Immunological Properties of the Cell Envelope Components of Vibrio cholerae

Abstract

Several immunobiological properties of cell envelope components of Vibrio cholerae such as mitogenicity, antigenicity, adjuvanticity and toxicity were tested in mice. Killed whole bacteria, spheroplasts, lipopolysaccharide and outer membrane proteins possessed mitogenic activity as determined by [3H]thymidine uptake in spleen cell cultures. All these components predominantly stimulated murine bone-marrow derived (B) lymphocytes. The mitogenicity induced by V. cholerae lipopolysaccharide was similar in magnitude to that observed with Salmonella typhimurium lipopolysaccharide. Vibrio cholerae lipopolysaccharide was mitogenic for gut-associated lymphocytes such as those obtained from Peyer's patches and small intestine. Antibody formation at the cellular level was detected by the haemolytic plaque assay. Plaque-forming cells to V. cholerae lipopolysaccharide were only detected when mice were immunized intraperitoneally with intact cells or with spheroplasts. Among the various cell envelope components, lipopolysaccharide alone possessed adjuvant properties as it increased the number of plaque-forming cells to sheep erythrocytes fourfold in mouse spleens. Also, lipopolysaccharide was the only component found to be toxic for the mouse (LD50 0 . 5 mg). Neither spheroplasts nor outer membrane of V. cholerae showed adjuvanticity or toxicity in mice.

Immunogenicity and protective role of an IgA reactive 31-kDa antigen of Vibrio cholerae O139

“…In the present study, proliferation of the mouse splenic lymphocytes was found to depend upon the concentration of stimulating antigen. These results are consistent with those of Lewis et al [37], who investigated the proliferative response of peripheral blood mononuclear cells (PBMCs) obtained from CT-B immunised subjects to CT-B, and Kabir and Mann [38], who studied the proliferation of murine splenic lymphocytes on stimulation with LPS or OMP of V. cholerae. The low SI and cpm values of proliferative responses recorded in the present study probably re¯ect the fact that oral administration of V. cholerae O139 strain MO45 induced only relatively small numbers of antigenspeci®c T-or B-cell precursors in the circulation.…”

The Serological Properties of the Cell Surface Proteins of Vibrio cholerae

“…Finally, extracted proteins had polypeptides similar to those of the outer membrane of V . cholerae isolated from the cell envelope by Triton X-100 (Kabir, 1980). Although the present method produced a few more polypeptides a major component in both the preparations had a molecular weight of 48000.…”

Identification and characterization of Vibrio cholerae surface proteins by radioiodination

“…Furthermore, the electrophoretic profile of V. cholerae outer membrane proteins in polyacrylamide gels is distinct from those of other gram-negative organisms. These studies and others (16,17,34) indicate that the outer membrane of V. cholerae is a complex structure containing many proteins.Proteins exposed on the bacterial surface are likely to contribute to colonization of the host, and improved knowledge of the surface proteins should further our understanding of their role in colonization. The surface proteins of several bacterial species have been identified by iodination with membrane-impermeable enzymes (15,20,29,31) or the water-insoluble reagent, 1,3,4,6-tetrachloro-3,6-diphenylglycouril (Iodogen) (33).…”