Micro J210 Adaptive Immunity

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Micro J210 Adaptive Immunity
2011-02-27 16:57:38
Micro J210 Adaptive Immunity

Micro J210 Adaptive Immunity
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  1. What is adaptive immunity?
    -The body's abilitiy to recognize and defend itself against distince invaders and their products
  2. What are the five attributes of adaptive immunity?
    • -Specificity
    • -Inducibility
    • -Colonality
    • -Unresponsiveness to self (tolerance)
    • -Memory
  3. What are the two types of adaptive immune response?
    • -Humoral immue responses
    • -Cell-mediated immune responses
  4. What are the two main types of lymphocytes in adaptive immunity?
    • -B lympocytes (B cells)
    • -T lymphocytes (t Cells)
  5. What is an overview of adpative immunity?
    • There is a T Helper cell that will either
    • 1. Tell B cells to release antibodies
    • 2 Use cytokines to get T cytotoxic cells to work
  6. What is the lymph system?
    • -Lymphatic vessels, cells, tissues, and organs that screen the tissues of the body for foreign antigens.
    • -The flow of lymph, one-way system that conducts lymph from tissues and returns it to the circulatory system
  7. What is lymph?
    • -Liquid with similar comnposition to blood plasma
    • -Arises from fluid leaked from blood vessels into surrounding tissues
  8. What are the primary organs of the lymphatic system?
    • -Red bone marrow
    • -Thymus
    • Where cells undergo maturation
  9. What are secondary lymph organs?
    • -Where matured cells reside and function
    • -Lymph nodes
    • -Spleen
    • -Tonsils
    • -Mucosa-Associated lymphatic tissue (MALT)
  10. What are lymph nodes?
    • -Small, bean- shaped structures in the body that are part of the lymph system.
    • -Found singly or in groups, may be small or large.
    • -Can be felt in neck, groin, and underarms
    • -When a part of the body is infected, nearby lymph nodes can be swollen
  11. What are properites of antigens?
    • -Molecules that the body recognizes as foreign and worthy of attack
    • -Recognized by 3D regions called epitopes (8 amino acid long)
    • -Include bacterial components, proteins of virus, fungi, and protozoa
    • -Food and dust have antigenic particles
    • -Antigens provoke a specific immune response
  12. What are Exogenous antigens?
    • -Antigens that have entered the body from the outside, by inhalation, ingestion, or injection
    • -These are broken up or presented to T cells
  13. What are endogenous antigens?
    • -Antigens that have been generatedc within previously normal cells as a result of normal cell metabolism or because of viral or intracellular bacterial infection.
    • -Virus has non cell antigen
  14. What is a autoantigen?
    Usuallly a normal protein or complex of proteins
  15. What is a pluripotent stem cell?
    -When cells of blood orginate from one common stem cell
  16. What are B cells?
    • -Arise and mature in red bone marrow
    • -Found in spleen, lymph nodes, and MALT
    • -Small % circulate in blood
    • -Major function is secretion of antibodies
  17. What is a BCR?
    • -B-cell receptor, has specificity.
    • -Each B cell generates a single BCR
    • -Two variable regions of teh BCR form the antigen-binding sites
    • -The entire repertoire of an individuals BCRs is capable of recognizing millions of different epitopes.
    • -Grabs the antigen
    • -Has a constant area and variable is where antigen is attached, and is attached to the cell
  18. What happens when a B cell gets stimulated?
    -The antigen stimulates a B cell and it releases immunoglobulins.
  19. What is the shape of an antibody?
    -Y shape, with a variable area for antigens to attach and then a costant middle.
  20. What are antibodies?
    • -Specificity
    • -Antibodes are immunoglobulins similar to BCRS
    • -Secreted by activated B cells called plasma cells
    • -Have identifcal antigen-binding sites and antigen specificty as the BCR does
  21. What is the function of an antibody?
    • -Antigen-binding sites are complementary to epitopes (lock and key)
    • 6 functions:
    • 1. Activation of complement and inflammation
    • 2. Neutralization
    • 3. Opsonization- the sauce, better for PMN to get
    • 4. Agglutination- clumping
    • 5. Killing by oxidation
    • 6. Antibody-dependent cellular cytotoxicity (ADCC) NK cells kill easier with coating
  22. How does a flu shot work?
    By neutralization so it cant bind to cells
  23. What is important about the classes of antibodies?
    • -threats confronting the immune system are variable
    • -Class involved in immune response depends on the type of antigen, portal of entry, and antibody function needed.
