Fas/FasL interaction is not involved in apoptosis of activated CD4+ T cells upon HIV-1 infection in vitro.
In HIV-1-infected individuals, Fas expression and Fas/FasL-mediated apoptosis of mature T cells are known to increase compared with those in normal individuals. To elucidate a relation between acute HIV-1 infection and the regulation of Fas/FasL system upon T-cell activation, resting CD4+ T cells were acutely infected or uninfected with HIV-1 and subsequently activated by phorbol myristate acetate and ionomycin (PMA/IM). Four days after infection, when HIV-1 env gp120 is expressed in more than one half of activated T cells, Fas/FasL expression was analyzed by flow cytometry, and apoptosis-inducing activity of these activated primary CD4+ T cells on Fas+ Jurkat cells was examined. The level of Fas or FasL expression was not altered during acute HIV-1 infection. The enhanced apoptosis-inducing activity upon HIV-1 infection was observed in some individuals, but its activity was not Fas/FasL-mediated. These results indicate that HIV-1 infection is not necessarily associated with either upregulation of Fas/FasL expression or Fas/FasL-mediated apoptosis.
Yagi
T
T
Department of Immunology, AIDS Research Center, National Institute of Infectious Disease, Tokyo, Japan.
Sugimoto
A
A
Tanaka
M
M
Nagata
S
S
Yasuda
S
S
Yagita
H
H
Kuriyama
T
T
Takemori
T
T
Tsunetsugu-Yokota
Y
Y
D000911:Antibodies, Monoclonal / Q000276:immunology; D000954:Antigens, Surface / Q000502:physiology; D017209:Apoptosis / Q000502:physiology*; D015496:CD4-Positive T-Lymphocytes / Q000502:physiology / Q000821:virology*; D002460:Cell Line; D002478:Cells, Cultured; D053938:DNA Fragmentation / Q000502:physiology; D053222:Fas Ligand Protein; D005434:Flow Cytometry; D015699:HIV Envelope Protein gp120 / Q000032:analysis / Q000276:immunology; D015497:HIV-1 / Q000502:physiology*; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000502:physiology; D008024:Ligands; D008213:Lymphocyte Activation; D008562:Membrane Glycoproteins / Q000096:biosynthesis / Q000502:physiology*; D015375:Receptors, Interleukin-2 / Q000096:biosynthesis; D015854:Up-Regulation; D019014:fas Receptor / Q000096:biosynthesis / Q000502:physiology*
D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; C505661:FASLG protein, human; D053222:Fas Ligand Protein; D015699:HIV Envelope Protein gp120; D008024:Ligands; D008562:Membrane Glycoproteins; D015375:Receptors, Interleukin-2; D019014:fas Receptor