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ComplementProtective factorsActivated T and B lymphocytesCytokines AND Antibodies
DIFFERENCE BETWEEN CELL MEDIATED & HUMORAL T-CELLSor T-LYMPHOCYTES: come from Lymphoid Stem cells in the bone marrow. They migrate and further mature in the THYMUS. They are considered immunocompetent but are still not fully mature cells. They migrate toSpleen or Lymph nodes (or other secondary lymphoid organs) where they remain dormant until activated to undergothe 2ndphase of maturation.2ndphase of maturation= Clonal Selectionoccurs after they are stimulated by an Antigen Presenting Cell to furtherdifferentiate into a T-Cell with specific receptors for a specific antigen. (antigen presenting cell can be almost any cell that can process a given antigens inside the cell and then display a “marker” or /antigen-specific receptor on its surface that attracts the attention of the T-cells or other immune cells.Cell-Mediated immunity is that Immunity conferred by a variety of T-Cells with various functions. Immunity is active against cells infected with intracellular Bacteria or Viruses. It defends against:fungal parasitic infections tumorsresponsible for organ transplantation rejection.T-Cells or T-Lymphocytes, come in different varieties and are classified by “cluster of differentiation” CD for short. We need to know 4types for the test. Some are commonly known by several names.T-HELPER CELLS (CD4 /T4cells) (HELPERS) *Important * many functionsThis group of T cells helps the antigen-driven maturation of both B & T cells. They perform this task by facilitating & magnifying the interaction between APCs (antigen presenting cells) & the immune-competent lymphocytes.ACTIVATESomacrophages oB-cells, (activate B-cells with chemical messengers CYTOKINES to mature into plasma cells that can produce antibodies)oCytotoxic T-cellsoother T-helper/CD4 cells.RELEASESolymphokines that begin the inflammatory process. oSubgroups of the T-helper cells/CD4 cells like, TH1 and TH2, release the lymphokines. *in lecture notes* MEDIATES oMediates delayed hypersensitivity reactions such as the TB skin test. *from lecture notes*CYTOTOXIC-T CELLS- (Cytotoxic cells/ CD8/T8cells/ T-killers/Tc)KILLS: Releasing cytotoxic chemicals that destroy the cell membraneOr inducing apoptosis ovirus infected cellsotumor cells oallograft cells (transplant tissue) (from his lecture)*Memory T-cells*: not on his outline organizer but in his lecture( page2) allow the host to remember antigens and respond quicker and more vigorously after the initial exposure. They live for many years and* can reproduce themselvesT-regulatory cells: slow or stopthe immune response after invader is destroyed