HLA-G and transplant rejection

[pelagia]

I couldn't find anything on the IHD site about this, so here's a question.

Is anyone (Stauff?) familiar with the current research on HLA-G regarding its effects on immune system regulation relative to kidney (and liver) transplant recipients?

I am finding recent papers such as the one excerpted below which suggest that levels of HLA-G in the bloodstream may be useful for predicting both acute and chronic rejection.  I also found statements in the literature that therapies to modulate HLA-G production might lead to better immnuosuppression in transplant recipients.  Seems that more may be better, but also that more research is needed.  Most of the papers are very recent and not available without a subscription.  I can only get to the abstracts.

From: Kaneku, H. Detection of soluble HLA-G and its correlation with kidney transplant outcome. Clinical Transpl 2006: 447-54

"We showed a protective effect of soluble HLA-G in sera of kidney transplant patients, confirming the statement that sHLA-G plays a role in the regulation of the immune system, leading to a better acceptance of the graft. Our results also suggest that determining sHLA-G concentration in serum could help to correlate in a better way the expression of this molecule and its protective effect since it has been demonstrated a concentration-dependent effect. The relationship between the production of HLA antibodies and the expression of sHLA-G is not clear, however, since there is not much information regarding this. Further studies are required in order to have more sources for better conclusions and to keep describing precisely the properties of this molecule."

[pelagia]

   just thought I'd bump this and try one more time to see if anyone knows anything about this research.

thanks!

[okarol]

Found this, not sure it's what you're looking for:

Immune Molecule Key to Preventing Organ Rejection

Date:6/23/2008

Measuring HLA-G dimer may identify patients who need little, if any, immune suppression

MONDAY, June 23 (HealthDay News) -- An immune molecule called HLA-G dimer plays a powerful role in preventing the immune system from rejecting transplanted organs and tissue, Medical College of Georgia researchers say.

They found that HLA-G helped prolong skin graft survival in mice and are currently studying whether this molecule is at work in kidney transplant patients who don't experience organ rejection.

"This is a molecule with huge potential to regulate immune response," Dr. Anatolij Horuzsko, a reproductive immunologist at the Medical College of Georgia Center for Molecular Chaperone/Radiobiology and Cancer Virology, said in a prepared statement.

He and his colleagues found 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," said Horuzsko, corresponding author of the study, which was published online in the journal Proceedings of the National Academy of Sciences.

The researchers looked at the resulting strong signal in culture and then assessed its impact on skin graft survival in mice.

Horuzsko and colleagues believe HLA-G dimer's action can be boosted in order to suppress immune activity in people with organ transplants and autoimmune diseases, and turned down in order to increase immune system activity against tumors. Measuring levels of HLA-G dimer may also help doctors identify transplant patients who require little, if any, immune system suppression.

More information

The MedlinePlus Medical Encyclopedia has more about transplant rejection. http://www.nlm.nih.gov/medlineplus/ency/article/000815.htm

http://www.bio-medicine.org/medicine-news-1/Immune-Molecule-Key-to-Preventing-Organ-Rejection-22551-1/

[pelagia]

Thanks Okarol.  I hadn't found this article.  This seems like a very exciting area of research but there doesn't seem to be much information available.