IL-16 represses HIV-1 promoter activity.
IL-16 is produced by CD8+ lymphocytes and has been reported to inhibit HIV-1 and SIV replication in infected PBMCs. CD4 serves as a receptor for the secreted form of IL-16, and IL-16 binding to CD4 induces signal transduction, which affects the activation state of the cell. We hypothesized, therefore, that the effect of IL-16 on HIV-1 replication might occur at the level of virus expression. In transient transfection studies with HIV-1 LTR-reporter gene constructs we found that pretreatment of CD4+ lymphoid cells with recombinant IL-16 repressed HIV-1 promoter activity up to 60-fold, preventing both PMA and Tat activation. This effect of IL-16 required sequences contained within the core enhancer, but was not simply due to the down-regulation of transcription factors binding to this element.
Maciaszek
J W
JW
The Program in Virology and Immunology, University of Massachusetts Medical Center, Worcester 01605, USA.
Parada
N A
NA
Cruikshank
W W
WW
Center
D M
DM
Kornfeld
H
H
Viglianti
G A
GA
D015536:Down-Regulation / Q000187:drug effects*; D015696:Gene Products, tat / Q000037:antagonists & inhibitors / Q000494:pharmacology; D016325:HIV Long Terminal Repeat / Q000187:drug effects*; D015497:HIV-1 / Q000187:drug effects*; D006801:Humans; D019410:Interleukin-16 / Q000494:pharmacology*; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000494:pharmacology; D014775:Virus Activation / Q000187:drug effects; D054322:tat Gene Products, Human Immunodeficiency Virus
D015696:Gene Products, tat; D019410:Interleukin-16; D016328:NF-kappa B; D054322:tat Gene Products, Human Immunodeficiency Virus