THE HIV-1 GP120 CAUSES ULTRASTRUCTURAL-CHANGES TYPICAL OF APOPTOSIS IN THE RAT CEREBRAL-CORTEX

WE used transmission electron microscopy (TEM) and terminal deoxynucle otidyl transferase (TdT)-mediated dUTP-biotin nick end-labelling (TUNE L) techniques to study the neuropathological effects of intracerebrove ntricular (i.c.v.) injection of recombinant HIV-1 gp 120 in rats. In b rain cortical tissue sections from rats treated with a single daily do se of gp120 (100 ng day(-1) for 7 or 14 consecutive days) TEM analysis showed chromatin compaction and marginalization along the inner surfa ce of the nuclear envelope followed by masses of condensed chromatin, ultrastructural signs demonstrating the occurrence of apoptotic cell d eath. These effects were paralleled by in situ DNA fragmentation, as r evealed by application of TUNEL technique to cryostat brain tissue sec tions from rats treated likewise with the viral coat protein. In no in stance was apoptosis seen in the brain cortex of control rats. The pre sent data demonstrate that gp120 given i.c.v. produces apoptosis in th e neocortex of rats.