system, less Alzheimer’s symptoms

IL-33 is effective in reversing Alzheimer-like symptoms in APP/PS1 mice

(from WIKI)

Interleukin 33 (IL33) is a protein that in humans is encoded by the IL33 gene.[1]

Interleukin 33 is a member of the IL-1 family that potently drives production of T helper-2 (Th2)-associated cytokines (e.g., IL-4). IL33 is a ligand for IL33R (IL1RL1), an IL-1 family receptor that is highly expressed on Th2 cells, mast cells and group 2 innate lymphocytes.

IL33 and AD

IL-33 is expressed on a wide variety of cell types, including fibroblasts, mast cells, dendritic cells, macrophages, osteoblasts, endothelial cells, and epithelial cells.[3]

IL-33 is effective in reversing Alzheimer-like symptoms in APP/PS1 mice, by reversing the buildup and preventing the new formation of amyloid plaques.[4]

IL-33 protein injection in AD mouse models alleviates Alzheimer’s symptoms

While the mechanisms underlying the onset and progression of AD remain unclear, scientists from the Hong Kong University of Science and Technology (HKUST) recently conducted a study on the potential therapeutic role of interleukin-33 (IL-33) in AD, where they injected the protein into transgenic mouse models of AD. The injection of IL-33 rescues contextual memory deficits and reduces the deposition of β-amyloid peptide (Aβ) in the transgenic mouse model, suggesting that IL-33 can be developed as a new therapeutic intervention for AD.

The findings were published in the journal PNAS.

“There is no effective therapy for AD, in part because of our limited knowledge of its underlying pathophysiological mechanisms,” said Prof Nancy Ip, Dean of Science, Director of the State Key Laboratory of Molecular Neuroscience and The Morningside Professor of Life Science at HKUST, who directed the research effort. “Nonetheless, targeting the innate immune system has been considered a promising strategy for developing effective ther

apeutics for AD. The present study demonstrates that peripheral IL-33 injection in AD mouse models alleviates AD-like pathology by enhancing microglial phagocytosis and degradation of Aβ.”

“We believe that IL-33 is a critical factor in maintaining a healthy brain,” Prof Ip said. “Disturbances in this signal mechanism, owing to genetic disposition or environmental influence, may contribute to the onset of AD. The next step will be to translate the findings from the mouse study into clinical treatments for humans.”

The research was the result of a collaborative effort among scientists from HKUST, the University of Glasgow, and Zhejiang University.

Explore further: Breakthrough research reveals a new target for Alzheimer’s disease treatment

More information: Amy K. Y. Fu et al, IL-33 ameliorates Alzheimer’s disease-like pathology and cognitive decline, Proceedings of the National Academy of Sciences (2016). DOI: 10.1073/pnas.1604032113

Journal reference: Proceedings of the National Academy of Sciences search and more info website

Provided by: Hong Kong University of Science and Technology

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Role of IL-33 in the inflammation of several disease

Interleukin (IL)-33 is a new member of the IL-1 superfamily of cytokines that is expressed by mainly stromal cells, such as epithelial and endothelial cells, and its expression is upregulated following pro-inflammatory stimulation. IL-33 can function both as a traditional cytokine and as a nuclear factor regulating gene transcription. It is thought to function as an ‘alarmin’ released following cell necrosis to alerting the immune system to tissue damage or stress. It mediates its biological effects via interaction with the receptors ST2 (IL-1RL1) and IL-1 receptor accessory protein (IL-1RAcP), both of which are widely expressed, particularly by innate immune cells and T helper 2 (Th2) cells. IL-33 strongly induces Th2 cytokine production from these cells and can promote the pathogenesis of Th2-related disease such as asthma, atopic dermatitis and anaphylaxis.

However, IL-33 has shown various protective effects in cardiovascular diseases such as atherosclerosis, obesity, type 2 diabetes and cardiac remodeling. Thus, the effects of IL-33 are either pro- or anti-inflammatory depending on the disease and the model. In this review the role of IL-33 in the inflammation of several disease pathologies will be discussed, with particular emphasis on recent advances.

