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1	Cbx4 regulates the proliferation of thymic epithelial cells and thymus function Liu, B., Liu, Y. F., Du, Y. R., Mardaryev, A. N., Yang, W., Chen, H., Xu, Z. M., Xu, C. Q., Zhang, X. R., Botchkarev, V. A., Zhang, Y., Xu, G. L. January 2013 (has links) Thymic epithelial cells (TECs) are the main component of the thymic stroma, which supports T-cell proliferation and repertoire selection. Here, we demonstrate that Cbx4, a Polycomb protein that is highly expressed in the thymic epithelium, has an essential and non-redundant role in thymic organogenesis. Targeted disruption of Cbx4 causes severe hypoplasia of the fetal thymus as a result of reduced thymocyte proliferation. Cell-specific deletion of Cbx4 shows that the compromised thymopoiesis is rooted in a defective epithelial compartment. Cbx4-deficient TECs exhibit impaired proliferative capacity, and the limited thymic epithelial architecture quickly deteriorates in postnatal mutant mice, leading to an almost complete blockade of T-cell development shortly after birth and markedly reduced peripheral T-cell populations in adult mice. Furthermore, we show that Cbx4 physically interacts and functionally correlates with p63, which is a transcriptional regulator that is proposed to be important for the maintenance of the stemness of epithelial progenitors. Together, these data establish Cbx4 as a crucial regulator for the generation and maintenance of the thymic epithelium and, hence, for thymocyte development. Animals Bromodeoxyuridine Cell Proliferation Epithelial Cells/metabolism/physiology Flow Cytometry Gene Targeting Histological Techniques Immunoprecipitation Mice Microscopy, Fluorescence Organogenesis/physiology Phosphoproteins/metabolism Real-Time Polymerase Chain Reaction T-Lymphocytes/cytology Thymus Gland/cytology/embryology Trans-Activators/metabolism Ubiquitin-Protein Ligases/*metabolism REF 2014
2	Effect of Moderate Exercise on Proliferative Responses of Peripheral Blood Mononuclear Cells Smith, J, Chi, D, Salazar, S, Krish, G., Berk, S., Reynolds, S., Cambron, G. 01 June 1993 (has links) We studied the effects of 30 minutes of exercise on T lymphocyte counts and proliferative responses of peripheral blood mononuclear cells (PBMC) in 25 runners. Exercise resulted in a T lymphocytosis in the immediate post-exercise period in all subjects (p < 0.001), and reduced CD4+/CD8+ ratios in 22/25 subjects (p = 0.001). The change was due primarily to a 2.2-fold increase in CD8+ cells (p < 0.001). Exercise also reduced PBMC mitogenic responses to phytohemagglutinin (PHA) in 13/14 subjects (p = 0.049), and to pokeweed mitogen (PWM) in 11/14 subjects (p = 0.022), but not to concanavalin A. Postrun sera from 5 of 6 subjects inhibited PHA but not PWM responses of resting autologous PBMC with normal CD4+/CD8+ ratios (p < or = 0.05): indomethacin and monocyte depletion blocked the serum inhibition (p = 0.003, p = 0.0006, respectively). We conclude that post-exercise suppression of mitogenic responses to PHA is due to the release of a serum factor(s) capable of inducing prostaglandin synthesis by circulating monocytes, whereas exercise-induced suppression of PWM responses depends primarily on the reversal of CD4+/CD8+ ratios. adult CD4-CD8 Ratio CD4-Positive T-lymphocytes (cytology physiology) concanavalin A (pharmacology) exercise (physiology) female humans indomethacin (pharmacology) leukocyte count leukocytes mononuclear (cytology physiology) lymphocyte activation (physiology) male middle aged phytohemagglutinins (pharmacology) pokeweed Mitogens (pharmacology) T-lymphocytes cytotoxic (cytology physiology) QCOM

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Cbx4 regulates the proliferation of thymic epithelial cells and thymus function

Effect of Moderate Exercise on Proliferative Responses of Peripheral Blood Mononuclear Cells