Schalch , Wright

Standard immune responses are the sum of many clonal responses, cross-reactive and specific. Any study of clonal expression as well as analysis of its products requires the separation of clones. There are several approaches to this goal (1-3). The one we used was to generate immune responses of restricted heterogeneity where a limited number ofclonotypes determine the response (4, 5). The prerequisites for the induction of such responses are homogeneity of the immunogen and the genetic background of the animals immunized (I, 4-9). Bacterial cell walls carrying regularly spaced polysaccharide moieties on their surface meet the demand for homogeneity of the antigen (1). Certain breeds of rabbits and inbred mouse strains fulfill the genetic requirements (4-9). Considering both of these conditions antibody responses of predictable clonal patterns can be elicited (10). Although most of the early work emphasized the restricted heterogeneity of antipolysaccharide antibody responses (1, 4-9) we report here in detail that clonal IgG antibody patterns in response to polysaccharide determinants are rather complex. Despite this complexity it is possible to isolate, by a combination of methods, antistreptococcal group A-variant antibodies in single-band purity (11). In using these antibodies, distinct functions of monoclonal IgG antibody could be ascribed to fine specificities for different determinants on a linear polysaccharide chain.