title: Serum immune response to Shigella protein antigens in rhesus monkeys and humans infected with Shigella spp.
abstract: The serum antibody response to proteins encoded by the virulence-associated plasmid of Shigella flexneri was determined in monkeys challenged with virulent S. flexneri serotype 2a. With water-extractable antigen in an enzyme-linked immunosorbent assay, a significant increase in antibody titer against proteins from a plasmid-carrying, virulent strain of S. flexneri serotype 5 could be demonstrated in convalescent sera. There were minimal antibody titers against proteins from an avirulent (plasmid-free) organism. Previously identified plasmid-coded polypeptides a, b, c, and d were predominant antigens recognized by a majority of the convalescent sera in immunoblots. An additional 140-megadalton plasmid-coded polypeptide was also recognized by half of the sera. Convalescent serum from an infected monkey recognized antigens on the bacterial surface in several different plasmid-containing Shigella species and in an enteroinvasive Escherichia coli strain. A survey of sera obtained from children 5 to 10 years of age who had been infected with S. flexneri or S. sonnei revealed high enzyme-linked immunosorbent assay titers in both acute and convalescent sera against a water extract from a virulent Shigella strain. In contrast, children under 3 years of age had no antibody titer in either acute or convalescent sera against the virulence-associated shigella proteins, while 3- to 4-year-old children mounted an immune response against these proteins only in convalescence.
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis; D000942:Antigens, Bacterial / Q000235:genetics / Q000276:immunology*; D001425:Bacterial Outer Membrane Proteins / Q000276:immunology; D001426:Bacterial Proteins / Q000276:immunology*; D004405:Dysentery, Bacillary / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007074:Immunoglobulin G / Q000096:biosynthesis; D008253:Macaca mulatta / Q000276:immunology; D008970:Molecular Weight; D010957:Plasmids; D012760:Shigella / Q000276:immunology*
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D007074:Immunoglobulin G