INFLUENCE OF GENES FROM THE MAJOR HISTOCOMPATIBILITY COMPLEX ON THE ANTIBODY REPERTOIRE AGAINST CULTURE FILTRATE ANTIGENS IN MICE INFECTED WITH LIVE MYCOBACTERIUM-BOVIS BCG

C57BL/10 and C57BL/6 mice (H-2b); BIO congenic mice with f, k, p, q, r , and s H-2 haplotypes; B10 mice with recombinant g2, o2, a, h2, h4, i 5, and bq1 H-2 haplotypes; and B6 mice with major histocompatibility c omplex (MHC) mutant bm1 and bm13 (class I) and bm12 (class II) haploty pes were infected intravenously with 4 x 10(6) CFU of live Mycobacteri um bovis BCG and examined by Western immunoblot analysis for serum ant ibodies against BCG culture filtrate antigens, following a boost injec tion with live BCG or with BCG culture filtrate. Parental B10 and B6 m ice reacted very intensely with three culture filtrate protein bands w ith estimated molecular masses of 37, 38, and 40 kDa. Response against the 40-kDa protein was stronger following a boost injection with live BCG than following a boost with culture filtrate. Sera from mice with f, p, i5, bm1, and bm13 haplotypes reacted strongly, with both the 37 -38- and 40-kDa antigens, and sera from mice with q and bq1 haplotypes showed a somewhat weaker reaction. Sera from mice with r, s, and bm12 haplotypes reacted against the 37-38-kDa antigen but not against the 40-kDa antigen, and sera from mice with the h2 haplotype reacted only with the 40-kDa antigen but not with the 37-38-kDa antigen. Sera from mice with the k, g2, o2, a, and h4 haplotypes showed, at most, a very weak reaction with the 37-38- and 40-kDa antigens. These results demon strate that MHC genes profoundly affect the antibody repertoire used a gainst culture filtrate antigens in mice infected with live M. bovis B CG. In particular, as shown in mice with the recombinant H-2 haplotype and in class II mutant bm12 mice, the I-A heterodimer controls the re cognition of the immunodominant 40-kDa antigen. By using crossed immun oelectrophoresis, this 40-kDa antigen was identified as antigen 88 acc ording to the reference system of Closs et al. for BCG antigens.