Basic Biology of IL-33

Interleukin (IL)-33 (also known as IL-1F11) was originally identified as DVS27, a gene up-regulated in canine cerebral vasospasm [1], and as “nuclear factor from high endothelial venules” (NF-HEV) [2]. However, in 2005 analysis of computational structural databases revealed that this protein had close amino acid homology to IL-18, and a β-sheet trefoil fold structure characteristic of IL-1 family members [3]. IL-33 binds to a ST2L (also known as T1, IL-1RL1, DER4), which is a member of the Toll-like receptor (TLR)/IL1R superfamily. IL-33/ST2L then forms a complex with the ubiquitously expressed IL-1R accessory protein (IL-1RAcP) [4-6]. Signaling is induced through the cytoplasmic Toll-interleukin-1 receptor (TIR) domain of IL-1RAcP. This leads to recruitment of the adaptor protein MyD88 and activation of transcription factors such as NF-κB via TRAF6, IRAK-1/4 and MAP kinases and the production of inflammatory mediators (Figure (Figure1)1) [3]. The ST2 gene can also encode at least 2 other isoforms in addition to ST2L by alternative splicing, including a secreted soluble ST2 (sST2) form which can serve as a decoy receptor for IL-33 [7], and an ST2V variant form present mainly in the gut of humans [8].

Signaling through ST2L also appears to be negatively regulated by the molecule single Ig IL-1R-related molecule (SIGIRR) and IL-33 induced immune responses were enhanced in SIGIRR-/- mice [9].

IL-33 release and signaling via ST2L. IL-33 is predominantly expressed by stromal cells such as epithelial and endothelial cells. Damage to these cells can induce necrosis and release of full length IL-33 which can activate the heterodimeric ST2L/IL-1RAcP …

IL-33 appears to be a cytokine with dual function, acting both as a traditional cytokine through activation of the ST2L receptor complex and as an intracellular nuclear factor with transcriptional regulatory properties [10].

The amino terminus of the IL-33 molecule contains a nuclear localization signal and a homeodomain (helix-turn-helix-like motif) that can bind to heterochromatin in the nucleus and has similar structure to the Drosophila transcription factor engrailed [2,11].

In a similar manner to which a motif found in Kaposi sarcoma herpesvirus LANA (latency-associated nuclear antigen) attaches its viral genomes to mitotic chromosomes.

Nuclear IL-33 is thought to be involved in transcriptional repression by binding to the H2A-H2B acidic pocket of nucleosomes and regulating chromatin compaction by promoting nucleosome-nucleosome interactions [12].

However, the specific transcriptional targets or the biological effects of nuclear IL-33 are unclear at present.

Both IL-1β and IL-18 are synthesized as a biologically inactive precursors and activated by caspase-1 cleavage under pro-inflammatory conditions and it was initially thought that IL-33 underwent similar processing by caspase-1 [3].

Recent studies suggest that proteolytic processing is not required for IL-33 signaling via ST2L [13]. It has been suggested that a new splice variant of IL-33 exists, which lacks the putative caspase-1 cleavage site, and is biologically active inducing signaling via ST2L [14].

In fact, cleavage of IL-33 by caspases appears to mediate inactivation of IL-33 and its pro-inflammatory properties [13,15-17]. Currently, it is thought that full length biologically active IL-33 may be released during necrosis as a endogenous danger signal or ‘alarmin’, but during apoptosis IL-33 is cleaved by caspases leading to inactivation of its pro-inflammatory properties [18].

IL-33, an inducer of Th2 immune responses

Unlike the other IL-1 family members IL-33 primarily induces T helper 2 (Th2) immune responses in a number of immune cell types (reviewed in detail in [19]). ST2L was initially shown to be selectively expressed on Th2, but not Th1 [20,21] or regulatory (Treg) T cells [22].

Subsequent studies have shown that IL-33 can activate murine dendritic cells directly driving polarization of naïve T cells towards a Th2 phenotype [23], and it can act directly on Th2 cells to increase secretion of Th2 cytokines such as IL-5 and IL-13 [3,24].

Furthermore, IL-33 can also act as a chemo-attractant for Th2 cells [25]. IL-33 can activate B1 B cells in vivo, markedly enhancing production of IgM antibodies and IL-5 and IL-13 production from these cells [3,26,27].

IL-33 is also a potent activator of the innate immune system

IL-33 is also a potent activator of the innate immune system. Schmitz and co-workers demonstrated that injection of IL-33 into mice induces a profound eosinophilia [3], and has potent effects on this cell type, including induction of superoxide anion and IL-8 production, degranulation and cell survival [28].

