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The method for the determination of bacterial antibodies to group B meningococci was worked out. The method was used for the determination of antibodies to group B meningococcal vaccine produced in the USSR. The dynamic study of antibodies to protein, polysaccharide and lipopolysaccharide antigens of group B meningococci was made by the method of the enzyme immunoassay (EIA), and the safety of the vaccine was studied by the determination of autoantibodies active against brain tissue antigens. The data thus obtained were indicative of the immunological activity of group B protein-polysaccharide vaccines, manifested by the capacity for stimulating bactericidal antibodies whose level increased 8- to 10-fold after the immunization of monkeys in 2 and 3 injections. Similarity in the dynamics of the formation of bacteriolysins and antibodies to protein antigen, as determined in EIA, was noted. The vaccine was found to stimulate no cytotoxic anticerebral antibodies in the glia migration test, which was indicative of the safety of group B meningococcal vaccine.

The protein-polysaccharide complex, isolated from group B N. meningitidis, is a variant of vaccine for the prophylaxis of group B N. meningitidis infection. In this investigation the influence of the complex of the physical properties of aluminium hydroxide gels, the amount of gel, pH and the duration of sorption on the process of sorption has been studied. Aluminium hydroxide has been shown to produce a stimulating effect on the response of mice to the polysaccharide and protein contained in the complex after immunization made in two injections. Gels with a smaller particle size have been found to possess greater adjuvant activity, as well as greater absorbing activity. The immunological activity of the complex, adsorbed ex tempore, has proved to be no different from that of the complex adsorbed in an hour.

The comparative study of two group B meningococcal vaccines manufactured in the USSR and in Cuba was made. The vaccine manufactured in the USSR contained the noncovalent compound of group B Neisseria meningitidis polysaccharide and outer membrane protein, and the Cuban vaccine contained group B N. meningitidis outer membrane proteins and group C N. meningitidis polysaccharide. The data obtained in this study indicated that both vaccines possessed immunological potency evaluated according to their capacity to stimulate the formation of bactericidal antibodies, whose level was found to increase eightfold after the immunization of monkeys in two injections. Besides, group B meningococcal vaccines did not induce the suppression of nonspecific protective activity characteristics of the body and did not stimulate the formation of autoantibodies to brain and liver tissues, which was indicative of the safety of these vaccines.

The hybridization of myeloma cells NP with lymphocytes of mice, immunized with protein isolated from Neisseria meningitidis strain Bc5 in a single injection into the spleen 3 days prior to fusion, made it possible to obtain 25-72% of hybridomas secreting antibodies to meningococcal antigens. The treatment of immune lymphocytes from these mice with the total preparations of nucleic acids, isolated by the phenol-detergent method from mouse myeloma cells NP and NS/0, induced an increase in the proliferative activity of lymphocytes; in some microcultures multilayer cell growth was observed on the bottom of the wells, whereas in the control microcultures such growth was absent. No synthesis of specific antibodies was detected in the cultures of lymphocytes whose proliferation was stimulated with nucleic acids.

The tumorigenic capacity of mouse B-cell hybridomas in both cloned and primary cultures was studied. The cells were selected for inoculation from 24-well plates and introduced into the spleen of syngeneic mice. The cells took in 50% of the animals. The cells of hybridoma tumors induced as the result of intrasplenic inoculation, when subcultured in the second passage following the standard scheme, i.e. inoculated intraperitoneally in a dose of 1 X 10(7) cells into mice previously treated with vaseline oil or pristane, produced tumors in 100% of the animals.