[The beta-carotene stimulation of cellular immunity reactions in mice]. / Stimuliatsiia beta-karotinom reaktsii kletochnogo immuniteta u myshei.

The immunomodulating properties of synthetic beta-carotene were studied in C57Bl/6 and BALB/c mice using the tests of proliferative, cytotoxic and suppressor activity, and evaluating the adhesive capacity of macrophage lineage cells. Long-term feeding of C57Bl/6 mice with beta-carotene microgranules (0.1-0.5 mg of active substance per mouse) led to enhanced T cell proliferative response to ConA, which lasted for 15-45 days. Administration of beta-carotene oil solution to BALB/c mice previously immunized with alloantigens (0.17-0.34 mg of beta-carotene per mouse) enhanced T-cell cytotoxicity against L-929 and YAC-1 cells and macrophage cytotoxicity against L-929 cells. The treatment also reduced T-suppressor activity as shown in the assays of inhibition of the lymphocyte blast transformation reaction and mixed lymphocyte culture. The treatment with both preparations of beta-carotene enhanced the adhesive properties of macrophages and related cells, and induced the increased production of oxygen active radicals by these cells.

[The effect of the complex platinum (IV) compound oxoplatinum on the immune system]. / Nekotorye aspekty vliianiia kompleksnogo soedineniia platiny (IV)-oksoplatiny na immunnuiu sistemu.

The effect of a Pt (IV) complex compound--oxoplatinum on the humoral and cell immunity in mice was studied. It was established that the drug produced dose-dependent inhibition of T-dependent humoral response to ram erythrocytes. Oxoplatinum appeared to be a costimulator of a mitogen phytohemagglutinin in lymphocyte proliferation slightly influencing allogen-induced proliferation. The stimulation of T-lymphocyte cytotoxicity by small doses of oxoplatinum was also found.

[Scanning electron microscopic method for studying the interaction of normal peritoneal macrophages with tumor cells]. / Izuchenie metodom skaniruiushchei élektronnoi mikroskopii vzaimodeistviia normal'nykh peritoneal'nykh makrofagov s opukholevymi kletkami.

It is shown that the damage action of normal peritoneal macrophages of mice includes inhibition of the proliferating activity of the mastocytoma P-815 cells and their complete destruction accompanied by the breaks of their cytoplasmic membrane. Scanning electron microscopy was used to reveal two types of contacts between peritoneal macrophages and cells P-815; the loss of microvilli and the appearance of blebs on cell surface in the case of adsorption of P-815 cells on macrophages; the contact through long filopodia which are sent forth by macrophages in the case when contacting cells are at some distance from each other.

[Immunomodulating and antitumor activity of polysaccharides of plant origin]. / Immunomoduliruiushchaia i protivoopukholevaia aktivnost' polisakharidov rastitel'nogo proiskhozhdeniia.

The effect of the polysaccharides tagetan, palustran, and zymosan injections to BALB/c mice on the formation of cytotoxic T-lymphocytes in allogenic mixed culture has been studied. Lymphocytes from a 5-day-old mixed culture were characterized by the greatest cytotoxic activity, with spleenocytes serving as reacting cells in mice injected 12-50 mg/kg of tagetan, 20 mg/kg of zymosan and 10-100 mg/kg of palustran, 7, 3 and 5 days, respectively, before the beginning of allogeneic stimulation in vitro. To determine correlation between immunostimulating and antitumor activity 25 mg/kg of tagetan every 14 days, 20 mg/kg of zymosan every 6 days, and 10 mg/kg of palustran every 6 days, were injected to BALB/c and BALB/c nu/nu mice prior to and following subcutaneous implantation of Crocker sarcoma cells. By the end of the first month of immunotherapy the tumour size in mice on tagetan or zymosan was 2-2,5 times smaller than in control animals. Tumour growth inhibition with palustran was about 30%. Polysaccharide administration to BALB/c nu/nu mice was not accompanied by tumour growth inhibition. The data obtained suggest that inhibition of Crocker sarcoma growth in mice injected the above polysaccharides is mediated by stimulation of antitumour T-cell activity.

[Effect of synthetic beta-carotene on the formation of cytolytic T-lymphocytes]. / Vliianie sinteticheskogo beta-karotina na obrazovanie tsitoliticheskikh T-limfotsitov.

The effect of intraperitoneal injection of beta-carotene in different doses on the formation of cytolytic T lymphocytes (CTL) in a one-way mixed lymphocyte culture (MLC) of allogeneic mice was studied. The maximal cytotoxic activity of lymphocytes was attained in the MLC with splenocytes of mice which received 10 mg/kg beta-carotene 6 days before experimentation. The correlation was studied between the beta-carotene ability to stimulate CTL formation and antineoplastic activity. It was discovered that injection of beta-carotene in doses and times provoking maximal CTL induction had no effect on the animals' lifespan and the size of transplanted sarcoma 180.

[Ultrastructure of the conjugates of cytolytic T-lymphocytes and target cells]. / Ul'trastruktura kon'iugatov tsitoliticheskikh T-limfotsitov i kletok-mishenei.

Conjugates of target cells and of cytological T-lymphocytes obtained on the 11th day after alloimmunization were investigated. The conjugates formed small and medium lymphocytes; mature secretory granules, crystal-like structures and lipids were revealed in their cytoplasm. The lymphocyte is spherical, the area of contact with the target cell does not exceed 5 to 15%. Cytolysis of target cells is observed after 30 to 60 minutes of incubation. The lymphocyte becomes flattened, its nucleus acquires an oval form, and the area of contact with the target cell increases considerably. At the same time hypertrophy and change of orientation of Golgi's complex to the area of contact with the target cell, coalescence of the secretory granules with lipids and crystal-like structures, the appearance of immature secretory granules and vacuolar degeneration of mitochondria are demonstrated. The lymphocyte membrane becomes "desquamated"; structures connected with it, named "membranosomes" are described. It is suggested that the secretory processes in the cytoplasm of cytolytic T-lymphocytes are activated in their interaction with target cells.