Subsequently, it has been shown that IL-33 is also a potent activator of mast cells and basophils and can induce degranulation, maturation, promote survival and the production of several pro-inflammatory cytokines in these cells [29-32].

In neutrophils, IL-33 prevents the down-regulation of CXCR2 and inhibition of chemotaxis induced by the activation of TLR4 [33]. Macrophages constitutively express ST2L and IL-33 can amplify an IL-13-driven polarization of macrophages towards an alternatively activated or M2 phenotype, thus enhancing Th2 immune responses [34]. IL-33 can also enhance LPS-induced production of TNFα in these cells [35].

Host defense against pathogens

It is likely that the primary role of these IL-33 effects on the immune system in evolutionary terms was in host defense against pathogens. In fact, IL-33/ST2 have been shown to be highly expressed and protective several parasite infections in animal models in which Th2 cells are host protective, including Leishmania major [36,37], Toxoplasma gondii [38], Trichuris muris [39], and Nippostrongylus brasiliensis [40]. Furthermore, a recent discovery has highlighted a new population of cells named nuocytes which expand in response to IL-33 and represent the predominant early source of IL-13 during helminth infection with Nippostrongylus brasiliensis [41]. However, it is clear that the potent activatory effects of IL-33 on several immune cell types is likely to impact on various inflammatory diseases.

Role of the IL-33/ST2 pathway in inflammatory diseases

Asthma

Asthma is a chronic inflammatory disease classically characterized by airway hyper-responsiveness, allergic inflammation, elevated serum IgE levels, and increased Th2 cytokine production. Given that IL-33 is a strong inducer of Th2 immune responses its role in asthma has been extensively studied (reviewed in [42]). Initial gene expression studies in a range of tissues using human and mouse cDNA libraries revealed expression of IL-33 in lung tissue, and high expression in bronchial smooth muscle cells [3].

Expression of IL-33 was found in higher levels in endobronchial biopsies from human asthmatic subjects compared to controls.

The IL-33 expression was particularly evident in those with severe asthma and the expression was mainly located in bronchial epithelial cells.

Studies to investigate which cells were the main IL-33 responsive cells in lung demonstrated that both epithelial and endothelial cells, but not smooth muscle cells or fibroblasts were important .

Several animal model studies have highlighted a functionally important role for IL-33/ST2 in asthma and allergic airways inflammation.

In a murine ovalbumin-induced airway inflammation model, intranasal administration of IL-33 induces antigen-specific IL-5+ T cells and promotes allergic airway disease even in the absence of IL-4 [24].

Intranasal IL-33 also promotes airways hyper-responsiveness, goblet cell hyperplasia, eosinophilia, polarization of macrophages towards an M2 phenotype, and accumulation of lung IL-4, IL-5 and IL-13.

More recently, an IL-33 transgenic mouse was generated in which IL-33 expression was controlled under a CMV promoter and released as a cleaved 18 kDa protein in pulmonary tissue .

These mice developed massive airway inflammation with infiltration of eosinophils, hyperplasia of goblet cells and accumulation of pro-inflammatory cytokines in bronchoalveolar lavage fluid.

In contrast, intraperitoneal anti-IL-33 antibody treatment inhibited allergen-induced lung eosinophilic inflammation and mucus hypersecretion in a murine model.

Administration of blocking anti-ST2 antibodies or ST2-Ig fusion protein inhibited Th2 cytokine production in vivo, eosinophilic pulmonary inflammation and airways hyper-responsiveness.

At present, the role of IL-33/ST2 in studies using ST2-deficient mice is unclear as these mice are not protected in the ovalbumin-induced airway inflammation model but have attenuated inflammation in a short-term priming model of asthma.

Furthermore, there is also an exacerbation of disease in wild-type or Rag-1-/- mice that had undergone adoptive transfer of ST2-/- DO11.10 Th2 cells [24,51,52].

In order to clarify the role of IL-33/ST2 in lung inflammation, several groups have generated mice deficient in IL-33. Oboki and co-workers demonstrated that 2 sensitizations of IL-33-/- mice with ovalbumin emulsified in alum showed attenuated eosinophil and lymphocyte recruitment to the lung, airway hyper-responsiveness and inflammation [19].

