Design: Five HIV-infected patients, who were highly adherent to antiretroviral treatment, were selected on the basis of long-term undetectable plasma viral RNA on unmodified HAART. To investigate the antigen specificities of infected memory CD4 T cells, we examined the capacity of recall antigens, including HIV antigens, to induce virus production by peripheral blood mononuclear cells (PBMC).
Methods: To quantify CD4 T cells infected by replication-competent virus, and to determine their antigen specificities, we used a limited dilution-based culture assay. CD8 T cell-depleted PBMC at several cell densities were activated by using Tuberculin purified protein derivative, Cytomegalovirus, or HIV-1 p24 with and without HIV-1 Nef.
Results: We found that the pool of infected CD4 T cells includes HIV-specific cells with apparent frequencies between 5- and 100-fold higher than those of the common specificities for Cytomegalovirus or Tuberculin.
Conclusion: Our findings suggest that a significant proportion of replication-competent HIV-infected CD4 T cells in these patients are memory cells directed against HIV determinants. This may provide a rationale for the therapeutic use of recombinant HIV antigens to reduce the pool of HIV-reservoir cells. [A. Demoustier et al.; AIDS, 2002;16:1749-1754.]
Back to the October 2002 issue of IAPAC Monthly.