Molecule has potential to regulate immune response <:3

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Molecule has potential to regulate immune response <:3

Postby rainer » Thu Jul 03, 2008 8:08 pm

Please note mouse emoticon :!:

http://www.techjournalsouth.com/news/ar ... em_id=5651

AUGUSTA, GA - When a mouse's immune system is deciding whether to reject a skin graft, one powerful member of a molecular family designed to provoke such a response can effectively reduce the visibility of the mouse's own cells and help the graft survive, researchers say.

"This is a molecule with huge potential to regulate immune response," Dr. Anatolij Horuzsko, reproductive immunologist at the Medical College of Georgia Center for Molecular Chaperone/Radiobiology and Cancer Virology, says of HLA-G dimer.

Dimer appears to be the most powerful among several known forms of HLA-G at inhibiting the immune response, researchers have found. Fetuses use this natural mechanism to hide from the mother's immune system and it's at work in some transplant patients as well.

Now that the scientists know which HLA-G is best at down-regulating the immune response and how it works, they believe the molecule's action can be augmented in people with organ transplants and autoimmune disease and turned down to help fight a tumor.

Measuring endogenous levels of HLA-G dimer may also help physicians identify which transplant patients require little, if any, immune suppression.

Research published online in Proceedings of the National Academy of Sciences details that when HLA-G dimer binds with its inhibitory receptor, ILT4, it triggers a signaling pathway in which immune molecules IL-6 and STAT3 play a major role.

"Biologically this is an interaction that requires several important suppressive molecules," says Dr. Horuzsko, the study's corresponding author and a faculty member in the MCG Schools of Medicine and Graduate Studies.

They looked at the resulting strong signaling in culture, then measured its impact on skin graft survival in mice and found it prolonged survival.

Now Dr. Horuzsko is working with Dr. Laura Mulloy, chief of the Section of Nephrology, Hypertension and Transplantation Medicine in the MCG School of Medicine, to see if this dimer form is at work in kidney transplant patients who avoid rejection.

HLA-G dimer's target is another MHC molecule, which is essentially an individual's unique tissue signature; HLA-G itself is a type of MHC. In fact, HLA - human leukocyte antigen - matching is done for organ and bone marrow transplants to try minimize the recipient's reaction to the new organ.

Transplant patients also take drugs that broadly dampen the immune response but can leave them more vulnerable to infections and disease.

Dr. Horuzsko notes that HLA-G can work through other cells, not just MHC molecules, and that not every HLA-G form is good at down-regulating MHC.

He plans to look at HLA-G dimer levels in tumor patients as well. "Tumors already down- regulate MHC molecules," he says, referencing how tumors turn down their tissue expression so they can fly below the radar of the immune system.

"We need to see what form of HLA-G cancers - including leukemia, lymphoma, melanoma and breast cancer - use and see their level of expression." He notes that HLA-G isn't the only mechanism cancers use to escape the immune response but that being able to control a tumor's use of this molecule could offer a new way to target tumors for natural destruction.

A recent grant from the National Multiple Sclerosis Society is enabling studies of whether down-regulating MHC expression in multiple sclerosis patients can slow or arrest the immune system's attack of the nerve's protective covering.

"The expression of the MHC molecule for some reason goes up - an infection might trigger the recognition of your own tissue - and the immune system attacks," says Dr. Horuzsko.

"We can generate a mouse with MS-like disease and target the HLA-G inhibitory receptor to see if it effectively down-regulates the disease." He'll look to see which, if any, of the HLA-G forms are most powerful in this autoimmune scenario.
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FIGHT FIRE WITH FIRE

Postby gibbledygook » Fri Jul 04, 2008 6:11 am

I swear that capsaicin has transformed my leg over the last week...
maybe this is why:

1: Clin Cancer Res. 2007 May 15;13(10):3024-32. Links
Capsaicin is a novel blocker of constitutive and interleukin-6-inducible STAT3 activation.Bhutani M, Pathak AK, Nair AS, Kunnumakkara AB, Guha S, Sethi G, Aggarwal BB.
Cytokine Research Laboratory, Department of Experimental Therapeutics, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030, USA.

