Cellular Formation of Vibriolytic Antibody by Mouse Immunocytes: Cytokinetics and Specificity

Abstract

Abstract A vibriolytic plaque assay in agar gel was developed which enumerates immunocytes secreting antibody to the common and type-specific antigens of Vibrio cholerae. No antibody-forming cells were found in the spleen of random bred or inbred mice prior to immunization with V. cholerae. Following immunization there was a consistent latent period of approximately 2 days before the first appearance of plaqueforming cells (PFC), followed by a rapid increase that reached a peak approximately 10 to 12 days after immunization. PFC directed against both the common and the type-specific antigen could be readily enumerated by testing individual spleen cell suspensions against both the homologous and heterologous vibrio strains, which are known to share a common antigen. A good correlation was evident between the appearance of PFC and circulating vibriolytic and agglutinating antibody, except for the long delay between the appearance of serum antibody and attainment of peak titer after 28 days. Anti-mouse globulin serum inhibited PFC, attesting to the immunoglobulin nature of the reaction, and inhibition tests with vibrio antigens, in the form of intact vibrios or lipopolysaccharide extracts, evinced the specificity of the PFC response.