Immuno - Lecture 1 - 2

  1. What is the main function of Regulatory T cells? INNATE IMMUNITY includes what?
    • Physical Barriers
    • Cellular Barriers
    • Chemical Barriers
  2. What are the Features of Innate Immunity?
    • First Line of Defense
    • Present on Birth
    • Non-specific
    • Resistance not improved by repeated infections
    • Physiological Barriers
    • Phagocytosis, Inflammation, Fever
  3. What are the characteristics of the Adaptive/Acquired Immunity?
    • Resistance improves after repeated infections
    • Cells involved include B lymphocytes, T lymphocytes and Macrophages
    • Primary and secondary lymphoid organs are involved in the process
  4. What is an IMMUNOGEN?
    Any agent inducing an immune response
  5. What are the characteristics of an immunogen?
    • Foreignness
    • High Molecular Weight
    • Chemical Complexity
  6. What is an Antigen?
    Any agent capable of binding specifically to components of immune response
  7. What are the antigens composed of?
    • Carbohydrates
    • Lipids
    • Nucleic Acids
    • Proteins
  8. What are Antibodies?
    Soluble globulin proteins
  9. What are the characteristics of antibodies?
    • Specificity
    • Distinct biological activity
    • Four chain structure: two identical light and two identical heavy chains
    • Three fragments of equal sizes
    • Fab fragment
    • Fc fragment
  10. What are the Functions of IgG?
    • Agglutination , precipitation and opsonisation
    • Conferral of immunity to fetus
    • ADCC
    • Activation of complement
    • Neutralization of toxins and viruses
    • Immobilization of bacteria
  11. What are the Properties of IgM?
    • Pentamer molecule
    • Synthesized after immunization
    • Elevated levels levels indicate recent infection
    • Synthesized by placenta and elevated levels in fetus indicative of congenital infection
    • Best agglutinating and complement-activating antibody
  12. What are the properties/functions of IgA?
    • Major immunoglobulin in secretions
    • Monomeric as well as Diameric
    • Role in Mucosal infections
    • Bactericidal Activity
    • Antiviral Activity
  13. What are the properties/functions of IgD?
    • Causes the differentiation of B cells to a more mature form
    • Present on the surface of B lymphocytes
    • Present in monomeric form
  14. What are the properties/functions of IgE?
    • Reaginic antibody
    • Protects against parasites
    • Important role in hypersensitivity
  15. How do Primary and Secondary Antibody Responses differ?
    • Time course; secondary response has a shorter lag phase and an extended plateau and decline
    • Antibody titer: greater in secondary response
  16. What are the LYMPHOID CELLS?
    • T cells: develop in the thymus
    • B cells: differentiate in fetal liver and adult bone marrow
    • NK cells: does not possess T cell or B cell receptors
  17. What are the characteristics of T Cells?
    • The definitive T cell marker is the cell antigen receptor (TCR)
    • TCR-1 (Composed of ϒ and Ϭ chains, 5%)
    • TCR-2 (Composed of α and β chains, 95%)
    • Both receptors are associated with a complex of polypeptides making up the CD3 complex.
  18. The TCR-2 cells are divided into two major subsets, what are they?
    • CD4+ (Helper T cells)
    • CD8+ (Cytotoxic T cells)
  19. CD4+ (Helper T cells) TCR-2 cells are divided into what subgroups?
    • CDw29+ (positively influence the immune response of T cells and B cells-the helper function)
    • CD45R+ (Induce cytotoxic function in CD8+ cells)
  20. Their principal functions include a negative feedback after the generation of an immune response and to protect from autoimmunity.
  21. CD4+ T cells mediate ________________independent of CD8+ T cells.
    suppressor function
  22. ____________ maintain self tolerance and suppress responses to foreign antigens.
    Regulatory T-cells
  23. ______________T cells are mature T cells with a distinct regulatory function.
    CD4+CD25+
  24. What are the main Regulatory T cells?
    • CD4+ CD25+ T cells,
    • peripheral Treg cells,
    • IL-10 secreting Tr1 cells
    • TGFβ secreting TH3 cells,
    • CD8+CD28- T cells, CD8+CD122+ T cells, Qa-1-restricted CD8+ T cells,
    • γ/δ T cells
  25. What are the features of Memory T cells?
    • Memory T cells persist even after the invading pathogen has been eliminated.
