Xenotropic virus and autoimmunity in NZB mice.

The high-grade expression of xenotropic virus in NZB mice is determined by two autosomal dominant loci (Nzv-1 and Nzv-2). The progeny of crosses between NZB and the "nonautoimmune" virus-negative SWR strain segregate into three phenotypes: high-virus, low-virus, and virus-negative. The virologic phenotypes of the animals could be dissociated from the presence of either autoantibodies or immune complex-deposit nephritis and the latter could develop in the crosses without deposits of viral antigens in the glomeruli.