Isolation of a C (Ibc) protein from group B Streptococcus which elicits mouse protective antibody
| Autor: | Matti V. Valtonen, Nancy J. Levy, Dennis L. Kasper |
|---|---|
| Rok vydání: | 1986 |
| Předmět: |
Antiserum
medicine.diagnostic_test Immunoprecipitation Heterologous Biology medicine.disease_cause Microbiology Molecular biology Antibodies Bacterial Epitope Streptococcus agalactiae Bacterial vaccine Molecular Weight Mice Infectious Diseases Western blot Antigen Bacterial Proteins Bacterial Vaccines medicine Animals |
| Zdroj: | Microbial pathogenesis. 1(2) |
| ISSN: | 0882-4010 |
| Popis: | The C (lbc) proteins of group B Streptococcus (GBS) have been shown to induce mouse protective antibodies when present as immunogens on whole organisms. However, characterization of specific proteins responsible for inducing protection has not been reported. We have grown type lc GBS in a dialysate of Todd Hewitt broth and analyzed the proteins extruded into the broth. Multiple proteins of varying size were visualized by SDS-PAGE. Ultrafiltration was used to separate the GBS components by molecular weight (MW) into 2 pools, those below 30000 MW but above 10000 MW (P10) and those above 30000 MW (P30). The P10 contained 4 major proteins, including a 14000 MW protein. Balb-c mice were immunized with the P10 fraction and the antisera used in mouse protection studies. This immune sera protected 100% of mice against challenge with type lb GBS and protection was not altered by prior absorption of the sera with type la or lb capsular polysaccharide. The P10 was fractionated by column chromatography and eluted proteins examined by SDS-PAGE and Western blot with the mouse protective antisera elicited to the P10. There was one major immunologically reactive protein at 14000 MW which eluted in a partially purified form from the column. The 14000 MW protein was reisolated from preparative SDS-PAGE gels and used to elicit antiserum in a rabbit. In mouse protection studies this rabbit antiserum protected mice against subsequent challenge with type lb GBS (89% protection). Surface antigens were extracted from 125 I-labelled type Ic GBS and immunoprecipitated with antiserum to the 14000 MW protein. The 14000 MW protein and multiple higher molecular weight proteins were immunologically cross-reactive suggesting the presence of shared epitopes. Thus the 14000 MW protein from type lc GBS that is antigenic and elicits mouse protective antibodies against the heterologous type lb GBS fulfills the criteria for a C protein of GBS. |
| Databáze: | OpenAIRE |
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