The Role of Antibodies in Anti- Brucellosis Immunity
The article presents materials on the study of the bactericidal activity of various blood fractions (serum, plasma, various cell populations of polymorphonuclear and mononuclear lymphocytes) from immune and intact animals against brucella. For studies, blood from immune and intact animals was separated into composite fractions by gradient centrifugation. After immunization of adult heifers with a vaccine from Brucella abortus 19 strain. A suspension of brucella from the vaccine strain Brucella abortus 19 was injected to a final concentration of 1 billion m.c. in test tubes with different blood fractions from immune and intact animals. The brucella concentration in the bacterial mass was determined by the optical turbidity standard. Antibodies detected during the diagnosis of brucellosis and whose visible manifestation is the agglutinating and complementbinding effect, most likely play only the role of a witness of the contact of the body's immune system with the antigen. "Precipitating" antibodies, which exhibit an opsonizing effect and can block epitopes that act as a "pathogenicity factor" in essence, "protective antigens", can play a positive role in antibrucellosis immunity. Considering the prevailing role of the cellular immunity in brucellosis, assessing the effectiveness of some vaccines only for agglutinogenicity is not justified and does not reflect the true state of things. Agglutinating and complement binding antibodies that detected in the diagnosis of brucellosis are not significant in anti-brucellosis immunity and play a role, mainly a "witness" of the contact of the body's immune system with the pathogenic principle. Immunity in brucellosis is predominantly cellular, but some "precipitin" antibodies, exhibiting the phenomenon of opsonization and blocking the pathogenicity factor, play a positive role in antibrucellosis immunity. A reliable assessment of the immunogenicity of agglutinogenic and weakly agglutinogenic vaccines against brucellosis is possible only using the direct infection method. The conclusion is made about the cellular nature of the immunity in brucellosis, however, some "precipitin" antibodies play a positive role in anti-brucellosis immunity.