ABSTRACT
The dynamics of expression of the RT1A antigen of the class I major histocompatibility complex (MHC) in a Walker 256 tumor after its transplantation into Brattleboro rats with a genetic defect of Arginine-Vasopressin synthesis in the hypothalamus was studied. Expression of the RT1A antigen was detected by means of Western-blotting and flow cytometry in the tumor cells on the 14th-17th days after transplantation. In addition, a simultaneous increase in the portion of cells that express the RT1A antigen and in the level of its expression per cell was observed. It is presupposed that at a deficiency of Arginine-Vasopressin, a renewal of expression of the class I MHC antigens, which results in an increase of immunogenicity of this tumor and regression, occurs in the Walker 256 tumor in the Brattleboro rats.
Subject(s)
Carcinoma 256, Walker , Histocompatibility Antigens Class I/metabolism , Histocompatibility Antigens , Animals , Arginine/biosynthesis , Arginine/genetics , Arginine/immunology , Carcinoma 256, Walker/genetics , Carcinoma 256, Walker/immunology , Carcinoma 256, Walker/metabolism , Flow Cytometry , Histocompatibility Antigens/genetics , Histocompatibility Antigens/immunology , Histocompatibility Antigens/metabolism , Histocompatibility Antigens Class I/immunology , Rats , Rats, Brattleboro , Vasopressins/biosynthesis , Vasopressins/immunology , Vasopressins/metabolismSubject(s)
Immune System/embryology , Serotonin/deficiency , Animals , Antibody-Producing Cells/drug effects , Antibody-Producing Cells/physiology , Cell Proliferation/drug effects , Female , Fenclonine/pharmacology , Pregnancy , Prenatal Exposure Delayed Effects , Rats , T-Lymphocytes/drug effects , T-Lymphocytes/immunologyABSTRACT
Changes in the structure of the rat spleen and the distribution of immune proteasomes in it during early postnatal development have been studied using double immunofluorescent staining of tissue sections with antibodies to the LMP7 immune proteasome subunit and to specific markers of T and B lymphocytes. It has been shown that the white pulp on postnatal day 5 is not yet colonized by lymphocytes and contains a smaller amount of immune proteasomes than the red pulp. At this stage, T and B lymphocytes concentrate mainly in the red pulp. On day 8, B lymphocytes occupy the marginal zone, while T lymphocytes aggregate into dense strands close to the white pulp. By day 18, T lymphocytes form periarteriolar sheaths in the white pulp, and the contents of immune proteasomes in the red and white pulp become equally high. An increase in the total content of immune proteasomes in the spleen on the third postnatal week was revealed in our previous study by Western blotting. In addition to T and B lymphocytes, immune proteasomes have also been revealed in other spleen cell types, probably in macrophages and reticular cells of the white pulp. Thus, the postnatal development of the spleen is associated with an increase in the contents of immune proteasomes in it.
Subject(s)
Multienzyme Complexes/immunology , Proteasome Endopeptidase Complex/immunology , Spleen/growth & development , Spleen/immunology , Animals , Antigens, Differentiation/biosynthesis , Antigens, Differentiation/immunology , B-Lymphocytes/immunology , B-Lymphocytes/metabolism , Multienzyme Complexes/metabolism , Proteasome Endopeptidase Complex/metabolism , Rats , Rats, Wistar , Spleen/enzymology , T-Lymphocytes/immunology , T-Lymphocytes/metabolism , Time FactorsABSTRACT
The level of natural apoptosis in rat thymus on day 18 of embryo development attained 25%, while at subsequent terms it was about 5%. In the spleen, this parameter gradually decreased from 15 to 37% starting from day 18 of embryo development to postnatal day 30. Tactivin prevented the development of dexamethasone-induced apoptosis in thymocytes of 30-day-old rats, but had no effect on spontaneous apoptosis. Tactivin can be used as a modulator of apoptotic processes.
Subject(s)
Adjuvants, Immunologic/metabolism , Apoptosis/drug effects , Dexamethasone/toxicity , Peptides/metabolism , Thymus Extracts/metabolism , Thymus Gland , Animals , Cells, Cultured , Rats , Spleen/cytology , Spleen/drug effects , Thymus Gland/cytology , Thymus Gland/drug effectsABSTRACT
The levels of spontaneous apoptosis and proliferation of the rat thymic and spleen cells, as well as their regulation by the hypothalamo-hypophysial system were studied during perinatal development. The apoptotic and proliferating cells in the thymus and spleen were assayed using flow cytometry with the DNA-specific dye propidium iodide. The level of apoptosis in the thymus reached 25% on day 18 of embryogenesis (E 18) and decreased to 5% thereafter. In the spleen, the level of apoptosis gradually increased from 15 to 37% during the period of E18 to day 30 of postnatal development (P30). The level of dividing cells in the thymus was 20-25% at all developmental stages studied. In the spleen, it was at a maximum on E18 (32%) and decreased almost twice on E21 (17%). On P7, the amount of proliferating cells again increased to 22% and then gradually decreased to 7% by P30. The surgical ablation of hypothalamus in utero on E18 did not affect cell apoptosis or proliferation in the thymus and spleen. The surgical ablation of both hypothalamus and pituitary led a twofold decrease of the level of apoptosis in the spleen and insignificant increase of the level of proliferation in the thymus. Thus, the numbers of cells in the embryonic thymus is regulated not only by the thymus itself, but also by the hypothalamo-hypophysial system. The programmed cell death in the embryonic spleen appears to be regulated by the hypothalamo-hypophysial system as well.