A similar study by Louten and colleagues has also shown that endogenous IL-33 contributes to airway inflammation and peripheral antigen-specific responses in ovalbumin-induced acute allergic lung inflammation using IL-33-/- mice [53]. Collectively, the data suggest that IL-33 is involved in lung inflammation and supports the concept of ST2 as a therapeutic target in asthma.

Rheumatological diseases

Recent evidence suggests a role for IL-33/ST2 in several rheumatological diseases, including rheumatoid arthritis (RA), osteoarthritis (OA), psoriatic arthritis (PsA) and systemic lupus erythematosus (SLE). The first study to link IL-33 expression with arthritis utilized in situ hybridization to show that IL-33 mRNA expression in the RA synovium is primarily in endothelial cells [11]. Subsequently, IL-33 protein has been found in endothelial cells of synovial tissue and in cells morphologically consistent with synovial fibroblasts in a subset of RA, PsA and OA patients [54]. IL-33 is also expressed in cultured synovial fibroblasts from patients with RA and expression was markedly elevated in vitro by inflammatory cytokines [55,56]. Circulating IL-33 protein has also been detected in 94/223 RA patient serum samples by ELISA, but was completely absent in healthy controls or OA samples [57]. Furthermore, the level of serum IL-33 decreased after anti-TNF treatment and correlated with production of IgM and RA-related autoantibodies including Rheumatoid Factor and anti-citrullinated protein antibodies. Serum and synovial fluid levels of IL-33 have also been shown to decrease in patients who respond to anti-TNF treatment, while they did not change in non-responders [58]. Similarly, Talabot-Ayer and co-workers show that serum and synovial fluid IL-33 levels were higher in RA than in OA patients, and undetectable in PsA serum and synovial fluid [54]. Another study has demonstrated that neutrophils from patients with RA successfully treated with anti-TNF treatment expressed significantly lower levels of ST2 than patients treated with methotrexate alone [59]. In SLE, one study has shown serum IL-33 levels were significantly increased, compared with healthy controls, but to a lower extent than in patients with RA [60]. The other study reported no change in serum IL-33 levels between controls and SLE patients, but did report a significant increase in sST2 that correlated with SLE disease activity [61].

In murine models of RA, IL-33 mRNA has also been detected in the joints of mice undergoing collagen-induced arthritis (CIA) [56], and in mouse knee joints injected with methylated bovine serum albumin [59]. Furthermore, ST2-/- mice developed attenuated CIA and reduced ex vivo collagen-specific induction of pro-inflammatory cytokines (IL-17, TNFα, and IFNγ), and antibody production [55]. Conversely, treatment with IL-33 exacerbated CIA and elevated production of both pro-inflammatory cytokines and anti-collagen antibodies through a mast cell-dependent pathway. Administration of blocking anti-ST2 antibodies at the onset of CIA also attenuated the severity of disease and reduced joint destruction [56]. This was also associated with reduced IFNγ and IL-17 production. In a model of anti-glucose-6-phosphate isomerase autoantibody-induced arthritis, IL-33 treatment exacerbated disease. Conversely, ST2-/- mice were protected against disease and had reduced expression of articular pro-inflammatory cytokines [62]. The IL-33 effects in this model also appear to be mast cell-dependent as IL-33 failed to increase the severity of the disease in mast cell-deficient mice, and mast cells from wild-type, but not ST2-/- mice restored the ability of ST2-/- recipients to respond. IL-33 has also been shown to chemoattract neutrophils to a knee joint injected with methylated bovine serum albumin [59].

Various rheumatological diseases can have effects on bone including erosion (e.g. RA) and ossification and the formation of new bone (e.g., ankylosing spondylitis and OA). Recently, the role of IL-33 in bone metabolism and remodeling has been studied with conflicting results. Bone structure and metabolism are determined by the formation and activity of osteoclasts and osteoblasts. Mun and co-workers showed that IL-33 can stimulate the formation of multi-nuclear osteoclasts from monocytes, and enhanced expression of osteoclast differentiation factors including TRAF6, nuclear factor of activated T cells cytoplasmic 1, c-Fos, c-Src, cathepsin K, and calcitonin receptor [63]. However, in contrast two other studies have shown that IL-33 completely abolished the generation of multinucleated osteoclasts [64] or had no direct effect [65,66].

