Expression of an idiotype (Id-460) during in vivo anti-dinitrophenyl antibody responses. II. Transient idiotypic dominance.

Abstract

After immunization of mice with 2,4-dinitrophenyl-ovalbumin (DNP-OVA), strains having Igh-Va genes and able to express L chains of the V.kappa.1 group produce high levels of anti-DNP antibody bearing an idiotype (Id-460) associated with the combining site of the BALB/c DNP-binding myeloma protein MOPC 460. Expression of Id-460 in serum is transient; Id-460 levels peak early in the response and are regulated independently of total anti-DNP antibody. In this paper, the transient dominance of Id-460 expression has been confirmed at the cellular level by inhibition of splenic anti-DNP plaque-forming cells (PFC) with rabbit anti-Id-460 antiserum. Id-460+ PFC can account for 52-91% of anti-DNP PFC early after secondary challenge with DNP-OVA. Id-460 is represented at these high levels in IgM, IgG1 and IgG2a, the 3 isotypes tested in the PFC assay, as well as in IgE, as tested by passive cutaneous anaphylaxis. Thus, there is no preferential association of Id-460 with a given isotype. Id-460 is evidently a dominant idiotype in the anti-DNP antibody response of BALB/c mice to DNP-OVA. This dominance is expressed transiently and is independent of isotype. A further conclusion from these studies is that regulation of isotype expression is independent of the regulation of idiotype expression in this system. Regulation of Id-460 expression may involve Ig-dependent helper T cells specific for Id-460 that induce Id-460+ B cells and also activate suppressor T cells, both events occurring via idiotype-anti-idiotype interactions.