'CD4(+) T cell dysfunction in HIV-1 infection is associated with increased CTLA-4 and TGF-beta expression. In this study we described a population of TGF-beta-positive CD4(+) T cells with multiple HIV specificities,' researchers in the United States report (see also HIV/AIDS).
'These HIV-specific TGF-beta-positive CD4(+) T cells did not display the immunophenotypic patterns traditionally attributed to regulatory CD4(+) T cells. TGF-beta-positive CD4(+) T cells were FOXP3 negative, CD25 negative, and displayed a heterogeneous surface expression of CD127. We also examined one potential mechanism for regulating TGF-beta expression by HIV-specific CD4(+) T cells. Blocking of the TGF-beta receptor II led to increased HIV-specific IFN-gamma-positive CD4(+) and CD8(+) T cell responses. Interestingly, HIV-specific TGF-beta-positive CD4(+) T cells did not substantially express CTLA-4. Nevertheless, CTLA-4 blockade resulted in a significant decrease in HIV-specific TGF-beta-positive CD4(+) T cell responses, and a concomitant increase in HIV-specific IFN-gamma-positive CD4(+) T cell responses,' wrote M. Elrefaei and colleagues.
The researchers concluded: 'Our study proposes a mechanism by which HIV-specific TGF-beta production may be regulated by CTLA-4 engagement.'
Elrefaei and colleagues published their study in AIDS Research and Human Retroviruses (HIV-Specific TGF-beta-Positive CD4(+) T Cells Do Not Express Regulatory Surface Markers and Are Regulated by CTLA-4. AIDS Research and Human Retroviruses, 2010;26(3):329-337).
For additional information, contact M. Elrefaei, California Dept. of Public Health, 850 Marina Bay Pkwy VRDL, Richmond, CA 94804, USA.
Publisher contact information for the journal AIDS Research and Human Retroviruses is: Mary Ann Liebert Inc., 140 Huguenot Street, 3RD FL, New Rochelle, NY 10801, USA.
Keywords: City:Richmond, State:CA, Country:United States, HIV Infections, HIV/AIDS, Primate Lentiviruses, RNA Viruses, Retroviridae, Vertebrate Viruses, Viral Sexually Transmitted Diseases
This article was prepared by AIDS Vaccine Week editors from staff and other reports. Copyright 2010, AIDS Vaccine Week via NewsRx.com.