IL-33 also appears to have direct effects on osteoblast cells. IL-33 expression increases during osteoblast differentiation, and that while ST2-/- mice displayed normal bone formation they had increased bone resorption, thereby resulting in low trabecular bone mass [64]. Furthermore, IL-33 mRNA levels are increased in osteoblasts following treatment with the bone anabolic factors parathyroid hormone or oncostatin M. In addition, IL-33 treatment promoted matrix mineral deposition by osteoblasts in vitro [65]. However, a recent study reports conflicting data that while IL-33 mRNA is present in human osteoblasts, ST2L is not constitutively expressed and IL-33 treatment has no effect on these cells [66]. The reasons for these differences in the biology of IL-33 in osteoclasts and osteoblasts are unclear at present but may reflect different cell culture conditions and differentiation protocols used. In summary, IL-33 appears to have pro-inflammatory effects in various rheumatological diseases activating synovial fibroblasts and mast cells within joints.

Inflammatory skin disorders

Skin and activated dermal fibroblasts contain a high level of IL-33 mRNA expression compared to other tissues and cell types [3]. IL-33 mRNA and protein is also substantially higher in the skin lesions of patients with atopic dermatitis compared with non-inflamed skin samples [67], and in affected psoriatic skin compared to healthy skin [68,69]. Elevated serum IL-33 levels have also been detected in patients with systemic sclerosis, and levels correlated positively with the extent of skin sclerosis [70]. Furthermore, subcutaneous administration of IL-33 can induce IL-13-dependent fibrosis of skin in murine models [71]. Recently, it was shown that ST2-/- mice exhibited reduced cutaneous inflammatory responses compared to WT mice in a phorbol ester-induced model of skin inflammation [69]. Furthermore, intradermal injections of IL-33 into the ears of mice induced a psoriasis-like inflammatory lesion that was partially dependent on mast cells.

In addition, IL-33 expression was induced in pericytes in an experimental model of wound healing in rat skin [72]. Surprisingly, IL-33 has also been shown to induce cutaneous hypernociception in mice, a phenomenon traditionally associated with Th1 responses [73]. Collectively, these results demonstrate that IL-33 may play a role in various inflammatory skin disorders (Figure (Figure22).

Schematic representation of the potential pro-inflammatory role of IL-33 in normal skin and in skin inflammation (atopic dermatitis and psoriasis). Damage to the skin such as by scratching in response to an allergen and inflammation lead to cell necrosis …

Inflammatory bowel disease (IBD)

IBD is a group of chronic inflammatory conditions of the colon and small intestine, including ulcerative colitis (UC) and Crohn’s disease, resulting from dysregulated immune responses. Several studies report an upregulation of IL-33 mRNA in human biopsy specimens from untreated or active UC patients compared to controls [72,74-77]. The main sites of UC IL-33 expression were myofibroblasts and epithelial cells. Similarly, ST2 transcripts have been detected in mucosa samples from patients with active UC [74,75]. However, although Carriere and co-workers demonstrated expression of IL-33 in endothelial cells of Crohn’s disease intenstine [11], subsequent studies have failed to demonstrate a significant role for IL-33 in Crohn’s disease [72,74,76]. Serum IL-33 and sST2 levels were elevated in UC patients compared with controls, while anti-TNF treatment decreased circulating IL-33 and increased sST2, thus favorably altering the ratio of the cytokine with its decoy receptor [74]. However, in other studies serum concentrations of IL-33 were low or did not differ between UC patients and healthy controls [75,78].

Several murine studies highlight a role for IL-33 in innate-type immunity in the gut. Mice treated with IL-33 displayed epithelial hyperplasia and eosinophil/neutrophil infiltration in the colonic mucosa [3]. Furthermore, in a murine model of T-cell independent dextran sodium sulphate (DSS)-induced colitis IL-33-/- mice had enhanced viability, compared to wild-type controls [19]. In a related study macrophage-specific transgenic mice that express a truncated TGF-β receptor II under control of the CD68 promoter (CD68TGF-βDNRII) and subjected to the DSS model of colitis display an impaired ability to resolve colitic inflammation but also an increase in IL-33+ macrophages compared to controls [79]. In addition, IL-33 mRNA is upregulated in the ilea and correlates with disease severity in a murine model of Th1/Th2-mediated enteritis, and induced IL-17 production from mesenteric lymph node cells stimulated ex vivo [74]. In summary, the IL-33/ST2 pathway may be an important regulator of UC, but be of less importance in Crohn’s disease.

