Programmed death of T cells in human immunodeficiency virus infection. No correlation with progression to disease.
Programmed death of T cells has been proposed as one of the mechanisms by which HIV affects immune functions in stages of infection where the number of infected cells is low. Indeed, in HIV-infected individuals both CD4+ and CD8+ T cells are primed for programmed cell death, which can be enhanced by polyclonal stimulation. Here, we investigated programmed death of T cells in all stages of HIV infection, including acute infection. In individuals with primary infection the number of T cells dying due to apoptosis was much higher than in the asymptomatic phase of infection and paralleled increased numbers of CD8+ cells. In asymptomatic HIV-infected individuals, cells were dying in increased percentages compared with noninfected controls, although at much lower numbers than during acute infection. Death of T cells was not quantitatively correlated with CD4+ T cell numbers or appearance of more cytopathic, syncytium-inducing HIV variants. Analysis of the phenotype of cells undergoing apoptosis revealed that cell death was not confined to a specific T cell subset nor correlated with expression of certain T cell activation markers. Our results imply that the extent of programmed cell death of T cells in HIV infection does not correlate with progression to disease.
Meyaard
L
L
Department of Clinical Viro-Immunology, Central Laboratory of the Netherlands Red Cross Blood Transfusion Service, Amsterdam.
Otto
S A
SA
Keet
I P
IP
Roos
M T
MT
Miedema
F
F
D000938:Antigen-Presenting Cells / Q000502:physiology; D017209:Apoptosis; D016827:CD8 Antigens / Q000032:analysis; D002478:Cells, Cultured; D005260:Female; D015658:HIV Infections / Q000276:immunology*; D006801:Humans; D016130:Immunophenotyping; D007376:Interleukin-2 / Q000494:pharmacology; D007958:Leukocyte Count; D008297:Male; D013601:T-Lymphocytes / Q000276:immunology / Q000502:physiology*
D016827:CD8 Antigens; D007376:Interleukin-2