HIV infection induces the loss of immunological control of HIV replication but the mechanism involved in altering HIV-specific CD4+ T-cell responses remains unresolved. In May 2 Nature, Daniel Douek and colleagues from National Institutes of Health, Maryland, USA show that the virus replicates unchecked because HIV preferentially infects HIV-specific CD4+ T cells (Nature 2002, 417:95-98).
Douek et al. observed that HIV-specific memory CD4+ T cells in infected individuals contain more HIV viral DNA than other memory CD4+ T cells, at all stages of HIV disease. In addition, following viral rebound during interruption of antiretroviral therapy, the frequency of HIV viral DNA in the HIV-specific pool of memory CD4+ T cells increases to a greater extent than in memory CD4+ T cells of other specificities.
"In any event, this preferential but low-frequency infection of HIV-specific and other activated T cells may represent an evolutionary adaptation that enables persistent infection in an ...