SEQUENCE HETEROGENEITY OF MURINE ACQUIRED-IMMUNODEFICIENCY-SYNDROME VIRUS - THE ROLE OF ENDOGENOUS VIRUS

A defective murine leukemia virus is the causative agent of murine acq uired immunodeficiency syndrome (MAIDS). We have cloned cDNAs from bot h virus infected and non-infected cells using the PCR methods with pri mers corresponding to the franking sequence of the unique p12 gag gene . Sequence analysis of these cDNA clones revealed: (i) the presence of endogenous virus related to MAIDS virus in C57BL/6 mice, (ii) B cell lineage specific expression of endogenous virus and (iii) extensive he terogeneity of MAIDS virus recovered from virus infected cells due to the recombination of the related viruses (defective pathogenic virus, ecotropic virus and endogenous virus). These findings suggest that the creation of virus variants in infected cells may play an important ro le in virus pathogenesis and escape from immune attack during the deve lopment of MAIDS.