Assessment of a Bacterial Adherence Colony (BAC) Method for Enumeration of Antibody-Forming Cells to E. Coli Somatic Antigen

[摘要] The number of individual lymphoid cells producing antibody to E. coli somatic lipopolysaccharides was studied in mice by means of a bacterial adherence colony technique. Cultures of spleen cells with bacteria in nutrient agar plates resulted in formation of adherent micro-colonies which could be differentiated microscopically from the much smaller colonies originating from non-adhering bacteria. The specificity of the antibody-producing cells was attested by their sensitivity to blocking with specific antigen and with anti-globulin serum.The adherence technique, performed in parallel with the direct complement-dependent bacteriolytic procedure, using a “lawn” of viable E. coli , detected more “background” antibody-forming cells in spleens of non-immunized mice. This difference was of the order of 10-fold.In immunized mice bacterial colony-forming cells were first discernible about 24 hr after immunization and reached a peak of 100,000 or more in the spleen by the 5th day after antigen atimulation. Maximal responses were elicited by 10 to 50 µg of antigen. The bacteriolytic plaque assay was less sensitive throughout.

[学科分类] 生物科学（综合）