Leu-3- cells that survive infection with the acquired immune deficiency syndrome (AIDS) retrovirus can be induced with IUdR to express infectious virus. A cellular clone (8E5), isolated by limiting dilution of a mass culture of survivor cells, was found to contain a single, integrated provirus that was constitutively expressed. Although IUdR treatment of 8E5 cells failed to induce infectious virus, cocultivation with Leu-3+ cells generated the characteristic syncytia associated with acute AIDS retrovirus infection. The single integrated copy of proviral DNA directs the synthesis of all major viral structural proteins except p64, as monitored by immunoblotting. The relationship of the 8E5 clone to viral latency and persistence is discussed.