title: Immune response against the beta-galactosidase enzyme of E. coli at precursor cell level. I. Analysis of the secondary repertoire in BALB/c mice.
abstract: The BALB/c secondary response against the beta-galactosidase (beta-gal) enzyme of E. Coli was analyzed at the precursor cell level by using the splenic focus technique. Our results indicate that in immunized mice, one out of 18 000 B cells is able to recognize beta-gal. Among the families of anti-beta-gal monoclonal antibodies, a subset of specific antibodies was detected which is capable of protecting the enzyme from heat denaturation. The frequency of clones making protecting antibodies is 1 out of 90 000 and appears to be fairly constant among different individual mice. Further, the degree of heterogeneity of protecting antibodies analyzed in one individual is very high (250-fold difference in affinity) but comparable to other secondary repertoires. Specific frequencies are compared with previous findings relative to secondary responses against artificial haptens. It is suggested that a different type of recognition exists between protein determinants and artificial haptens. In addition, the relatively high proportion of clones making antibodies of the protecting type suggests that only a small proportion of antigenic sites on the beta-gal is actually able to stimulate an immune response.
mesh_terms: D000818:Animals; D000917:Antibody Formation; D000918:Antibody Specificity; D000937:Antigen-Antibody Reactions; D002999:Clone Cells / Q000276:immunology; D000939:Epitopes; D004926:Escherichia coli / Q000201:enzymology; D005696:Galactosidases / Q000276:immunology*; D006358:Hot Temperature; D007156:Immunologic Memory; D051379:Mice; D008807:Mice, Inbred BALB C / Q000276:immunology; D011489:Protein Denaturation; D013154:Spleen / Q000276:immunology; D001616:beta-Galactosidase / Q000276:immunology*
chemical_list: D000939:Epitopes; D005696:Galactosidases; D001616:beta-Galactosidase