Adaptive Immunity

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Adaptive Immunity
2015-09-17 19:09:31

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  1. —Works together with inflammation. Recognizes foreign or “nonself” substances. Provides Long term protection. Slower than innate but more specific. has memory
    Adaptive immunity
  2. –Pathogens– Noninfectious environmental agents –Drugs –Vaccines– Transfusions Transplants
  3. —End-products of adaptive immunity Lymphocytes:
    T and B cells
  4. End-products of adaptive immunity: Antibodies
    Immunoglobulins (Ig)
  5. ◦Each individual T or B cell specifically recognizes only one particular antigen. ◦Sum of the population of lymphocyte specificities may represent millions of foreign antigens.
    Generation of clonal diversity
  6. Primary Lymphoid organs (2)
    thymus for T cells and bone marrow for B cells.
  7. Occurs in primary lymphoid organs. Involves the maturing of B and T cells. Migrates to secondary lymphoid organs.
    Clonal diversity
  8. Antigen is processed and presented to immune cells by antigen-presenting cells (APCs). Cellular interaction of T-helper cells (Th) and APCs. –Results in the differentiation of B cells into active antibody-producing cells and T cells
    clonal selection
  9. B cells turn into Active antibody producing cells also called
    plasma cells
  10. T cells turn into
    Effector cells
  11. B cells and circulating antibodies are the primary cells. Causes direct inactivation of a microorganism or the activation of inflammatory mediators. Primarily protects against bacteria and viruses.
    Humoral Immunity
  12. ◦Differentiates T cells. Primarily protects against viruses and cancer. Kills targets directly or stimulates activity of other leukocytes.
    cell-mediated immunity
  13. Humoral and cellular immunity work together to provide ____ and ____. Respond more rapidly and efficiently on subsequent exposure to the same _____
    immunity and memory

  14. Antibodies or T cells are produced after either a natural exposure to an antigen or after immunization. Is long lived.

    active or passive immunity
  15. Preformed antibodies or T lymphocytes are transferred from a donor to a recipient. Occurs naturally or artificially. Is temporary or short lived.

    active or passive immunity
  16. —required for a successful immune response.— Are complicated processes and involve a highly effective interaction of cells.
    recognition and response
  17. Originally was used to describe proteins found on the surface of lymphocytes. Currently used as a labeling system used to identify a family of proteins on many cells.
    clusters of differentiation
  18. —Is a molecule that can react with antibodies or receptors on B and T cells.— Is mostly protein but can be other molecules as well.
  19. —An antigen that can trigger an immune response
    Immunogenic antigen
  20. Antigen’s binding site: antigenic determinant
  21. Antibody or lymphocyte’s binding site: Antigen-binding site
  22. Degree to which antigen has _____ capability is degree of foreignness to host (most important), size, chemical complexity, amount
  23. Small–molecular-weight antigens are called_____. –Cannot trigger the immune response themselves but can when bound to a carrier protein.
  24. –The greater the diversity, the more the immunogenicity. dealing with Antigen
    chemical complexity
  25. ––antigens in High or low extremes can cause tolerance.
  26. —We recognize ourselves as not foreign.
  27. Lymphocytes with receptors against self-antigens are eliminated.
    central tolerance
  28. Prevents recognition by lymphocytes and antibodies.
    peripheral tolerance
  29. antibodies are also called
  30. antibodies are produced by
    plasma cells
  31. Antibodies have several classes –characterized by antigenic, structural, and functional differences. (5)
    ◦IgG, IgA, IgM, IgE, and IgD
  32. Is the most abundant class (80% to 85%). Is transported across the placenta. Accounts for most of the protective activity against infections. most prevalent. Most protective activity against infection. Crosses placenta. most prevalent

    ◦Four classes: IgG1, IgG2, IgG3, and IgG4.
  33. in body secretions are dimers anchored by the J-chain and “secretory” piece.– Secretory piece may function to protect ___ against enzyme degradation.
  34. type of IgA that is predominantly in the blood
  35. Type of IgA predominantly in normal body secretions.
  36. Is the largest of the immunoglobulins. Pentamer is stabilized by a J-chain. Is the first antibody produced during the primary response to an antigen. Is synthesized during fetal life.
  37. Information limited. Concentration is low in the blood. Is located primarily on the surface of developing B lymphocytes. Functions as one type of B-cell antigen receptor.
  38. Is the least concentrated of the immunoglobulin classes in the circulation. Acts as a mediator of many common allergic responses. Defends against parasites.—
  39. Antibody molecular structure: Acts as recognition sites (receptors) for antigenic determinants; binds antigen; has two identical fragments.
    Antigen-binding fragment (Fab)
  40. Antibody molecular structure: Is responsible for biologic function.– Activates complement and opsonization.
    crystalline fragment (Fc)
  41. Antibody molecular structure: Two light chains and two heavy chains are held together with disulfide bonds.– Heavy chain determines the type of antibody.
    polypeptide chains (4)
  42. —Amino acid sequences of the variable regions of the heavy and light chains—. Framework regions that control antibody folding
    antigen binding
  43. ◦Noncovalent chemical interactions
    lock and key
  44. IgG, IgD, circulating IgA and IgE—2 Secretory IgA—4 IgM—theoretically 10, likely 5

