The serum albumin-binding region of streptococcal protein G (BB) potentiates the immunogenicity of the G130-230 RSV-A protein

BBG2Na is a protein comprising residues 130-230 of the respiratory syncytia l virus subgroup A (RSV-A) G protein (G2Na) fused to the albumin-binding do main of streptococcal G protein (BB). BBG2Na was cloned, expressed in Esche richia coli and renaturated. In rodent models, this subunit RSV vaccine adj uvanted in Alhydrogel(R) induced specific antibodies and conferred protecti on to RSV infection. Comparison of the antibody production in a BALB/c mous e model revealed that BBG2Na induced a stronger and earlier G2Na antibody r esponse than G2Na alone, without altering the Ige subclass distribution. To address the role of the BE part, we explored its carrier properties and sh owed that it is a Th dependent antigen, generating a more potent G2Na-speci fic B cell memory response and able to generate Th cells that provide help for G2Na antibody production. (C) 1999 Elsevier Science Ltd. ALI rights res erved.