Measurement of antigen-specific IgG autoantibody production in vitro.

This report describes the development of a direct, highly sensitive and reproducible microassay for measuring picogram amounts of IgG antibody produced in spleen cultures of NZB/NZW female mice and specific for a well defined nucleic acid antigen (native ssRNA). The spontaneously synthesized antibodies were extensively purified from the culture supernatants. The isolated IgG anti-RNA antibodies had a high affinity, limited heterogeneity, and were specific for RNA as compared with DNA. Spleen cell cultures produced quantities of anti-RNA antibodies sufficient to account for a large proportion of the circulating anti-RNA antibodies in the whole animal. However, our results provide no evidence for the recently published suggestion (Sawada) et al., 1977. J. Immunol. 119:355) that autoreactive lymphocytes are released from normal immunoregulatory control during in vitro culture conditions.