Presence of murine retroviral sequences in human cell line transplanted in immunosuppressed SCID-mice.

The SCID-hu mouse, a severe combined immunodeficient mouse transplanted with human hematopoietic cells, has been proposed as an experimental model for HIV-1 infection. However, like other animal models for infectious diseases, the SCID-hu mouse should provide the replication of the experimental agent without conferring any alteration during growth in the host. In this study using Southern blot hybridization, in situ hybridization and PCR analysis we demonstrate the presence of specific murine retroviral sequences in human cells recovered from the in vivo passages in SCID mice. Since the acquisition of endogenous retrovirus by human cells was demonstrated after their growth in nude mice, the data reported here extend this observation to the SCID model.