[Pathological cleavage of human immunodeficiency virus gp160 protein in infected cells as a probable factor for infection becoming chronic].

The synthesis of HIV-1 (IIIb isolate) structural protein in chronically (CI) and acutely infected (AI) MT4 cells was studied. During long-term cultivation the CI system was characterized by high involvement of the cells into infection (up to 100%), high level of virus-specific protein synthesis, moderate virus yield, but absence of any virus-induced cytopathic effects and normal growth potential of infected cells. AI cells demonstrated a similar level of synthesis of virus specific proteins, higher virus yield, and rapid progression of cytopathicity followed by total cell death. Most of the HIV gp160 protein molecules undergo rapid cleavage in the region between the point of conventional cleavage and the transmembrane domain, being removed from the physiologically competent pool, but a small portion of gp160s undergo apparently normal intracellular development. According to our data, the two HIV variants (normal and defective) persist in CI system and pathological cleavage of defective virus gp160 protein results most probably in chronization of infection.