Central nervous system (CNS) inflammation

Basal IL-33 mRNA levels are extremely high in the brain and spinal cord [3], and are elevated under conditions such as experimental subarachnoid hemorrhage [1]. Furthermore, expression of IL-33 in glial and astrocyte cultures is increased by Toll-like receptor ligands [80]. Treatment with IL-33 induces proliferation of microglia and enhances production of pro-inflammatory cytokines, such as IL-1β and TNFα, as well as the anti-inflammatory cytokine IL-10 [81]. It also enhances chemokines and nitric oxide production and phagocytosis by microglia. In mice, IL-33 levels and activity were increased in brains infected with the neurotropic virus Theiler’s murine encephalomyelitis virus [80]. Finally, a transcriptional analysis of brain tissue from patients with Alzheimer’s disease revealed that IL-33 expression was decreased compared to control tissues [82]. This study also demonstrated that 3 polymorphisms within the IL-33 gene resulting in a protective haplotype were associated with risk of Alzheimer’s disease [82]. This data is supported by a study in Chinese population with evidence that genetic variants of IL-33 affect susceptibility to Alzheimer’s disease [83]. Furthermore, cell-based assays demonstrate that IL-33 can decrease secretion of β-amyloid peptides [82]. Thus, IL-33 may have a role in regulating pathophysiology and inflammatory responses in the CNS.

Cancer

Although early reports document the expression of ST2 on leukaemic cell lines and on T cell lymphomas of patients [84,85], very few studies have addressed the role of IL-33/ST2 signaling on anti-tumor immune responses, tumor growth and/or metastasis. However, a recent study demonstrated that ST2-/- mice with mammary tumors have attenuated tumor growth and metastasis, with increased circulating levels of pro-inflammatory cytokines and activated NK and CD8+ T cells [86]. Furthermore, IL-33 induces proliferation, migration, and morphologic differentiation of endothelial cells, consistent with an effect on angiogenesis [87]. In addition, IL-33 expression is present in endothelial cells of healthy organs but is strikingly absent from those in tumors [88]. Therefore, IL-33 may be an important mediator in tumor escape from immune control and in tumor angiogenesis and thus warrants further investigation.

Cardiovascular (CV) disease

IL-33 was initially found in the nucleus of the high endothelial venules (HEV) of secondary lymphoid tissues [2]. More recently, IL-33 expression has been reported in coronary artery smooth muscle cells [3], coronary artery endothelium [89], non-HEV endothelial cells [88,90], adipocytes [66,91], and in cardiac fibroblasts suggesting that IL-33 may play a role in various CV disorders [92].

sST2 as a CV biomarker

This concept is supported by the clinical finding that the IL-33 decoy receptor sST2 was elevated in serum early after acute myocardial infarction (AMI), and correlated with creatine kinase and inversely correlated with left ventricular ejection fraction [93]. Since this primary observation several studies have since demonstrated the prognostic value of measuring serum sST2 in various CV diseases, showing that high baseline levels of sST2 were a significant predictor of CV mortality and heart failure (HF) (Table (Table1).1).

Taken together, these studies indicate that sST2 has the potential to be a predictive CV biomarker in patients with AMI, HF and dyspnea. Thus far, serum or plasma IL-33 has not been measured in CV disease. While levels are elevated in atopy [67], and some rheumatological diseases [57,58], the levels in CV disease are likely to be low (possibly due to elevated sST2 levels) and difficult to measure with currently available assays.

However, recent studies have highlighted the development of multiplex assays to measure low abundance IL-33 in serum or plasma and warrant further investigation in the context of CV disease [94]. In summary, sST2 shows promise as a biomarker predictive of mortality in several CV disorders.

Studies examining sST2 in serum/plasma of patients with CV disease

Cardiac fibrosis and hypertrophy

Studies in animal models suggest that sST2 is more than just a marker in CV disease and implicate IL-33/ST2 signaling as an important protective pathway in various CV diseases. In a model of pressure overload IL-33 treatment reduced cardiac hypertrophy and fibrosis, and improved survival following transverse aortic constriction in wild-type but not ST2-/- mice [92].

sST2 blocked the anti-hypertrophic effects of IL-33, indicating that sST2 functions in the myocardium as a soluble decoy receptor of IL-33. IL-33 can also reduce cardiomyocyte apoptosis, decrease infarct and fibrosis, and improve ventricular function in vivo via suppression of caspase-3 activity and increased expression of the ‘inhibitor of apoptosis’ family of proteins [95].

