ANTIBODY REACTIVITY PROFILES FOLLOWING IMMUNIZATION WITH DIVERSE PEPTIDES OF THE PERB11 (MIC) FAMILY

PERB11 (MIG) is a gene family possessing multiple copies located withi n the MHC. Structurally, PERB11 is related to the MHC class I, neonata l IgG Fc receptor (FcRn) and Zn-alpha(2)-glycoprotein molecules. The M HC class I family is complex in terms of its genomic arrangement, expr ession and function, and available evidence suggests that the PERB11 f amily may be similarly complex. We have adopted an approach to study t he expression of such complex gene families by immunizing with multipl e peptides and by screening the resulting antibodies against a large r ange of tissues. The amino acid sequences of PERB11.1 and PERB11.2 as well as those of other related molecules were analysed and compared. P eptides were chosen for immunization based upon (i) loop formation wit hin the equivalent known structure of the MHC class I molecules (ii) i mmunogenicity by computer analysis; and (iii) evolutionary relationshi ps. Antibodies in serum from immunized rabbits bound to three out of s ix peptides used for immunization. ELISA and immunoprecipitation demon strated binding both to the peptides and to the PERB11.2 recombinant p rotein. By immunofluorescent staining of various tissues of several sp ecies, the three antisera generated overlapping profiles of activity. These included reactions with kidney, small and large intestine, oesop hagus, testis, ovary and human neutrophils. This is the first descript ion of antibodies induced by the PERB11 peptides. The extreme complexi ty of these profiles requires further investigation, but may be explai ned in terms of antibodies against diverse products of the PERB11 gene family and/or related molecules.