  
Loss of effector function may explain high HIV load despite high CD8+ T cell count
Last Updated: 2001-04-16 18:28:34 EDT (Reuters Health)
WESTPORT, CT (Reuters Health) - Although most HIV-infected patients have sustained expansion of HIV-specific CD8 T cells, many of these cells appear to be nonfunctional, resulting in high viral burden, according to a report by European researchers.
Dr. Stefan Kostense, from Academic Medical Center, Amsterdam, the Netherlands, and colleagues used HLA-peptide complexes to enumerate HLA-A2-, B8- and B57-restricted CD8+ T cells directed against several HIV epitopes in 54 HIV-infected patients not receiving antiretroviral therapy.
HIV-specific tetramer+ cells were inversely correlated with viral load, among patients with high CD4+ T-cell counts. However, patients with CD4+ T-cell counts under 400 µL had high numbers of tetramer+ T cells along with a high viral load, according to the report in the March issue of European Journal of Immunology.
Furthermore, because the researchers found that only 4 of 13 patients with low frequencies of viruses had mutated epitopes, this lack of correlation between viral load and tetramer+ cells did not result from viral escape variants, they note.
In addition, the investigators measured the responsiveness to HIV peptide stimulation of CD8+ T cells from 15 patients. They found that the "proportion of IFN-gamma-producing tetramer+ cells correlated with AIDS-free survival and with T-cell maturation to the CD27-negative effector stage."
Dr. Kostense and colleagues conclude, "Our data indicate a qualitative and not a quantitative problem with HIV-specific CD8+ T cells, which may be related to impaired T-cell differentiation."
Eur J Immunol 2001;31:677-686.
-Westport Newsroom 203 319 2700
|
Copyright 2001 Reuters Limited. All rights reserved. Republication or redistribution of Reuters Limited content, including by framing or similar means, is expressly prohibited without prior written consent of Reuters Limited. Reuters Limited shall not be liable for any error or delays in the content, or for any actions taken in reliance thereon.
|
|
 Back To HIV Wellness Center
| 
