Effects of natural suppressor cells on production of Th1 and Th2 cytokines and proliferation of polarized T cells.

Natural suppressor cells from the bone marrow of intact animals and mice with Th1- and Th2-dependent immune response largely suppressed the production of Th1 (IFN-gamma, IL-2) and Th2 cytokines (IL-4). Antiproliferative activity of natural suppressor cells from intact and immunized animals was mediated by NO. Proliferation of Th1 cells was suppressed greater than that of Th2 cells.

Mechanism of antitumor activity of bone marrow natural suppressor cells.

Co-culturing of P-815 tumor cell strain and intact mouse bone marrow cells nonadherent to plastic resulted in the appearance of soluble mediators with antitumor activity. Bone marrow cells start releasing these antiproliferative factors only after signal exchange with the target tumor cells. The cell-cell contact is an important factor for the induction of antitumor activity.

Effect of individual and combination treatment with cytokines on expression of sialoadhesin by bone marrow macrophages.

We studied the effects of lipopolysaccharide, interferon-gamma, interleukin-1, or tumor necrosis factor-alpha and combination treatment with tumor necrosis factor-alpha and interleukin-1 or interferon-gamma on the expression of sialoadhesin receptors on the membrane of bone marrow macrophages, macrophage adherent ability, and production of nitric oxide by these cells. Sialoadhesin expression was evaluated by binding of macrophages to sheep erythrocytes labeled with radioactive (51)Cr. Treatment of bone marrow cells with interferon-gamma improved adhesive properties of macrophages, but did not modulate expression of sialoadhesin.

Effect of antibodies to histamine in ultralow doses on production of allergen-specific antibodies.

We studied the effects of potentiated antibodies to histamine on production of IgE and IgG1 in response to 3-fold immunization of mice with ovalbumin in doses of 0.5, 10, and 100 microg. The course of treatment with antibodies to histamine suppressed production of allergen-specific IgE and IgG1 in mice 2-fold immunized with ovalbumin in doses of 100 and 0.

Hemopoietic and lymphoid organs in AKR/JY mice with thymic lymphoma.

Cytological and histological studies of the thymus, bone marrow, peripheral blood, spleen, and lymph nodes in 6-9-month-old AKR/JY mice showed that the risk of thymic lymphoma in these animals increased with age. Generalization of the tumor process was observed in mice aged over 8 months and first involved the spleen, then the lymph nodes, bone marrow, and liver. A case of primary lymphoma in the spleen was detected.