[Immune response in experimental animals immunized with Burkholderia pseudomallei surface antigens]

The influence of the chromatographic fractions of B. pseudomallei surface antigenic complex (C, C1, D, H) on immune response in white rats and white mice was under study. These antigenic complexes were noted to produce perceptible stimulating effect on the immune system of white rats, in contrast to that of white mice. The immunization of the mice the above-mentioned fractions suppressed the phagocytic activity of peritoneal macrophages (PM) and slightly enhanced cell-mediated immunity. In experiments on white rats, fraction C induced the growth of specific antibody titers and stimulated the phagocytic activity of PM, as well as the indices of delayed hypersensitivity (DH). Fraction D showed a lower level of the induction of the phagocytic activity of PM and was inactive in the manifestation of cell-mediated immunity, but induced a high level of humoral immunity. Antigenic complexes C1 and H increased the phagocytic activity of PM and DH characteristics with a low level of antibody production. The studied fractions of the causative agent of melioidosis decreased the content of bactericidal cationic proteins (BCP) in rat blood neutrophils, and in mice a decreased content of BCP in phagocytes was registered. The fractions increased the activity of myeloperoxidase in blood neutrophils in mice and rats. As revealed with the use of immunoelectrophoresis, SDS PAAG electrophoresis and immunoblotting, the surface antigenic complex contained proteins of 18, 22, 39 kD and glycoproteins 42, 55, 90 kD. The latter glycoprotein was found in all the fractions under study, having protective properties.