HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1 TAT PROTEIN PROTECTS LYMPHOID, EPITHELIAL, AND NEURONAL CELL-LINES FROM DEATH BY APOPTOSIS

We report here that the tat gene product of human immunodeficiency vir us type 1 was able to protect lymphoblastoid (Jurkat), epithelial (293 ) and neuronal (PC12) cell lines from apoptotic death induced by serum withdrawal. The rescue from apoptosis by Tat was reflected by an incr eased expression of Bcl-2 protein in tat-positive Jurkat cells with re spect to mock-transfected Jurkat cells after 3-6 days of serum-free cu ltures. We propose that the ability of the regulatory human immunodefi ciency virus type 1 Tat protein to suppress apoptosis might have impor tant implications in understanding the pathogenesis of frequent neopla stic disorders observed in human immunodeficiency virus type 1-seropos itive individuals.