PURPOSE: Capsaicin, a constituent of green and red peppers, has been linked with suppression of tumorigenesis through a mechanism that is not well understood. Because the transcription factor signal transducer and activator of transcription 3 (STAT3) has been closely linked with tumorigenesis, we investigated the effect of this vanilloid on the STAT3 pathway in human multiple myeloma cells. EXPERIMENTAL DESIGN: The effect of capsaicin on both constitutive and interleukin-6-induced STAT3 activation, associated protein kinases, and STAT3-regulated gene products involved in proliferation, survival and angiogenesis, cellular proliferation, and apoptosis in multiple myeloma cells was investigated. RESULTS: We found that capsaicin inhibited constitutive activation of STAT3 in multiple myeloma cells in a dose- and time-dependent manner, with minimum effect on STAT5. Capsaicin also inhibited the interleukin-6-induced STAT3 activation. The activation of Janus-activated kinase 1 and c-Src, implicated in STAT3 activation, was also inhibited by the vanilloid, with no effect on extracellular signal-regulated kinase 1/2 activation. Pervanadate reversed the capsaicin-induced down-regulation of STAT3, suggesting the involvement of a protein tyrosine phosphatase. Capsaicin down-regulated the expression of the STAT3-regulated gene products, such as cyclin D1, Bcl-2, Bcl-xL, survivin, and vascular endothelial growth factor. Finally, capsaicin induced the accumulation of cells in G(1) phase, inhibited proliferation, and induced apoptosis, as indicated by caspase activation. Capsaicin also significantly potentiated the apoptotic effects of Velcade and thalidomide in multiple myeloma cells. When administered i.p., capsaicin inhibited the growth of human multiple myeloma xenograft tumors in male athymic nu/nu mice. CONCLUSION: Overall, these results suggest that capsaicin is a novel blocker of the STAT3 activation pathway, with a potential role in the prevention and treatment of multiple myeloma and other cancers.
<shortened url>
3 years antibiotics, 06/09 bilateral jug stents at C1, 05/11 ballooning of both jug valves, 07/12 stenting of renal vein, azygos & jug valve ballooning,
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Re: FIGHT FIRE WITH FIRE

Postby gwa » Fri Jul 04, 2008 6:37 am

gibbledygook wrote:I swear that capsaicin has transformed my leg over the last week...
maybe this is why:


What has it done for your leg? Are you eating a ton of green peppers or taking a supplement?

gwa
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Postby gibbledygook » Fri Jul 04, 2008 7:06 am

GWA I made the fabulous discovery, as recently as a week ago, that capsaicin ingested at a maximum of 2.4grams daily and applied topically to the nasal mucosa eliminates persistent, severe, chronic hayfever. After a few days of taking capsaicin and paying the price gastrointestinally I also realized that the spasticity in my leg was significantly improved and my bladder function stronger. Not to mention a now loose bowel!! The medicinal properties of these doses of capsaicin have been even more significant than the high dose curcumin which I'm also taking. I got the pills from an American health company. I don't know whether it's any different to ordinary chilli pepper but the pot says "capsicum" on it. But boy does it burn the stomach unless taken with food. I also think I know that it is the capsaicin as opposed to the other herbs I'm trialling (currently astragalus, skullcap, curcumin) because when I back off the capsaicin owing to gastrointestinal problems the stiffness reappears.
3 years antibiotics, 06/09 bilateral jug stents at C1, 05/11 ballooning of both jug valves, 07/12 stenting of renal vein, azygos & jug valve ballooning,
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Postby gibbledygook » Fri Jul 04, 2008 7:16 am

This is the real abstract as I found the news report rather vague:

1: Proc Natl Acad Sci U S A. 2008 Jun 17;105(24):8357-62. Epub 2008 Jun 11. Links
Modulation of dendritic cell differentiation by HLA-G and ILT4 requires the IL-6--STAT3 signaling pathway.Liang S, Ristich V, Arase H, Dausset J, Carosella ED, Horuzsko A.
Center for Molecular Chaperone/Radiobiology and Cancer Virology, Department of Medicine, Medical College of Georgia, 1410 Laney Walker Boulevard, Augusta, GA 30912, USA.

