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با نام و یاد خدا. Interferons. Type I( ,), Autocrine and paracrine Cause sequestration of lymphocytes Promote diff. naïve T cells Increase cytotoxicity of NK and CTLs Upregulate expression MHC-I Treatment of some tumors. Cells and Tissues of the immune system.
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Interferons Type I(,), Autocrine and paracrine Cause sequestration of lymphocytes Promote diff. naïve T cells Increase cytotoxicity of NK and CTLs Upregulate expression MHC-I Treatment of some tumors
Cells and Tissues of the immune system • The cells of the adaptive immune system are normally present: a)Circulating cells in the blood and lymph b)Anatomically defined collection in lymphoid organs c)Scattered cells in all tissues
Lymphocytes Antigen presenting cells(APC) Effector cells
Cells of the immune system (lymphocytes) • Lymphocytes are the only specific cells and are responsible for specificity and memory • They are 3 subsets ,different in functions and protein products but not in morphology 1-B cells 2- T cells(helper and cytotoxic) 3- Natural killer (NK) cells
B lymphocyte development stem cell Pro B cells CD19,CD10, µ heavy chain rearrangement Pre B cells Pre antigen receptor expression immature B cells IgM BCR expression,independent of antigen and their encounter with it ,receptor editing,cell death,functional unresponsiveness Mature B cells
B cell surface markers • B cell receptor(Ag recognition) • CD19 (B cell activation) • CD21or CR2 (B cell activation and EBV receptor) • CD25 (binds IL- 2) • CD27 (memory B cells ) • CD40 (B cell activation) • CD80 or B7(costimulator for T cell activation) • CD81 (B cell activation)
T cell subpopulations T lymphocytes mature in the thymus *Mature T cells :Th and Tc,TR *T cells have CD4, CD8,TCR(αβ & ) ,CD28,CD40L,CD2,CTLA-4(memory T cells have IL-7 R) *T helper cells have 2 subsets :Th1 and Th2 are differentiate by cytokine pattern that they produce. *Th1=IFN- *Th2 =IL-4 , IL-5,IL-10, IL-13
Effector cells • Activated Th cells • Cytolytic T cells • Plasma cells • Mononuclear phagocytes • Nk cells
Dendritic cells Coventional Dc Plasmacytoid Dc