Immunological Analysis of Glycolipids and Lipopolysaccharides Derived from Various Mycoplasmas

Abstract

The lipids and lipopolysaccharides of five mycoplasmas were examined for complement-fixing activity to antimembrane rabbit sera. Total glycolipid fractions and the aqueous phenol fractions (lipopolysaccharides) from the membranes of Acholeplasma laidlawii, A. modicum, A. axanthum, and Mycoplasma neurolyticum exhibited significant antigenic activity. The glycolipids and phosphoglycolipids from Thermoplasma acidophilum were either anticomplementary or did not react due to their extreme hydrophobic nature. High activity was found using the lipopolysaccharide of T. acidophilum. The pure glycolipids and phosphoglycolipids of the Acholeplasma and Mycoplasma species also exhibited significant complement-fixing activity. Acylation of the sugar residues of these lipids reduced or negated complement-fixing activity. Double cross-reactions between the glycolipids of A. laidlawii and A. modicum appeared to be due to mono-and diglucosyl diglycerides of identical structure. Specificity of glycolipid structure was noted by the absence of cross-reactions between A. laidlawii and M. neurolyticum, the glycolipids of which differ only in the nature of the glucose linkages. The existence of lipopolysaccharides in the membranes of mycoplasmas and their complement-fixing activity in the presence of antimembrane sera suggest their possible importance as specific antigenic determinants.

Ultrastructural Visualization of Surface Carbohydrate Structures on Mycoplasma Membranes by Concanavalin A

“…A small amount of a polysaccharide was isolated (17) and purified (13,18) from M. mycoides var. capri.…”

Characterization of the metabolism inhibition antigen of Mycoplasma arthritidis

“…For Mycoplasma pneumoniae the specific complement-fixing and growth-inhibiting antibodies are directed against glycolipid antigens, which, although highly antigenic, are only weakly immunogenic in a purified state and function primarily as haptens (31,43). The lipids of a number of other mycoplasmas also are antigenic (39,44).…”

Identification of the major antigenic determinants on lipoglycans from Acholeplasma granularum and Acholeplasma axanthum

“…Structural features of oligosaccharide chains are known to dictate the antigenic specificity of many biological molecules, including streptococcal, klebsiella, and pneumococcal polysaccharides (5,8,9,15), gram-negative bacterial lipopolysaccharides (3), blood groups (4), and glycolipids (14). Lipoglycans, which have been isolated from the cytoplasmic membranes of species of Acholeplasma, have been shown to elicit the production of specific antibodies in rabbits when introduced via the footpad together with Freund complete adjuvant, by the intravenous route when adsorbed onto autologous erythrocytes, or by either route as integral parts of the acholeplasmal membrane (7).…”