The expression of Ig-like transcript (ILT) inhibitory receptors is a characteristic of tolerogenic dendritic cells (DCs). However, the mechanisms of modulation of DCs via ILT receptors remain poorly defined. HLA-G is a preferential ligand for several ILTs. Recently, we demonstrated that triggering of ILT4 by HLA-G1 inhibits maturation of human monocyte-derived conventional DCs and murine DCs from ILT4 transgenic mice, resulting in diminished expression of MHC class II molecules, CD80 and CD86 costimulatory molecules, and prolongation of skin allograft survival. Different isoforms of HLA-G have diverse effects on the efficiency to induce ILT-mediated signaling. In this work, we show that HLA-G1 tetrameric complex and HLA-G5 dimer, but not HLA-G5 monomer, induce strong ILT-mediated signaling. We determined that the arrest of maturation of ILT4-positive DCs by HLA-G ligands involves the IL-6 signaling pathway and STAT3 activation. Ligation of ILT4 with HLA-G on DCs results in recruitment of SHP-1 and SHP-2 protein tyrosine phosphatases. We propose a model where SHP-2 and the IL-6-STAT3 signaling pathway play critical roles in the modulation of DC differentiation by ILT4 and HLA-G.


Unfortunately the URL link is just showing for pubmed at the moment.[/url]
3 years antibiotics, 06/09 bilateral jug stents at C1, 05/11 ballooning of both jug valves, 07/12 stenting of renal vein, azygos & jug valve ballooning,
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Fight fire with fire

Postby gibbledygook » Fri Jul 11, 2008 5:59 am

Here's another reason to try capsaicin:

1: J Pharmacol Exp Ther. 2001 Oct;299(1):238-46. Links
Capsaicin inhibits Jurkat T-cell activation by blocking calcium entry current I(CRAC).Fischer BS, Qin D, Kim K, McDonald TV.
Department of Medicine, Albert Einstein College of Medicine, Bronx, New York 10461, USA.

Capacitative calcium entry (CCE) through stores-operated Ca2+ channels is an absolute requirement for normal activation of T lymphocytes. Organic blockers/inhibitors of the channel(s) that carry the inward Ca2+ current (I(CRAC)) responsible for CCE are few. Here we show that capsaicin, the pungent ingredient of hot chili pepper, blocks receptor-stimulated Ca2+ entry in Jurkat T cells. Indo-1 measurements of intracellular calcium show that capsaicin blocks CCE without affecting release of inositol-1,4,5-trisphosphate-sensitive internal Ca2+ stores with an IC50 of 32 microM. Block of Ca2+ entry by capsaicin is identical whether CCE is evoked by T-cell receptor (TCR) stimulation, heterologous muscarinic M1 receptor stimulation, or via thapsigargin depletion of internal Ca2+ stores. Patch-clamp experiments show that capsaicin rapidly and reversibly blocks I(CRAC) with an identical dose response as seen with indo-1 measurements. The major voltage-gated K+ channel in Jurkat cells, Kv1.3, is also blocked by capsaicin. Although Kv1.3 block may contribute to reducing CCE by changes in membrane potential, block of I(CRAC) is the primary mechanism by which capsaicin reduces CCE. Capsaicin analogs capsazepine and resiniferatoxin also produce inhibition of CCE via block of I(CRAC). Upon application of capsaicin to Jurkat cells in culture we observed an inhibition of interleukin-2 (IL-2) production in response to TCR stimulation. The dose dependence of capsaicin's reduction of IL-2 was comparable with its block of I(CRAC), thereby illustrating the functional relevance of capsaicin's block of lymphocyte CCE. Thus, capsaicin and its numerous analogs may have potential use as immunomodulatory drugs and should be further investigated in models of inflammation and T-cell activation.
http://www.ncbi.nlm.nih.gov/pubmed/11561085?ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum
3 years antibiotics, 06/09 bilateral jug stents at C1, 05/11 ballooning of both jug valves, 07/12 stenting of renal vein, azygos & jug valve ballooning,
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