Progressive B cell apoptosis and expression of Fas ligand during human immunodeficiency virus type 1 infection.
HIV-1 infection causes functional defects in T cells. It also leads to a progressive reduction in numbers of such cells and both CD4+ and CD8+ cells have been reported to undergo apoptosis in culture. A corresponding reduction in B cells has not been described, but these cells are also functionally altered, with reports of polyclonal activation and hyporesponsiveness to antigenic and mitogenic stimuli. Here we investigated B cells from HIV-1-seropositive individuals and found that these cells, which are not the target for virus infection, died of apoptosis on culturing. We could also confirm previous findings that CD4+ cells from HIV-1-infected individuals undergo apoptosis in culture. Apoptosis of both B cells and CD4+ cells correlated inversely with CD4 cell counts. B cells from HIV-1-infected individuals were found to express Fas ligand, and the expression of this protein correlated with the levels of apoptosis in the same cells. Non-B cells, on the other hand, expressed increased levels of Fas but low levels of Fas ligand. These results are in line with suggestions that the Fas/Fas ligand pathway may trigger the increased levels of apoptosis observed in cells from HIV-1-infected individuals.
Samuelsson
A
A
Microbiology and Tumor Biology Center, Karolinska Institute, Stockholm, Sweden.
Sönnerborg
A
A
Heuts
N
N
Cöster
J
J
Chiodi
F
F
D000328:Adult; D018941:Antigens, CD19 / Q000276:immunology; D017209:Apoptosis; D001402:B-Lymphocytes / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D002478:Cells, Cultured; D053222:Fas Ligand Protein; D005434:Flow Cytometry; D015658:HIV Infections / Q000276:immunology*; D006801:Humans; D008024:Ligands; D008562:Membrane Glycoproteins / Q000096:biosynthesis*; D008875:Middle Aged; D019014:fas Receptor / Q000096:biosynthesis
D018941:Antigens, CD19; C505661:FASLG protein, human; D053222:Fas Ligand Protein; D008024:Ligands; D008562:Membrane Glycoproteins; D019014:fas Receptor