Direct relationship between suppression of virus-specific immunity and emergence of cytomegalovirus disease in simian AIDS.

Although opportunistic infections like cytomegalovirus (CMV) are common sequelae of end-stage AIDS, the immune events leading to CMV reactivation in human immunodeficiency virus (HIV)-infected individuals are not well defined. The role of cellular and humoral CMV-specific immune responses in immune control of latent CMV infection was evaluated prospectively in a cohort of 11 simian immunodeficiency virus (SIV)-infected CMV-seropositive rhesus macaques, 6 of whom had histologic evidence of CMV disease at death. Macaques with CMV disease differed from macaques without CMV disease in having significantly higher levels of plasma SIV RNA and CMV DNA and significantly lower titers of anti-CMV binding antibodies (Abs) at the time of death.

Decreased frequency of cytomegalovirus (CMV)-specific CD4+ T lymphocytes in simian immunodeficiency virus-infected rhesus macaques: inverse relationship with CMV viremia.

The frequency of cytomegalovirus (CMV)-specific CD4+ T lymphocytes was determined in CMV-seropositive rhesus macaques with or without simian immunodeficiency virus (SIV) infection by using the sensitive assays of intracellular cytokine staining and gamma interferon ELISPOT. Both techniques yielded 3- to 1,000-fold-higher frequencies of CMV-specific CD4+ T lymphocytes than traditional proliferative limiting dilution assays. The median frequency of CMV-specific CD4+ T lymphocytes in 23 CMV-seropositive SIV-negative macaques was 0.