Abstract
A panel of hybridoma antibodies obtained from lymphoid cells that were fused during a primary response (early) or a secondary response (late) gave results concordant with analysis of conventional, in vivo-produced anti-lysozyme idiotypes: early antibodies did not display the predominant anti-hen eggwhite lysozyme idiotype (IdX-HEL), whereas late antibodies all displayed IdX-HEL. Individual late hybridomas could each remove the entire anti-IdX-HEL activity by absorption, whereas early hybridomas could not. The epitope specificities of the hybridomas in both the early and late populations were heterogenous. Epitypic specificity in the response to HEL is apparently determined independently from idiotypic specificity and the predominant idiotype is selected for during the maturation of the anti-lysozyme response.