Persistent noncytopathic infection of normal human T lymphocytes with AIDS-associated retrovirus.

Infection of normal peripheral blood T cells by the acquired immune deficiency syndrome (AIDS)-associated retrovirus (ARV) was evaluated in long-term cultures of helper-inducer T cells (T4 cells). Cells that were inoculated with ARV and maintained in medium supplemented with interleukin-2 remained productively infected with this virus for more than 4 months in culture, although they showed no cytopathic effects characteristic of acute ARV infection. The presence of replicating virus was demonstrated by reverse transcriptase activity of culture fluids and by viral antigens and budding particles detected on cells by immunofluorescence and electron microscopy. Virus produced in these cultures remained infectious and could induce cytopathic effects and viral antigens in uninfected lymphoid cells. The finding that normal lymphocytes may be productively infected by an AIDS retrovirus in the absence of cell death suggests that a range of biologic effects may occur after infection in vivo.