The protective effects of IL-33 may be limited by the neurohormonal factor endothelin-1, which increased expression of sST2 and inhibited IL-33 signaling through p38 MAP Kinase [96].

Atherosclerosis

During atherosclerosis immune cells such as monocytes, T cells and mast cells infiltrate plaques within the intima of the arterial wall [97]. The disease appears to be driven by a Th1 immune response with cytokines such as IL-12 and IFNγ inducing pathogenesis [98,99]. Thus, it was hypothesized that IL-33 may have protective effects during atherosclerosis by inducing a Th1-to-Th2 switch of immune responses.

Toll-like receptors (TLRs) and interleukin-1 receptors (IL-1Rs) have TIR intracellular domains that engage two main signaling pathways, via the TIR-containing adaptors MyD88 (which is not used by TLR3) and TRIF (which is used only by TLR3 and TLR4). Extensive studies in inbred mice in various experimental settings have attributed key roles in immunity to TLR- and IL-1R-mediated responses, but what contribution do human TLRs and IL-1Rs actually make to host defense in the natural setting?

Evolutionary genetic studies have shown that human intracellular TLRs have evolved under stronger purifying selection than surface-expressed TLRs, for which the frequency of missense and nonsense alleles is high in the general population. Epidemiological genetic studies have yet to provide convincing evidence of a major contribution of common variants of human TLRs, IL-1Rs, or their adaptors to host defense.

Clinical genetic studies have revealed that rare mutations affecting the TLR3-TRIF pathway underlie herpes simplex virus encephalitis, whereas mutations in the TIR-MyD88 pathway underlie pyogenic bacterial diseases in childhood. A careful reconsideration of the contributions of TLRs and IL-1Rs to host defense in natura is required.

Human TLRs and IL-1Rs in Host Defense: Natural Insights from Evolutionary, Epidemiological, and Clinical Genetics

Annual Review of Immunology

Vol. 29: 447-491 (Volume publication date April 2011)

First published online as a Review in Advance on January 3, 2011

DOI: 10.1146/annurev-immunol-030409-101335

Jean-Laurent Casanova,1,2 Laurent Abel,1,2 and Lluis Quintana-Murci3

1St. Giles Laboratory of Human Genetics of Infectious Diseases, The Rockefeller University, New York, NY 10021; email: casanova@rockefeller.edu

2Laboratory of Human Genetics of Infectious Diseases, INSERM U980, University Paris Descartes, Necker Medical School, Paris, France, EU

3Human Evolutionary Genetics, CNRS URA 3012, Institut Pasteur, Paris, France, EU

Roles of Epithelial Cell–Derived Type 2–Initiating Cytokines in Experimental Allergic Conjunctivitis

Yosuke Asada,1,2 Susumu Nakae,2 Waka Ishida,3 Kanji Hori,1 Jobu Sugita,1 Katsuko Sudo,4

Ken Fukuda,3 Atsuki Fukushima,3 Hajime Suto,5,6 Akira Murakami,1 Hirohisa Saito,7

Nobuyuki Ebihara,1 and Akira Matsuda1

1Laboratory of Ocular Atopic Diseases, Department of Ophthalmology, Juntendo University School of Medicine, Tokyo, Japan

2Frontier Research Initiative, Institute of Medical Science, University of Tokyo, Tokyo, Japan

3Department of Ophthalmology, Kochi University School of Medicine, Nangoku, Japan

4Animal Research Center, Tokyo Medical University, Tokyo, Japan

5Department of Dermatology, Juntendo University School of Medicine, Tokyo, Japan

6Atopy Research Center, Juntendo University School of Medicine, Tokyo, Japan

7Department of Allergy and Immunology, National Research Institute for Child Health and Development, Tokyo, Japan

 

 Intravenous Immunoglobulin Treatment in Humans Suppresses Dendritic Cell Function via Stimulation of IL-4 and IL-13 Production

