BACKGROUNDHIV-1 infected and immune-activated macrophages and microglia secrete neurotoxins, such as tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β), which play major role in the neuronal death. It has been shown that different HIV-1 variants have varying abilities to elicit secretion of TNF-α by peripheral blood mononuclear cell (PBMC); however, whether the difference of gp120 gene could affect the secretion of TNF-α and IL-1β by glial cells is unknown. The aim of this study was to explore the association between gene diversity and induction of neurotoxic cytokines.

METHODSIn this study, we constructed retroviral vectors MSCV-IRES-GFP/gp120 using HIV-1 gp120 genes isolated from four different tissues of one patient who died of AIDS dementia complex (ADC). Recombinant retroviruses produced by cotransfection of MSCV-IRES-GFP/gp120, pCMV-VSV-G and pUMVC into 293T cells were collected and added into U87 glial cells. Concentrations of TNF-α and IL-1β secreted by transduced U87 cells were assayed with ELISA separately.

RESULTSThe four HIV-1 gp120 were in the different branch of the neighbor-joining tree. Compared to the pMIG retrovirus (gp120-negative) or U87 cells, all the gp120-positive recombinant retroviruses induced more TNF-α (P < 0.01) and IL-1β (P < 0.01). In addition, compared with the L/MIG retrovirus, all the three brain gp120-positive recombinant retroviruses induced less TNF-α (P < 0.01) and IL-1β (P < 0.01).

CONCLUSIONSHIV-1 gp120 could induce U87 cells secret more TNF-α and IL-1β again. The more important is that difference of HIV-1 gp120, especially cell-tropism may account for the different ability in eliciting secretion of TNF-α and IL-1β, which might supply a novel idea helping understand the pathogenesis of ADC.