Prelim. Study - Suggested impaired immune tolerance for some

Lara · 03-23-2007, 06:14 AM

http://www.ncbi.nlm.nih.gov/entrez/q...=pubmed_docsum

Quote:

Biol Psychiatry. 2007 Feb 1;61(3):273-8. Epub 2006 Sep 25.

Decreased numbers of regulatory T cells suggest impaired immune tolerance in children with tourette syndrome: a preliminary study.

* Kawikova I,
* Leckman JF,
* Kronig H,
* Katsovich L,
* Bessen DE,
* Ghebremichael M,
* Bothwell AL.

Department of Immunobiology, Yale School of Medicine, New Haven, Connecticut 06520, USA.

BACKGROUND: Post-streptococcal autoimmune inflammation of basal ganglia was suggested to be an etiological factor in some cases of Tourette syndrome (TS). Since regulatory T (T reg) cells play a major role in preventing autoimmunity, we hypothesized that a defect in T reg cells may be present in children with TS. We also postulated that group A beta hemolytic streptococcal infections could promote autoimmune responses by releasing exotoxins (streptococcal pyrogenic exotoxins [SPE]).

METHODS: We analyzed peripheral blood of TS patients and healthy age-matched control subjects by fluorescence-activated cell sorting (FACS) on multiple occasions and determined the numbers of CD4(+)CD25(+)CD69(-) T reg cells. Further, we quantified the number of CD4(+) and CD8(+) lymphocytes with regard to Vbeta chains to which SPEs are known to bind.

RESULTS: A significant decrease in T reg cells was observed in patients with moderate to severe TS symptoms compared with healthy age-matched control children. A decrease in T reg cell number was also noted during symptom exacerbations in five out of six patients. Further, we found a significant decrease in numbers of CD8(+)Vbeta18(+) T cells in moderate to severe TS patients.

CONCLUSIONS: These data support our hypothesis that at least some TS patients may have a decreased capacity to inhibit autoreactive lymphocytes through a deficit in T reg cells. Interactions of host T cell immunity and microbial factors may also contribute to the pathogenesis of TS.

PMID: 16996487 [PubMed - indexed for MEDLINE]

doi:10.1016/j.biopsych.2006.06.012

Chemar · 03-23-2007, 09:03 AM

that is very interesting Lara

my son has never had strep, but he does have Crohn's Disease, which is autoimmune

Lara · 03-23-2007, 04:49 PM

I'm excited!!!

I think it's one of the most interesting things to see Yale come out with this after all these years. Some pieces are in the zigsaw are fitting together. I'm totally excited to read this extract. Hoping to hunt down the rest of it as soon as possible.

Edited to add: I guess I should clarify what I mean by being excited and why it's so interesting to me. It's because of my son's history, not my daughter's though. He had a totally different background medical history which included early diagnosis of Sydenham's Chorea (after suspected Rheumatic Fever) and some other things including later diagnosis of ASD. When I say interesting from Yale, I mean immune related. The outcome isn't going to make any difference to how my children are doing now, but it *may* answer a few of my questions I still have about a lot of things that have happened to him.

Laurensmom · 03-28-2007, 06:31 PM

Thanks for sharing.

Laurensmom · 03-28-2007, 06:47 PM

My daughter has TS and my husband is type 1 diabetic, so this is very interesting:

Quote:

Regulatory T cells (also known as suppressor T cells) are a specialized subpopulation of T cells that act to suppress activation of the immune system and thereby maintain immune system homeostasis and tolerance to self. The existence of a dedicated population of "suppressor" T cells was the subject of significant controversy among immunologists for many years. However, recent advances in the molecular characterization of this cell population have firmly established their existence and their critical role in the vertebrate immune system. Interest in regulatory T cells has been heightened by evidence from experimental mouse models demonstrating that the immunosuppressive potential of these cells can be harnessed therapeutically to treat autoimmune diseases and facilitate transplantation tolerance or specifically eliminated to potentiate cancer immunotherapy.

......

To function properly, the immune system must discriminate between self and non-self. When self/non-self discrimination fails, the immune system destroys cells and tissues of the body and as a result causes autoimmune diseases. Regulatory T cells actively suppress activation of the immune system and prevent pathological self-reactivity, i.e. autoimmune disease. The critical role regulatory T cells play within the immune system is evidenced by the severe autoimmune syndrome that results from a genetic deficiency in regulatory T cells.

......

The molecular mechanism by which regulatory T cells exert their suppressor/regulatory activity has not been definitively characterized and is the subject of intense research. In vitro experiments suggest that suppressive mechanism requires cell-to-cell contact with the cell being suppressed. However, the immunosuppressive cytokines TGF-beta and Interleukin 10 (IL-10), produced by Th3 and Tr1 cells respectively, have also been implicated in regulatory T cell function.

An important question in the field of immunology is how the immunosuppressive activity of regulatory T cells is modulated during the course of an ongoing immune response. While the immunosuppressive function of regulatory T cells prevents the development of autoimmune disease, it is not desirable during immune responses to infectious microorganisms. Current hypotheses suggest that upon encounter with infectious microorganisms the activity of regulatory T cells may be downregulated, either directly or indirectly, by other cells to facilitate elimination of the infection. Experimental evidence from mouse models suggests that some pathogens may have evolved to manipulate regulatory T cells to immunosuppress the host and so potentiate their own survival. For example, regulatory T cell activity has been reported to increase in several infectious contexts, such as retroviral infections and various parasitic infections including Leishmania and malaria.

http://en.wikipedia.org/wiki/Regulatory_T_cell

Tessa · 03-31-2007, 10:04 AM

Lara,

This is very exciting!!! It is encouraging that they are looking at these issues, as well. I do think it is a key puzzle piece for many, too. I thought Yale had pooh-poohed the strep connection.

Thanks for posting this. Reminds me of the old board and our discussions about this with dkw (aka) and FJ. I hope they are well.

Take care,
Tessa

Thread Tools
Show Printable Version Email this Page
Display Modes
Switch to Linear Mode Hybrid Mode Switch to Threaded Mode

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Anyone Else Visually Impaired Here And Use A Screen Reader?	Ripplegirl99	Computers and Technology	4	03-03-2007 03:56 PM
Impaired vision due to possible brain damage	George Edwards	General Health Conditions & Rare Disorders	0	02-11-2007 11:26 PM
Immune support - Immune defense against disease with several subdivisions.	nutri	General Health Conditions & Rare Disorders	2	02-06-2007 12:33 PM

Site Navigation

NeuroTalk Online Support Groups

Prelim. Study - Suggested impaired immune tolerance for some

NeuroTalk Forums