Navigation Links
Genes determine the capacity to fight HIV in early stages

The capacity of an individual's immune system to control HIV infection appears to depend on both the specific versions of key immune-system molecules// called HLA Class I that have been inherited, as well as on the fragments of viral protein those molecules display to the T lymphocytes that usually destroy infected cells. In a report in the November issue of PLOS Medicine, researchers from the Partners AIDS Research Center at Massachusetts General Hospital (PARC/MGH) report that specific HLA Class I/HIV viral fragment combinations are associated with a more powerful antiviral response, findings that may help develop vaccines against HIV. .

"We found that only a limited number of viral protein fragments from HIV-1 are targeted by the immune system in early infection and that the versions of HLA Class I previously associated with slower HIV-1 disease progression also contribute more to this initial antiviral immune response," says Marcus Altfeld, MD, PhD, of PARC/MGH, the paper's lead author. .

An essential aspect of the immune response involves educating T cells to recognize pathogens or other "non-self" proteins. This is done by means of human leukocyte antigen (HLA) receptors that sit on the surface of virtually every cell. Immune system cells that ingest bacteria or parasites digest those pathogens and display protein fragments on their surface membranes via HLA Class II proteins. Virally infected cells display viral proteins on HLA Class I molecules, which activate the CD8 cytotoxic T lymphocytes that usually destroy infected cells. Although the CD8 response against HIV is ultimately ineffective in protecting infection, several studies have suggested that it plays a key role in determining how quickly the disease progresses after initial infection. .

HLA – also called major histocompatibility complex (MHC) – proteins are also the primary markers of tissues as "self." Unique to each individual, these are the factors that need to be match ed as closely as possible in organ transplants, with perfect matches only possible between identical twins. Some studies have found that HIV patients with particular versions of HLA may be better able to control viral levels, but the diversity of HLA molecules – each person may have up to six different varieties of Class I proteins – has made investigating the role of HLA type in HIV infection challenging.

The current study was designed to determine the contribution of both HLA Class I and the particular viral fragments displayed on those molecules to the activation of HIV-specific CD8 cells. The researchers analyzed blood samples from more than 100 people recently infected with HIV, first determining their specific HLA types by DNA analysis. Then they focused on 173 HIV protein fragments known to bind to those HLA types to see if particular peptides were more powerful in activating the HIV-specific CD8 response. The researchers found that, for many varieties of HLA, only a few HIV protein fragments were responsible for the activation of CD8 T cells early in infection. In addition, the same HLA types that had been previously identified in people who stay healthy for a longer period of time after initial infection were associated with a more powerful early-stage HIV-specific CD8 activity. .

"While we can't say this for sure right now, it is looking like both the HLA Class I molecule and the specific viral sequences being displayed contribute to the strength of immune response against primary HIV infection," says Altfeld. "In addition, the combination of Class I molecules that an individual expresses, something that is genetically determined, seems to have a significant impact on the specificity and strength of that response. .

"Identifying the HIV epitopes [viral fragments] that are particularly good at priming an early T cell response may be important to vaccine design, and the impact of an individual's genetic HLA Class I backg round implies that a successful vaccine would have to overcome genetic factors associated with a less protective response," he adds. Altfeld is an associate professor of Medicine at Harvard Medical School. He and his colleagues are working on a follow-up study with samples from 500 individuals to further investigate the impact of HLA Class I on the control of HIV replication. .

source: EurekAlert

Source-Eurekalert
RM
'"/>




Related medicine news :

1. New Way to "See" Genes, Evaluate Effectiveness of Gene Therapies Discovered
2. Genes for lung disease
3. Genesis of SUPAC
4. Genes for Vision discovered
5. Genes Found To Help Leukemia Treatment
6. Cardiac Valve Disease Linked To Genes
7. Genes Linked To Cigarette Addiction
8. Genes from saliva may predict oral and breast cancer
9. Genes More Important Than Exercise for Bad Cholesterol
10. Genes responsible for social behavior of us
11. Genes to Extend Longevity Discovered
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:6/26/2016)... Creek, Michigan (PRWEB) , ... June 26, 2016 , ... ... joined as sponsor of the 2016 Cereal Festival and World’s Longest Breakfast Table in ... in honor of the city’s history as home to some of the world’s leading ...
(Date:6/26/2016)... (PRWEB) , ... June 26, 2016 , ... ... fertility once they have been diagnosed with endometriosis. These women need a treatment ... also require a comprehensive approach that can help for preservation of fertility and ...
(Date:6/25/2016)... ... ... "With 30 hand-drawn hand gesture animations, FCPX users can easily customize each ... Film Studios. , ProHand Cartoon’s package transforms over 1,300 hand-drawn pictures into hand ... select a ProHand generator and drag it above media or text in the Final ...
(Date:6/25/2016)... (PRWEB) , ... June 25, 2016 , ... On Friday, ... presented a Bronze Wellness at Work award to iHire in recognition of their exemplary ... part of the 7th annual Maryland Workplace Health & Wellness Symposium at the BWI ...
(Date:6/24/2016)... ... ... June 19, 2016 is World Sickle Cell Observance Day. In an effort to ... treatments, Serenity Recovery Center of Marne, Michigan, has issued a pain management ... (SCD) is a disorder of the red blood cells, which can cause episodes of ...
Breaking Medicine News(10 mins):
(Date:6/23/2016)... , June 23, 2016 Roche (SIX: RO, ... clearance for its Elecsys BRAHMS PCT (procalcitonin) assay as ... or septic shock. With this clearance, Roche is the ... fully integrated solution for sepsis risk assessment and management. ... bacterial infection and PCT levels in blood can aid ...
(Date:6/23/2016)... , June 23, 2016 Research ... Pharma News Issue 52" report to their offering. ... in influenza treatment creates a favourable commercial environment for MedImmune ... growing patient base that will serve to drive considerable growth ... vaccine would serve to cap sales considerably, but development is ...
(Date:6/23/2016)... PARK RIDGE, Ill. and INDIANAPOLIS ... caliber of students receiving a Lilly Diabetes Tomorrow,s Leaders ... hands. The 2016 scholarship winners, announced today online at ... refused to let type 1 diabetes stand in the ... Lilly Diabetes has supported the Foundation,s scholarship program since ...
Breaking Medicine Technology: