Platelet-activating factor activates HIV promoter in transfected SH-SY5Y neuroblastoma cells and MOLT-4 T lymphocytes.
Transfected gene constructs comprising the long terminal repeat (LTR) sequence of the human immunodeficiency virus (HIV) genome spliced to an assayable reporter gene have made possible the evaluation of a lipid mediator, platelet-activating factor (PAF), as a potential HIV transcriptional regulatory molecule. We assessed the activation of the HIV LTR promoter sequence linked to the chloramphenicol acetyltransferase (CAT) reporter gene (HIV-CAT) by PAF in both a human neural (SH-SY5Y neuroblastoma) and a human leukocytic (MOLT-4 T-lymphocyte) cell line. PAF activated expression of the HIV-CAT construct in both the SH-SY5Y and MOLT-4 T-cell lines. PAF-induced CAT activity was approximately six to seven times higher in the SH-SY5Y cells than in the MOLT-4 cells. Preincubation of cells with the specific PAF antagonist BN 52021 completely inhibited CAT expression in both cell lines. The biologically inactive PAF precursor lyso-PAF did not activate CAT expression. Assays for CAT mRNA demonstrated an increase after PAF treatment, an effect that was completely inhibited by BN 52021, and which was not elicited by lyso-PAF. These results show that PAF represents a potential cellular mediator evoking the expression of the HIV genome.
Squinto
S P
SP
Department of Biochemistry and Molecular Biology, Louisiana State University Medical Center, New Orleans 70112.
Braquet
P
P
Block
A L
AL
Bazan
N G
NG
D000163:Acquired Immunodeficiency Syndrome / Q000188:drug therapy / Q000235:genetics; D000818:Animals; D015195:Drug Design; D015967:Gene Expression Regulation, Viral / Q000187:drug effects*; D005814:Genes, Viral / Q000187:drug effects*; D006678:HIV / Q000187:drug effects*; D006801:Humans; D015459:Leukemia-Lymphoma, Adult T-Cell / Q000473:pathology*; D009447:Neuroblastoma / Q000473:pathology*; D010972:Platelet Activating Factor / Q000494:pharmacology*; D011401:Promoter Regions, Genetic / Q000187:drug effects*; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D012091:Repetitive Sequences, Nucleic Acid; D013268:Stimulation, Chemical; D013601:T-Lymphocytes / Q000187:drug effects / Q000382:microbiology; D014162:Transfection; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000382:microbiology
D010972:Platelet Activating Factor; D011993:Recombinant Fusion Proteins