Some cytological aspects of rat mammary cancer therapy with soluble tumor-associated antigens (sTAA- p66 and p51) and the anticancer drug cyclophosphamide (CPA) are analyzed. Vaccination with sTAA results in a significant increase in the areas related to the production of T and B cells in the white pulp (germinal center and PALS) and in the marginal zone of the spleen. sTAA stimulate the production of CD8+ lymphocytes inside the tumors and in bone marrow, and of CD8+ thymocytes in the medulla of the thymus. Treatment of rats with CPA decreases the activity of lymph cells in tumors, especially of CD4+ lymphocytes. In the spleen, CPA decreases the size of areas related to the production of B and T cells. In the bone marrow, CPA affects the process of myelogenesis and causes significant substitution of cellular components with fatty tissue. The combined treatment with CPA and sTAA increases the number of lymph cells and the apoptotic index in tumors, and restored the rate of B cells producing in the spleen. Similar effect was observed in lymph nodes with accumulation of B lymphocytes in the primary and secondary follicles, and of T lymphocytes in the paracortical zone. In the thymus, CPA alone or in combination with sTAA repairs the inhibitor effect of a carcinogen on synthesis of CD4+ and CD8+ thymocytes. In combined using with CPA, sTAA activate the B- and T-lymphocyte production in the host’s immune system and decrease the toxic side-effects of a drug.

Keywords: Antigens, Neoplasm - administration & dosage, Cancer Vaccines - administration & dosage, Lymphoid Tissue - immunology, Lymphoid Tissue - pathology, Mammary Neoplasms, Experimental - immunology, Phosphoproteins - administration & dosage, Trans-Activators - administration & dosage, Antigens, Neoplasm - administration & dosage, Antineoplastic Agents, Alkylating - therapeutic use, Cancer Vaccines - therapeutic use, Combined Modality Therapy, Cyclophosphamide - therapeutic use, Lymphoid Tissue - pathology, Mammary Neoplasms, Experimental - therapy, Phosphoproteins - immunology, Solubility, Trans-Activators - immunology, Transcription Factors, Tumor Suppressor Proteins