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Isolation and characterization of fractions of Mycoplasma pneumoniae. II. Antigenicity and immunogenicity
Abstract:
Sobeslavsky, O. (National Institute of Allergy and Infectious Diseases, Bethesda, Md.), B. Prescott, W. D. James, and R. M. Chanock. Isolation and characterization of fractions of Mycoplasma pneumoniae. II. Antigenicity and immunogenicity. J. Bacteriol. 91:2126-2138. 1966.-Chemical and chromatographic fractions of disrupted Mycoplasma pneumoniae organisms were examined for serological and immunogenic activity. Complement-fixing activity was associated with lipid components, whereas precipitin activity was chiefly associated with polysaccharide components. When chemically extracted lipids were separated by thin-layer silica gel chromatography, only three of the nine fractions exhibited complement-fixing activity. Although lipids were highly active serologically, they were only weakly immunogenic. However, lipids combined with protein in lipoprotein complexes were highly immunogenic, stimulating high levels of complement-fixing, indirect-hemagglutinating, and growth-inhibiting antibodies. The specificity of these antibodies was directed chiefly against the serologically active lipid constituents of the organism. It was suggested that these serologically active lipids are present at the sites on the limiting membrane of M. pneumoniae at which antibody acts to inhibit growth of the organism. Only protein fractions adsorbed to tanned erythrocytes. The main function of protein in the indirect-hemagglutination reaction appeared to be that of serving as a carrier for the serologically active lipids.
Insights
Lipids from Mycoplasma pneumoniae showed strong serological activity, but low immunogenicity. Combining lipids with proteins created highly immunogenic lipoprotein complexes, crucial for antibody response against M. pneumoniae.
Area of Science:
- Microbiology
- Immunology
- Biochemistry
Background:
- Mycoplasma pneumoniae is a significant human pathogen.
- Understanding its antigenic components is key to developing effective diagnostics and therapeutics.
- Previous studies have begun characterizing M. pneumoniae antigens.
Purpose of the Study:
- To isolate and characterize fractions of Mycoplasma pneumoniae.
- To determine the antigenicity and immunogenicity of these fractions.
- To elucidate the role of lipids and proteins in the immune response to M. pneumoniae.
Main Methods:
- Disruption of Mycoplasma pneumoniae organisms.
- Chemical and chromatographic fractionation of cellular components.
- Assays for complement-fixing, precipitin, and indirect-hemagglutinating activities.
- Evaluation of immunogenic potential of fractions and complexes.
Main Results:
- Lipid components exhibited significant complement-fixing activity.
- Polysaccharide components were primarily associated with precipitin activity.
- Chemically extracted lipids showed weak immunogenicity despite high serological activity.
- Lipoprotein complexes, combining lipids and proteins, were highly immunogenic, inducing robust antibody responses.
- Antibody specificity was directed against serologically active lipid constituents.
Conclusions:
- Serologically active lipids are likely located on the M. pneumoniae membrane.
- These lipids are critical targets for growth-inhibiting antibodies.
- Proteins act as carriers for these immunogenic lipids in lipoprotein complexes.
- Lipoprotein complexes represent a key target for the host immune response to M. pneumoniae.