  24. What are the five classes of antibodies?
    -IgM, IgG, IgE, IgA, IgD
  25. What is IgM?
    • First antibody produced
    • Largest
    • Pentameric (five)
  26. What is IgG
    • -Most common and longest-lasting antibody
    • -in serum
    • -Can cross the placenta because its the smallest
  27. What is IgA?
    • Associate with body secretions
    • Dimeric
    • Protective secretions
  28. What is IgE?
    Involved in reponse to parasitic infections and allergies
  29. What is IgD?
    -Exact function not known
  30. What is a T Cell?
    • Produced in bone marrow, but matures in Thymus
    • Only about 4/100 are mature
    • -Circulate in the lymph and blood and migrate to lymph nodes, spleen, and peyer's patches
    • -Antigen-binding sites are complementary to epitopes
    • -Have T cell receptors (TCR) on their cytoplasmic membrane.
  31. What is a naive T cell?
    -one that has not incountered any antigen
  32. What is a TCR?
    • T cell receptor
    • -Does not bind directly to the antigen
    • -Specificity
    • -Does not recognize epitopes directly
    • Oly bind epitops associated with a MCH protein
    • -Act against cells that harbor intracellular pathogens
    • -Cannot get secreted
    • -Shape is like two poles with variable then a constant regions, made of carbs, and a disulfide bond
  33. What is a APC?
    Antigen presenting cell
  34. How does APC work?
    The APc stimulates T cells to become helper cell, which stimulates B cells and uses cytokines to get help from T cytotoxic cell
  35. How do you type T lymphocytes?
    - Based on surface glycoproteins and characteristic functions
  36. What are the three types of T lymphocytes?
    - Cytotoxic, Helper, and regulatory
  37. What is a cytotoxic T cell?
    • -Directly kills other cells (virally infected cells)
    • -CD8+
  38. What is a helper T cell?
    Helps regulate the activates of B cells and cytotoxic t cells
  39. What is a regulatory T cell?
    Represses adaptive immune responses
  40. What is the clonal selection theory?
    Induction of a certain antigen which causes proliferation and leads to effector memory
  41. What is the clonal deletion of auto-reactive B cells?
    • -It is vital that immune response not be directed against autoantigen
    • -Body elimiantes self-reactive lymphocytes
    • -The immature B cells whose BCR bind too strongly to self antigens, will not mature
    • -If B cells are found to be highly reactive to self they are idcued to undergo apoptosis
  42. What is the clonal deletion of auto-reactive T cells in thymus?
    During maturation in the thymus, T cells that react to autoantigens are eliminated by being induced to undergo apoptosis
  43. What are cytokines?
    • -Cells of immune system communicate by releasing soluble regulatory proteins that act on other cells
    • -Secreted by various leukocytes
    • -The complex web of signals among all the cells of teh immune system is called cytokine network
  44. What are interleukins (ILs)?
    • Cytokine of the immune system
    • -Signal among leukocytes
  45. What are Interferons (IFNs)?
    • Cytokine of the immune system
    • -Antiviral proteins that may act as cytokines
  46. What are growth factors?
    • Cytokine of the immune system
    • -Proteins that stimulate stem cells to divide
  47. What are Tumor necrosis factor (TNF)?
    • Cytokine of the immune system
    • -Secreted by macrophages and T cells to kill tumor cells and regulate immune responses and inflammation
  48. What are chemokines?
    • Cytokine of the immune system
    • Chemotactic cytokines that singal leukocytes to move
  49. Does each cell have a different receptor for different cytokines? and can it produce more than one type of cytokine?
    Yes and yes
  50. What is the Major Histocompatibility complex?
    • -MHC
    • -Group of antigens 1st identified in graft patients
    • -Important for determining compatiability of tissues for tissue grafting
    • -Major histocompatibility antigens are glycoproteins found in the membranes of most cells of vertebrate animals
