Cloning of non-IgA Fc binding forms of the group B streptococcal beta antigens

摘要

The subject invention concerns the genetic manipulation of the gene encoding a group B streptococcal (GBS) surface protein known as the beta antigen. The beta antigen is known to bind to the Fc region of IgA immunoglobulins in a non-immune manner. The portion of beta antigen gene which encodes the IgA binding function has been identified and removed using genetic engineering techniques. The novel polypeptide encoded by the altered beta antigen gene does not bind to IgA but does immunoreact with monospecific anti-beta antigen antisera raised against the wild-type beta antigen protein. This non-IgA binding form of the beta antigen may be used as a component in a human vaccine to protect against GBS infections.