Isolation and Characterization of Fractions ofMycoplasma pneumoniaeII. 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 ofMycoplasma pneumoniae. II. Antigenicity and immunogenicity. J. Bacteriol.91:2126–2138. 1966.—Chemical and chromatographic fractions of disruptedMycoplasma pneumoniaeorganisms 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 ofM. pneumoniaeat 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.