Interferon induction by cell-cell interaction of HIV-infected monocytes/macrophages with lymphocytes.

An in vitro model of interferon (IFN) induction in HIV infection was established. IFN are induced by a cooperative mechanism, involving monocytes/macrophages (M/M) as well as lymphocytes. M/M non-lytically infected with HTLV-IIIB did not produce IFN, but were able to induce high titres of IFN activity when cocultured with peripheral blood lymphocytes, cell-cell contact being required. IFN alpha as well as IFN gamma were induced, as shown by neutralization with specific antisera. The antiviral activity of HIV-induced IFN was shown by infectivity reduction assays, and the immune-modulating capacity was demonstrated by activation of M/M leading to neopterin release.