This study is concerned with the evaluation of the size of the repertoire of monoclonal antibodies to a (1-6) dextran. The contribution to antibody diversity and specificity in this system of individual complementarty defe mining regions (CDRs will be explored by site-directed mutagenesis replacing individualCDRs by glycines and then restoring the original CDR residues, one or two at a time. Fine structures of sites will be characterized by parameters such as size and shape, cavity vs. groove-type sites, association constants, relative contribution of each sugar in the epitope to binding including the use of fluorinated mono-and oligosaccharides. The repertoire of anti-idiotypic and anti- antiidiotypic antibodies inluding internal image antibodies will be defined. All these parameters will be correlated with derived amino acid sequences. Molecular modeling of other hybridomas established by immunochemical data to have cavity and groove-type sites will be continued. A human antibody repertoire of an individual who has been studies over forty-five years with respect to antibodies to various antigens, will be transferred to severe combined immuno deficient (SCID) mice to evaluate various responses to renewed immunization. An attempt will be made to synthesize the VH and VL expressed germ-line nucleotide chains of the human antibody to the group B meningococcal polysaccharide and attach them to human C 4 or C 1 and CL constant regions and evaluate the protective and other properties of this synthetic human antibody as a therapeutic agent since no effective group B vaccine is available. Further structural studies on the antibody and lectin specificities of large fragments of Smith and Carlson degrades blood group A,B,H substances, and on comparisons of the repertoire of anti-blood group A,B,and H substances in humans and mice will be carried out.
