Anti‐mhc Immunity Detected Prior to Intentional Alloimmunization

Abstract

SUMMARY Naturally occurring H‐2‐specific antibodies can be detected rather frequently in sera of non‐alloimmunized mice by sufficiently sensitive techniques (Cerny‐Provaznik et al., 1985a; Cerny‐Provaznik & Ivanyi, 1985). In this report, we summarize our experiences with the preparation of monoclonal anti‐H‐2 antibodies obtained from hybridization experiments from non‐alloimmunized mice. From a total of 30 spleen cell hybridization experiments, we could isolate only four anti‐H‐2 monoclonal antibodies (mAb). Two of the m Ab are described in this report. Monoclonal antibody By‐2 is anti‐Kf and mAb By‐3 is anti‐Db, D5. We investigated which conditions favour the isolation of monoclonal H‐2‐specific antibodies from non‐alloimmunized mice. The presence of naturally occurring serum antibodies, the age of the spleen donor mouse or non‐specific B cell stimulation were not critical for the isolation of natural anti‐H‐2 mAb. We hypothesise that the ‘natural’ H‐2‐specific antibodies represent compartments of the B cell repertoire which were triggered by modified or aberrant self‐MHC expression.