    number of binding sites
    antibody valence
  45. —Is located on the surface of B cells.
    B cell receptor complex
  46. –Membrane-associated IgM and IgD. –Responsible for recognition and binding
    antigen-recognition molecules
  47. –Ig-alpha and Ig-beta heterodimers–. Responsible for sending message to mature and to make antibodies
    Accessory intracellular-signaling molecules
  48. Antibody-like transmembrane protein (TCR)–. Are responsible for recognition and binding. Accessory proteins for intracellular signaling. –Are referred to as CD3. –Are responsible for sending message to activate and differentiate T cells.
    T cell receptor complex
  49. —Are needed for an effective immune response.— Antigen is processed within cells.— Are expressed on the cell surface in a specific manner.— Some antigens need special APCs; others can be processed by most any type of cell.
    molecules that present antigen
  50. ◦Glycoproteins on the surface of all human cells (except red blood cells [RBCs])◦Human leukocyte antigens (HLA) alleles: Inherited in a co-dominant fashion to enable both maternal and paternal antigens to be expressed ◦Are also called HLAs◦MHC class I genes: A, B, and C◦MHC class II genes: DR, DP, and DQ◦MHC class III genes: Other genes that control the quality and quantity of an immune response
    Major histocompatibility complex (MHC)
  51. —Is a specific combination of alleles at the six major HLA loci on one chromosome (A, B, C, DR, DQ, and DP).
  52. —Cells in transplanted tissue from one individual have a different set of MHC surface antigens than those of the recipient. —The recipient can mount an immune response against foreign MHC molecules. —The more similar two individuals are in HLA tissue type, the more likely for a successful transplant.
  53. —Antigen-presenting molecules. —Found on APCs and thymus cells. —Present lipid antigens◦(Mycobacterium tuberculosis and Mycobacterium leprae)
  54. —Antigen-independent interactions between cells. —Resulting in intracellular signaling events that are independent of the TCR or BCR complexes. —Necessary complement to antigen-specific signaling. —Needed for effective immune response.
    molecules that hold cells together
  55. —Low–molecular-weight proteins, or glycoproteins, function as chemical signals between cells. Are secreted by APCs and lymphocytes.
    Cytokines and their receptors
  56. Cytokines increase the production of
  57. Influences given cell that ultimately determines that cell's response. lymphocytes proliferate and differentiate in result.
  58. —All necessary receptor specificities are produced.— Takes place in the primary (central) lymphoid organs. Thymus for T cells, bone marrow for B cells—. Results in immature but immunocompetent T and B cells.— Migrates to secondary lymphoid organs to wait for antigens. Primarily occurs in the fetus
    generation of clonal diversity
  59. —Usually beings at birth and proceeds throughout life. —Is a process by which antigen selects lymphocytes with complementary TCRs or BCRs.
    clonal selection
  60. initiated by antigen. Expands the population and causes differentiation into antibody-secreting plasma cells or mature T cells or both.
    clonal selection
  61. Deoxyribonucleic acid (DNA) is cut and spliced. Each cell is unique and able to react with different antigens.
    somatic recombination
  62. central lymphoid organ of T-cell development.
  63. —T cells move from the thymic cortex to the medulla.— Changes include the development of the TCRs and the expression of surface molecules. —T cells are released into the blood and take up residence in the secondary lymph organs to await antigens.
    T-Cell Maturation
  64. —Produce changes in characteristic surface markers (TCR, CD4, CD8)
    T cell maturation
  65. CD2 is a marker for
    t cells
  66. recognize antigens presented by MHC class II molecules and develop into Th cell
    CD4 cells
  67. recognize antigens presented by MHC class I molecules and become mediators of cell-mediated immunity and directly kill other cells (T-cytotoxic [Tc] cells).
    CD8 cells
  68. Autoreactive T cells in the thymus are deleted
    Central tolerance
  69. ◦A TCR strongly reacts with MHC class I or class II; the T cell will undergo apoptosis.
    clonal deletion
  70. ◦Developing T cell’s TCR binds strongly with a self-antigen causing T cell to be deleted.
    negative selection
  71. ◦Surface CD4 molecules bind to MHC class II molecules and become CD4 single–positive; surface CD8 reacts with MHC class I molecules and become CD8 single–positive. –60% of immunocompetent T cells being CD4+ and 40% being CD8+.
    positive selection
  72. —Occurs in the bone marrow.— Stem cell matures. ◦CD45R and the interleukin (IL)–7 receptor–IL-7: Is produced by stromal cells; is critical in driving the further differentiation and proliferation of the B cell.
    B cell maturation
  73. —Production of BCRs. Heavy and light chains. V, D, and J genes
    Production of BCRs
  74. Complement receptor
    CD 21
  75. ◦Adhesion molecule required for later interactions with Th cells
  76. ◦Large number of autoreactive B cells are eliminated if exposed to self-antigen—over
  77. —Include the spleen, lymph nodes, adenoids, tonsils, Peyer patches (intestines), and appendix.
    secondary lymphoid organs
  78. —Lymphocytes bind to the endothelium through adhesion molecules.
    high endothelial venules
  79. Antigens require processing and presentation by
  80. –Present antigen to Th cells that facilitate humoral immune response
    B lymphocytes
  81. Present antigen to memory Th cells to initiate a rapid response to antigens
    secondary immune response, macrophages
  82. –Process antigen from a site of inflammation to T-cell–rich areas of lymph nodes
    dendritic cells
  83. ◦Antigen processing: Is the process by which exogenous and endogenous antigens are linked with the appropriate ___ molecules.
  84. ◦Generally present endogenous (inside cells) antigens.
    class 1 MHC molecules
  85. ◦Prefer exogenous (outside cells) antigens.
    class 2 MHC molecules
  86. —Th cells help the antigen-driven maturation of B and T cells.—Facilitate and magnify interaction between APCs and immunocompetent lymphocytes.
    T-helper lymphocytes