Single-stranded 3H-DNA probes complementary to the RNA of Rauscher murine leukemia virus and of simian sarcoma virus were prepared using techniques that permitted complete transcription of the viral genome of each virus. These probes were used in DNA-DNA hybridization studies with the cellular DNA from uncultured specimens of spleens and placentas of patients with systemic lupus erythematosus (SLE). No proviral DNA sequences related to these viruses were detected in these tissues. The results presented here do not support previously reported antigenic data implicating type-C oncornavirus infection of these organs in SLE. Type-C oncornaviruses, which belong to the family Retraviridae, consist of a ribonucleoproteifl core enclosed in a lipoprotein envelope that has surface projections of glycoproteins (1-3). The core contains the RNA genome and an RNA-directed-DNA-polymerase (4,5). The presence of this reverse transcriptase enables these viruses to transcribe DNA copies that become integrated into the DNA of the infected host cell (6). Various strains of type-C oncornaviruses are widespread among species of the animal kingdom and there are a number of reports implicating their presence in human beings. Several laboratories have reported evidence associating type-C oncornavirus with human malignancies by the presence of viral coat proteins, reverse transcriptase, and provirus DNA sequences (DNA copies of the viral RNA genome) in these tissues (7-14). Isolations of type-C oncornaviruses from cultured human tissues have been reported (15-19), but are clearly uncommon (20). . .
Special Surgery, New York City.A possible viral etiology for the pathogenesis of human systemic lupus erythematosus (SLE) has received much attention (21-27), but no specific virus has Supported in part by grants from the USPHS (AM 14627), the Lupus Erythematosus Foundation, and the John Lindsley Fund. been identified. The dehonst;ation of Cype-C oncornavirus involvement in the pathogenesis Of glomerulonephritis in New Zealand mice (28,29) has led to speculation that this class of virus may be involved in human disease, although more recent studies in mice have contested this association (30,3 1). Indirect evidence in support of this hypothesis has been based on immuneSubmitted for publication May 17, 1978; accepted July 6, chemical studies reporting the presence Of type-C oncornavirus proteins in spleens (32), peripheral lym-