Multifunctional activity of recombinant p14 on lymphoid cell cultures

Some effects of recombinant p14, a protein encoded by the tat gene of immun odeficiency virus type 1 (HIV-1), were investigated on T lymphocytic cell c ultures. Ln particular, we detected p14 adsorption to cells, the rate of ce ll replication, the expression of fibronectin (FN) and its receptor (FNR) a nd of cell surface CD4 antigen in HIV-l-infected or uninfected MT-4 and H9 cells, treated with p14. Moreover, we evaluated the proportion of apoptotic cells in uninfected and chronically infected H9 cells in the presence of p 14 and the modulation of interferon (IFN) production induced by p14 in PBMC of healthy subjects. The results obtained demonstrate that p14 exerts mult ifunctional activities on HIV-1 infected and uninfected cells. In particula r, this protein interacts in a specific manner with cell surface, especiall y with that of infected cells, and enhances the expression of FN and FNR bu t nor that of the CD4 lymphocyte antigen. Moreover, p14 increases cell repl ication IFN production and can exert a slight modulation of apoptosis. We a lso propose a model to explain a possible role in HIV-1 infection of the ef fects of exogenous p14.