Angela S. W. Tjon*, Rogier van Gent*,  Haziz Jaadar*,  P. Martin van Hagen†,  Shanta Mancham*,  Luc J. W. van der Laan‡,  Peter A. W. te Boekhorst§,  Herold J. Metselaar* and  Jaap Kwekkeboom*

Author Affiliations

*Department of Gastroenterology and Hepatology, Erasmus University Medical Center, Rotterdam 3015 CE, The Netherlands;

†Department of Internal Medicine and Immunology, Erasmus University Medical Center, Rotterdam 3015 CE, The Netherlands;

‡Department of Surgery, Erasmus University Medical Center, Rotterdam 3015 CE, The Netherlands; and

  • Department of Hematology, Erasmus University Medical Center, Rotterdam 3015 CE, The Netherlands

Address correspondence and reprint requests to Dr. Jaap Kwekkeboom, Department of Gastroenterology and Hepatology, Erasmus University Medical Center, Room Na-1009, 3015 CE Rotterdam, The Netherlands. E-mail address: j.kwekkeboom@erasmusmc.nl

Abstract

High-dose i.v. Ig (IVIg) is a prominent immunomodulatory therapy for various autoimmune and inflammatory diseases. Recent mice studies suggest that IVIg inhibits myeloid cell function by inducing a cascade of IL-33–Th2 cytokine production causing upregulation of the inhibitory FcγRIIb, as well as by modulating IFN-γ signaling.

The purpose of our study was to explore whether and how these mechanisms are operational in IVIg-treated patients. We show that IVIg in patients results in increases in plasma levels of IL-33, IL-4, and IL-13 and that increments in IL-33 levels correlate with rises in plasma IL-4 and IL-13 levels.

Strikingly, no upregulation of FcγRIIb expression was found, but instead a decreased expression of the activating FcγRIIa on circulating myeloid dendritic cells (mDCs) after high-dose, but not after low-dose, IVIg treatment. In addition, expression of the signaling IFN-γR2 subunit of the IFN-γR on mDCs was downregulated upon high-dose IVIg therapy. In vitro experiments suggest that the modulation of FcγRs and IFN-γR2 on mDCs is mediated by IL-4 and IL-13, which functionally suppress the responsiveness of mDCs to immune complexes or IFN-γ. Human lymph nodes and macrophages were identified as potential sources of IL-33 during IVIg treatment.

Interestingly, stimulation of IL-33 production in human macrophages by IVIg was not mediated by dendritic cell–specific intercellular adhesion molecule-3–grabbing nonintegrin (DC-SIGN). In conclusion, high-dose IVIg treatment inhibits inflammatory responsiveness of mDCs in humans by Th2 cytokine-mediated downregulation of FcγRIIa and IFN-γR2 and not by upregulation of FcγRIIb. Our results suggest that this cascade is initiated by stimulation of IL-33 production that seems DC-SIGN independent.

  • IgA. High levels of IgA may mean that monoclonal gammopathy of unknown significance (MGUS) or multiple myeloma is present. Levels of IgA also get higher in some autoimmune diseases, such as rheumatoid arthritis and systemic lupus erythematosus (SLE), and in liver diseases, such as cirrhosis and long-term (chronic) hepatitis.
  • IgG. High levels of IgG may mean a long-term (chronic) infection, such as HIV, is present. Levels of IgG also get higher in IgG multiple myeloma, long-term hepatitis, and multiple sclerosis (MS). In multiple myeloma, tumor cells make only one type of IgG antibody (monoclonal); the other conditions cause an increase in many types of IgG antibodies (polyclonal).
  • IgM. High levels of IgM can mean macroglobulinemia, early viral hepatitis, mononucleosis, rheumatoid arthritis, kidney damage (nephrotic syndrome), or a parasite infection is present. Because IgM antibodies are the type that form when an infection occurs for the first time, high levels of IgM can mean a new infection is present. High levels of IgM in a newborn mean that the baby has an infection that started in the uterus before delivery.
  • IgD. How IgD works in the immune system is not clear. A high level may mean IgD multiple myeloma is present. IgD multiple myeloma is much less common than IgA or IgG multiple myeloma.
  • IgE. A high level of IgE can mean a parasite infection is present. Also, high levels of IgE often are found in people who have allergic reactions, asthma, atopic dermatitis, some types of cancer, and certain autoimmune diseases. In rare cases, a high level of IgE may mean IgE multiple myeloma.