Quantitation of HIV-1-Specific Cytotoxic T Lymphocytes and Plasma Load of Viral RNA

TLDR

Although CTLs are believed to control HIV‑1 infection, a direct relationship between CTL activity and plasma RNA viral load had not been demonstrated. Human leukocyte antigen–peptide tetrameric complexes enable direct ex vivo quantitation of circulating CTLs. Using these complexes, the study found a significant inverse correlation between HIV‑specific CTL frequency and plasma RNA viral load, but no link between infected‑cell clearance rate and CTL frequency, supporting a key role for CTLs in controlling HIV infection and indicating a substantial cytopathic effect of the virus in vivo.

Abstract

Although cytotoxic T lymphocytes (CTLs) are thought to be involved in the control of human immunodeficiency virus–type 1 (HIV-1) infection, it has not been possible to demonstrate a direct relation between CTL activity and plasma RNA viral load. Human leukocyte antigen–peptide tetrameric complexes offer a specific means to directly quantitate circulating CTLs ex vivo. With the use of the tetrameric complexes, a significant inverse correlation was observed between HIV-specific CTL frequency and plasma RNA viral load. In contrast, no significant association was detected between the clearance rate of productively infected cells and frequency of HIV-specific CTLs. These data are consistent with a significant role for HIV-specific CTLs in the control of HIV infection and suggest a considerable cytopathic effect of the virus in vivo.