title: CD4 engagement by HIV-1 in TF-1 hematopoietic progenitor cells increases protein kinase C activity and reduces intracellular Ca2+ levels.
abstract: Starting from our previous observations that the HIV-1-mediated engagement of CD4 induced apoptotic death of TF-1 hematopoietic progenitor cells, in this study we evaluated PKC activity and intracellular Ca2+ levels in TF-1 cells treated with viable and heat-inactivated HIV-1 (strain IIIB) or anti-CD4 Leu3a monoclonal antibody (mAb). Both viable and heat-inactivated HIV-1 or anti-CD4 mAb, but not anti-human cytomegalovirus (HCMV) 66kD protein or anti-CD8 mAb induced a rapid (5-10 min) increase in PKC activity under both serum-containing and serum-free conditions. The same treatment also induced both a transient and a long-lasting (48 hours) decrease (p < 0.05) in intracellular Ca2+ levels in serum-containing cultures. We propose that the observed changes in PKC activity and intracellular Ca2+ levels might be involved in the HIV-1 mediated apoptosis of hematopoietic progenitor cells.
authors.affiliation: Institute of Microbiology, University of Bologna, Italy.
authors.forename: D
authors.initials: D
authors.lastname: Gibellini
authors.forename: G
authors.initials: G
authors.lastname: Zauli
authors.forename: M C
authors.initials: MC
authors.lastname: Re
authors.forename: G
authors.initials: G
authors.lastname: Furlini
authors.forename: S
authors.initials: S
authors.lastname: Lolli
authors.forename: P
authors.initials: P
authors.lastname: Borgatti
authors.forename: S
authors.initials: S
authors.lastname: Capitani
authors.forename: M
authors.initials: M
authors.lastname: La Placa
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology; D017209:Apoptosis; D015704:CD4 Antigens / Q000276:immunology / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D002460:Cell Line; D004789:Enzyme Activation; D015497:HIV-1 / Q000378:metabolism*; D006412:Hematopoietic Stem Cells / Q000378:metabolism / Q000382:microbiology*; D006801:Humans; D011493:Protein Kinase C / Q000378:metabolism*
chemical_list: D000911:Antibodies, Monoclonal; D015704:CD4 Antigens; D011493:Protein Kinase C; D002118:Calcium