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Unformatted text preview: Antigenic determinants Antigen Antibody B Antibody C Figure 21.7 MHC: major histocompatability
complex Cell external surfaces have protein molecules,
termed self antigens
termed Glycoproteins mark cells as self Each MHC is different for each individual Class I: found on all cells Class II: only certain cells acting in immune
response Cells of the immune system
Cells Three cell types Lymphocytes T – cells: non-antibody-producing, cell
mediated B – cells: humoral immunity Antigen-presenting cells (APC): no
specific antigens, but play an auxiliary role
Lymphocytes Maturation depends on the cell becoming
Maturation immunocompetent: able to recognize and bind
to an antigen
to T-cells: 2-3 day process to mature (under
T-cells: thymus hormones) to identify foreign antigens
thymus Positive selection: recognize own tissues when bound
to an antigen
to Negative selection: bind to self-proteins Must become self-tolerant, unresponsive to selfantigens T cell selection in the thymus
T cell selection in the thymus Lymphocytes
Lymphocytes B-cells: in bone marrow, but little is known
about the factors controlling maturation
about Immunocompetence in organs that
activate lymphocytes termed primary
lymphoid organs. All other lymphoid
organs are secondary lymphoid organs.
organs Adaptive defenses Immature
lymphocytes Red bone marrow: site of ly...
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This note was uploaded on 04/11/2013 for the course BIOL 361 taught by Professor Unkown during the Spring '12 term at University of Texas at Austin.
- Spring '12