    • -Hold and postion antigenic determinants for presentation to T cells
    • Antigens bind in the groove of MHC molecules
  51. What is MHC Class 1?
    - Present on the surface of all nucleated cells in the body
  52. What is MHC class II?
    -Present on the surface of all professional antigen presenting cells aka macrophages
  53. What are examples of profesional antigen presenting cells?
    -Dendritic cells, macrophages and B cells
  54. What are dendritic cells?
    • -Antigen that enters the skin is loaded on dendritic cells, which migrate to draing lymph nodes. In the lymph nodes, naive T cells are activated by antien-loaded dendrici cells and start to proliferate and differentiate
    • -These antigen-responisve cells acquire expression of specific adhesion molecules and chemokine receptors that enable them to migrate to the effector site.
    • -On all CT graft, sees the antigen and presents to T cell
  55. What is antigen processing?
    • -Antigens processed for MHC proteins to dispaly epitopes
    • -Different processes for endogenous and exogenous antigens
    • Endogenous- MHC I
    • Exogenous- MHC II
  56. What is cell-mediated immune response?
    • -Reespond to intracellular pathogens and abnormal body cells
    • -Most common is intracellular pathogens are viruses
    • -The response is also effective against cancer cells, intracellualr protozoa, and intracellular bacteria.
    • -The cell is infected, expresses virus antigen, T cell comes and kills that cell
  57. What is the activation of T cell clones?
    • -Cytotoxic T cells
    • -Antigen presentation by APC MHC II
    • -Helper T cell differentiation
    • -Clonal expansion- IL-2R
    • -Self-stimulation
    • MHC I
  58. What is cytoxic lymphocytes serial killing?
    -Kills virally infected cells. T cell recognizes by epitopes, after MHC I, then caues infected cell to apoptosis and macrophages clean up the mess
  59. What are memory t cells?
    • -Some activated T cells become memory T cells
    • -Persist for months or years in lympoid tissue
    • -immediately functional upon subsequent contacts with epitope specific to its TCR
    • -Ex. vaccinations
  60. What is a humoral immune response?
    • -Against exogenous pathogens
    • -Is activation of B cells which release Immunoglobulins
    • -T dependent and T indenpendent of B cells
  61. What is T dependent activation of B cells/
    • -B and T cells that have not yet recognized an antigen via their BCR/TCR are called naive lymphocyes
    • -Most protein antigens that activate naive B cells are called T dependent antigens. The B must first interact with effector T4 lymphocytes before they have a response
  62. What happens after the T4 is presented to the B cell?
    • -It relaese cytokines that actiate B cells to proliferate into antibody-secreting B cells and plasma cells
    • -Some B cells differentiate into B memory cells for heightened 2nd response against antigen
  63. What are plasma cells?
    • -Majority of cells produced during B cell proliferation
    • -Only secrete antibody molecules complementary to the specific antigen
    • -Short lived cells that die within a few days of activation-their antidies and progeny can persist
  64. What are memory B cells?
    • - T depedent
    • -Immunological memory
    • -Produced by B cell proliferation but no not secrete antibodies
    • -Have BCRS complementrary to teh antigenic determinatnt that triggered production
    • -Long lived cells that persist in lymph tissue
    • -Initiates antibody production if antigen is encountered again
    • -Form at first exposure
  65. What is the binding of T-independent antigen by a B cell?
    • -t independent antigens are antigens which can directly stimulate B cells to produce antibody without T cell hep in general.
    • -Polysaccharides are T-independent antigens
    • -These antigens are characterized by the same antigenic determinant repeated many times (has same epitope)
    • -Faster response
    • -This is lacking in children, so do not give them polysacchoride vaccine
  66. What is a primary response?
    - IgM then after 5 days IgG goes up then back down after 15 days
  67. What is a secondary response?
    -IgM and IgG both high on day 3, IgM goes downn day 6, but IgG stays high because of memory B cells
  68. What is acquired immunity?
    -Specific immunity acquired during an individuals life
  69. What are two types of acquired immunity?
    • -Naturally: response against antigens encountered in daily life
    • -Artifically: response to antigens introduced via vaccine
    • Can be active or passive (antibodies from antoehr indiviudal animal or human)