Association of circulating retroviral gp70-anti-gp70 immune complexes with murine systemic lupus erythematosus.

Abstract

Endogenous retroviral gp70 was investigated as a participant in the pathogenesis of a lupus-like disease that spontaneously develops in 4 kinds of mice (NZB, NZB .times. W, MRL/1 and male BXSB). Sera from these strains contains a heavy form of gp70 that varies in sedimentation rates from 9S-19S in sucrose density gradient analysis and appears with the onset of disease and persists throughout its course. Immunologically normal strains of mice do not develop rapidly sedimenting gp70 by 8-10 mo. of life. The fact that the heavy gp70 is selectively absorbed with anti-Ig[immunoglobulin]G antibodies or with Staphylococcus aureus protein A suggests that it is complexed with antibodies. The incidence and quantities of these gp70 IC [immune complex] rise with the progression of disease in all strains with lupus. Ig-complexed heavy gp70 may be involved in the pathogenesis of glomerulonephritis of mice with SLE.