MAPPING OF ANTIGENIC AND IMMUNOGENIC SITES OF HAEMOPHILUS-INFLUENZAE OUTER-MEMBRANE PROTEIN P6 USING SYNTHETIC LIPOPEPTIDES

The immune response to the P6 protein of Haemophilus influenzae was ch aracterized with 24 synthetic icosapeptides and 45 dodecapeptides conj ugated to the immune stimulator mitoyloxy)-(2RS)-propyl]-(R)-cysteinyl -(S)-serine. The antigenicity of these lipopeptides was investigated b y enzyme-linked immunosorbent assays with rabbit anti-P6 serum. The ep itopes of P6 protein were identified and localized within residues 31- 46 and 59-70 and in the C-terminal part of the P6 protein. Mice were i mmunized with lipoicosapeptides without using additional adjuvants or carriers and the antibody titers were measured with isolated P6 protei n and lipopeptides in a dot blot assay. Lipopeptides containing the se quence pattern QILDAHAA (P6 47-54) and the mouse B cell epitope GEYV ( P6 43-46) induced high titers of anti P6 antibodies. These murine anti bodies were able to neutralize the intact bacterium Haemophilus influe nzae.