    • There are two types of memory T cells, central memory T cells and effector memory T cells.
    • They are either CD4+ or CD8+ and respond quickly after they see the antigen at a second time.
  26. What are the features of NKT cells?
    • They perform cytotoxicity and mostly are not MHC-restricted.
    • They recognize antigens which are glycolipids and require CD1d.
    • They release cytokines including IL-4, IFN-γ, GM-CSF. and others.
  27. What are the features of NKT cells?
    • NKT cells bridge innate and acquired immune responses.
    • Abnormal NKT cell function may be associated with cancer and autoimmune disease.
  28. What are the features of B lymphocytes?
    • These lymphocytes are unique due to their ability to secrete immunoglobulins (Defined by the presence of immunoglobulins)
    • B cells are produced in the bone marrow.
    • The development of B cells occur at various stages
    • Express both IgM and IgD molecules
    • Expression of IgG, IgA and IgE on the cell surface is not common in circulation
    • Majority of B cells carry MHC class II antigens
  29. What are the features of Natural Killer cells?
    • NK cells are the third largest class of lymphocytes.
    • They develop in bone marrow from common lymphoid progenitor.
    • NK cells share effector function and the ability to produce cytokines with T cells. They do not express either T cell or B cell receptors.
    • Large granular lymphocytes.
    • NK cells participate in innate immunity and are the first responders against infection and possibly tumors.
    • They carry CD56 antigen
    • The killing ability of NK cells is associated with the expression of MHC Class I molecules.
  30. What are the Antigen Presenting cells?
    • Macrophages
    • B cells
    • Dendritic cells
    • Langerhan cells
    • Interdigitating cells
  31. What are the features of Macrophages?
    • Macrophages participate in innate as well as acquired immune response.
    • They are phagocytes which continuously remove self proteins which are degraded and presented to T cells
    • The most important role of macrophages is antigen presentation.
    • They also play a role in inflammatory responses, anti-tumor activity, microbicidal activity, lymphocyte activation and tissue reorganization.
    • Most of their effects are mediated via cytokines.
    • They release oxygen dependent free radicals, collagenases, and angiogenesis factors.
  32. What are the features of Dendritic Cells?
    • Dendritic cells are antigen presenting cells.
    • They are distributed in small quantities in various tissues including skins, inner lining of the nose, lungs, stomach and intestine.
    • The blood contains immature dendritic cells.
    • After activation, dendritic cells migrate to the lymphoid tissue to initiate an acquired response after interacting with B and T cells.
    • There are two most common types of dendritic cells, myeloid dendritic cells and lymphoid dendritic cells.
  33. What are the features of Myeloid dendritic cells?
    • Secrete IL-12 and are very similar to monocytes
    • mDC can be divided into at least two subsets, mDC1 and mDC2.
    • mDC1 stimulates T cells, whereas mDC2 may have a role in fighting wound infection.
  34. What are the features of Lymphoid dendritic cells?
    • Similar to plasma cells and produce high levels of interferon-ϒ.
    • The dendritic cells are of hematopoietic origin.
    • The myeloid dendritic cells are of myeloid origin and lymphoid dendritic cells are of lymphoid origin.
  35. What are the features of Neutrophils/Polymorphonuclear leukocytes?
    • They are produced in the bone marrow.
    • Neutrophils are phagocytes.
    • They utilize a number of bactericidal substances, lytic enzymes, and both oxygen-dependent and oxygen-independent pathways to kill microbes.
  36. What are the features of Eosinophils/Polymorphonuclear leukocytes?
    • Eosinophils develop in bone marrow, where they also mature.
    • Eosinophils are also capable of phagocytosis.
    • They are involved in combating parasitic infection and play a role in allergic disease.
  37. What are the features of Basophils and Mast cells?
    • Basophils are of bone marrow origin.
    • They secrete a number of mediators including histamine, leukotrienes, and several cytokines.
    • Mast cells are similar to basophils, but they have different precursor cells in the bone marrow. The precursor cells for both basophils and mast cells express CD34.
Author
kyleannkelsey
ID
284920
Card Set
Immuno - Lecture 1 - 2
Description
Immuno - Lecture 1
Updated