Genetic studies on the skin lupus band test in New Zealand mice.

We found that the lupus band test (LBT) is frequently positive in the tail skin in NZB and NZB X NZW (B/W) F1 hybrid mice. Genetic mode of development of this positivity was investigated in female NZB, NZW, B/W F1 hybrid and B/W F1 X NZW back-cross mice and the incidences were 60%, 0%, 100% and 42% by 12 months of age, respectively. It was found that B/W F1 hybrid mice showed not only a higher incidence but also an earlier onset of LBT positivity than did the parental NZB mice. These findings suggested that a single dominant locus in NZB strain determines the appearance of a positive LBT and that this trait is to a great degree intensified by the involvement of NZW gene(s) in B/W F1 hybrid mice. Linkage studies indicated that the NZB gene is to some extent linked to H-2 complex. In addition, there were significant associations between the LBT positivity and the appearances of anti-dsDNA antibodies and renal disease in B/W F1 X NZW back-cross mice. Thus, it is suggested that the NZB-LBT gene is the gene itself or closely linked, on chromosome 17, to that related in part to the occurrence of anti-DNA antibodies and renal disease. There was a lack of retroviral gp70 deposition at the dermo-epidermal junction in NZB and B/W F1 hybrid mice, in that the gp70 is the predominant antigen in the immune complexes deposited in the diseased renal glomeruli.