ABSTRACT
The variable regions of immunoglobulin genes have the potential to generate a large number of antibody specificities by a variety of recombinatorial, combinatorial, and somatic processes occurring during B-cell development. These variable regions must also encode for the idiotypic (Id) determinants of immunoglobulins that are proposed to be involved in the regulation of the immune system. The chapter discusses the experimental evidence favouring a functional role of perinatal multispecific B cells in the selective expansion of appropriate clones as they arise during development and their eventual constitution of the normal adult B-cell repertoire. There is a high probability that the corresponding B cells interact in vivo in appropriate microenvironments, and that these interactions may have significant influences on the developing B-cell repertoire. The processes leading to the uniform acquisition and establishment of the BALB/c adult B-cell repertoire involve complex idiotope-directed interactions that appear to proceed from the early-appearing B cells to the later-appearing ones in a cascade of Id-directed signals.
