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[Identification of the autoagglutination factor of Hms- cells of the plague agent]
Abstract:
A search for cellular components responsible for autoagglutination (AA) in broth and salt solutions of Hms- cells of the plague agent Yersinia pestis was performed. The AA- mutants were obtained using vaccine strain Y. pestis EV76 derivative containing one species-specific plasmid pYP. The mutants were shown to differ from the parent strain by the decreased surface hydrophobicity, insensitivity to plague diagnostic L-413c bacteriophage and negative haemagglutination reaction with antibodies to F1 capsular substance of the plague agent. The mutants did not differ from the parent strain by electrophoretic mobility and immunochemical activity of LPS but were characterized by the absence of a 17 kDa protein on the cell surface. The AA+ cells that lost this protein after weak alkali extraction were less hydrophobic and failed to express AA in 0.5 M ammonium sulfate. After the extraction, the cells lost the ability to neutralize L-413c and to react with the anti-F1 antibodies, while both activities as well as 17 kDa protein were detected in the extracts. Thus, the 17 kDa protein is suggested to be a hydrophobic surface antigen which acts as a receptor of the L-413c bacteriophage and represents an AA factor of Hms- cells of Y. pestis.
Insights
A 17 kDa surface protein in Yersinia pestis is crucial for autoagglutination and acts as a receptor for L-413c bacteriophage. Its absence reduces cell hydrophobicity and affects F1 antibody reactions.
Area of Science:
- Microbiology
- Immunology
- Bacteriology
Background:
- Yersinia pestis, the plague agent, exhibits autoagglutination (AA) in certain solutions.
- Understanding the cellular components involved in AA is essential for Y. pestis research.
Purpose of the Study:
- To identify the cellular components responsible for autoagglutination in Hms- Yersinia pestis cells.
- To characterize the role of these components in cell surface properties and interactions.
Main Methods:
- Generation of autoagglutination-negative (AA-) mutants from a Y. pestis vaccine strain.
- Analysis of cell surface hydrophobicity, bacteriophage sensitivity, and immune reactions.
- Extraction and characterization of surface proteins, including a 17 kDa protein.
Main Results:
- AA- mutants showed decreased hydrophobicity, insensitivity to L-413c bacteriophage, and lacked reaction with anti-F1 antibodies.
- A 17 kDa surface protein was absent in AA- mutants and its removal from AA+ cells reduced hydrophobicity and AA.
- The 17 kDa protein was found in extracts and demonstrated L-413c neutralization and anti-F1 antibody reactivity.
Conclusions:
- The 17 kDa protein is a hydrophobic surface antigen essential for Y. pestis autoagglutination.
- This protein functions as a receptor for the L-413c bacteriophage.
- The 17 kDa protein is involved in the F1 capsular substance-mediated immune response.
