Induction of an immune response to the porin of Haemophilus influenzae type b by monoclonal anti-idiotypic antibodies.

Monoclonal anti-idiotypes were generated against monoclonal antibody (mAb) Hb-2 which recognized a highly conserved epitope on the outer membrane porin protein from Haemophilus influenzae type b (Hib). Four hybridomas reacting with F(ab') 2 fragments of Hb-2 were selected and characterized. Inhibition studies using syngeneic anti-anti-idiotypic antisera suggested that at least three different antigenic determinants on Hb-2 were recognized by these monoclonal anti-idiotypes. The binding of each anti-idiotype to Hb-2 was inhibited by Hb-2 whereas the reaction was not affected by any other anti-Hib mAb. Complete inhibition of the binding of anti-idiotype to the idiotype could be achieved with 10 micrograms of total outer membrane protein (OMP) from Hib suggesting that the anti-idiotypes might be directed against paratope-associated idiotypes. Outer membrane antigens not recognized by mAb Hb-2 did not inhibit the reaction. Furthermore, the pre-incubation of Hb-2 with each anti-idiotype specifically prevented the reaction of Hb-2 with its antigen. Antibodies with specificity for the porin were generated in guinea pigs immunized with anti-idiotypes AHb-22 and AHb-23. This study indicates that these particular monoclonal anti-idiotypes may be used as an antigen substitute for the porin of Hib in a xenogeneic species.