Inhibition of HIV replication by CD8+ T cells correlates with CD4 counts and clinical stage of disease.
We sought to evaluate the relationship of CD8+ T cell-mediated inhibition of autologous HIV replication in vitro to disease stage in HIV+ individuals. Depletion of CD8+ T cells from peripheral blood lymphocytes of 16 HIV+ subjects increased the percentage of virus-producing cultures from 56% to 81%. CD4+ T cells were purified from 52 HIV+ individuals and cultured alone or in the presence of autologous CD8+ T cells. In 13 (25%) subjects HIV replication was only detected in the absence of CD8+ T cells (inhibition positive); in 26 (50%) viral replication occurred both in the absence and presence of CD8+ cells (inhibition negative). In the remaining 13 (25%) subjects, CD8+ T cell-mediated inhibitory activity could not be evaluated because stimulation of their purified CD4+ T cells did not result in p24 production. In some virus culture-negative individuals, the inability to demonstrate HIV replication was due to the presence of low numbers of CD8+ T cells that co-purified with CD4+ T cells. Detection of inhibitory CD8+ T cells was associated with significantly higher CD4 counts and better clinical status compared with inhibition-negative subjects. These results demonstrate that CD8+ T cell-mediated inhibition of HIV replication correlates with disease stage, and thus may play a role in preventing disease progression. CD8+ T cells did not inhibit autologous HIV replication across a semipermeable membrane. Further, the ability of CD8+ T cells to prevent HIV replication did not correlate with lysis of autologous CD4+ T cells. Thus, CD8+ T cells inhibited autologous HIV replication in vitro through a contact-mediated non-lytic mechanism.
Gómez
A M
AM
Department of Pathology, McMaster University Health Sciences Center, Hamilton, Ontario, Canada.
Smaill
F M
FM
Rosenthal
K L
KL
D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D016827:CD8 Antigens / Q000378:metabolism*; D002450:Cell Communication; D003208:Concanavalin A / Q000494:pharmacology; D016655:HIV Core Protein p24 / Q000096:biosynthesis; D015658:HIV Infections / Q000097:blood / Q000276:immunology* / Q000382:microbiology*; D054303:HIV Reverse Transcriptase; D015497:HIV-1 / Q000276:immunology* / Q000502:physiology*; D006801:Humans; D066298:In Vitro Techniques; D007958:Leukocyte Count; D008213:Lymphocyte Activation; D012194:RNA-Directed DNA Polymerase / Q000378:metabolism; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D014779:Virus Replication
D016827:CD8 Antigens; D016655:HIV Core Protein p24; D003208:Concanavalin A; D054303:HIV Reverse Transcriptase; D012194:RNA-Directed DNA Polymerase