Genetic and temporal control of neonatal antibody expression.

Abstract

Two hybridoma cell lines were established with B cells derived from neonatal BALB/c spleen cells. The anti-dinitrophenyl (DNP) antibodies derived from these lines were characterized with respect to their isotype, affinity and isoelectric point. Antiidiotypic reagents were prepared that permit an analysis of the representation of antibodies sharing idiotype with these 2 hybridomas in the developing and mature B cell pool of BALB/c mice (Ihga) and other murine strains. One of the 2 antibodies, TF2-36, was indistinguishable from 14% of anti-DNP monoclonal antibodies derived in fragment culture from spleen cells of 1-4-d[day]-old BALB/c donors. B cells expressing this idiotype represented .apprx. 2% of the anti-DNP-specific repertoire after the 1st wk of neonatal development and into adulthood. The 2nd hybridoma antibody, TF2-76, was expressed at very low levels during the first several days of neonatal development: B cells expressing this idiotype increased in frequency during the 2nd wk of neonatal development representing 7% of all DNP-responsive B cells 12-13 d after birth. The proportion of B cells expressing this idiotype also decreased to .apprx. 2% in adults. The relatively late appearance of B cells bearing this idiotype was confirmed by their susceptibility to tolerance induction after the 1st wk of neonatal development. Both the early neonatal clonotype, TF2-36, and the late neonatal antibody clonotype, TF2-76, were expressed in a similar fashion in F1 mice constructed between Igha and Ighb parentals, but both were expressed at very low levels during the development of Ighb mice. The control of the magnitude of expression of these neonatal clonotypes appears to be associated with the Igh locus.