EXPERIMENTAL IMMUNIZATION WITH A MONOCLONAL ANTI-IDIOTOPE ANTIBODY THAT MIMICS THE NEISSERIA-GONORRHOEAE LIPOOLIGOSACCHARIDE EPITOPE 2C7

An anti-idiotope monoclonal antibody (MAb), called CA1 (Ab2), was prod uced in mice against MAb 2C7, which recognizes a widely in vivo-expres sed gonococcal lipooligosaccharide (LOS) epitope, Mice immunized with MAb CA1 initially had a 2.5-fold increase in IgG (12-fold after a boos ter) but no increase in IgM anti-LOS (Ab1') antibody, Control mice imm unized with LOS had a 4.5-fold rise in IgG and 4-fold rise in IgM anti -LOS antibody, In rabbits, MAb CA1 elicited a 9-fold rise in IgG and a 3.3-fold rise in IgM anti-LOS (Ab1') antibody, Ab1' antibody bacteric idal activity was 1-2 logs greater than that produced by immunization with LOS, Ab1' mediated complete human polymorphonuclear leukocyte pha gocytosis of 2C7 epitope-positive (but not 2C7 epitope-negative) gonoc occi. MAb CA1 acts as a molecular surrogate (Ab2 beta) for the nominal LOS antigen and may form the basis for vaccine candidates for human i mmunization against Neisseria gonerrhoeae.