[Studies on diversification and restriction of immune response against glycopeptide antigens]

Abstract

The M and N human blood group antigens are complex glycopeptide determinants at the amino terminus of the red blood cell membrane glycoprotein, glycophorin A. The heavy and light chain variable region cDNA sequences were determined for eight murine monoclonal antibodies recognizing the M or N blood group determinants. Among anti-N, but not anti-M, hybridomas, apparent restriction was found: all four anti-N VH regions of the heavy chains were derived from the same family, VH2(Q52) and all used the same J4 gene segment. To determine whether the Fab fragments displayed on the bacteriophage surface retain the immunological characteristics of intact antibodies, Fab-phages were constructed from five murine monoclonal antibodies recognizing glycophorin A. In each case, the Fab-phage had similar immunological characteristics as the respective antibodies. These results suggest that Fab-phages may be useful in studying the immune response to human glycosylation-dependent peptidic epitopes.