Chapter 1

  1. 3 Big Killers
    • Tuberculosis
    • HIV
    • Malaria
  2. Strategies of Pathogen Recognition
    • Innate - detect molecular patterns common to groups of pathogens
    • Different microbes = same receptors
    • Adaptive - detect unique determinates of each pathogen
    • Different microbes = different antibodies
  3. Virulence Theory
    • Ability of a pathogen to cause disease
    • Pathogen carry out replication and transmission > if its kills host before transmitted, it dies out > more hosts = more virulent > over time there's fewer hosts = less virulent
  4. New Disease
    • Ebola
    • SARs
    • Influenza
  5. Prions
    • Proteinaceous Infectious Particle
    • Made only of protein
    • Abnormally-structure forms of a host protein, which convert normal molecules of the protein into the abnormal structure
    • Ex. Mad cow disease
  6. Classes of Pathogens
    • Virus - intracellular (HIV)
    • Fungus - extraceluluar (Thrush-Candida albicans)
    • Bacteria - intra and extra (Listeria)
    • Parasite - intra and extra (Helminth worm)
  7. Tasks of Immune System
    • Differentiation of self versus non-self
    • Pathogen versus host
    • infected versus healthy
  8. Innate Immunity
    • All animals have an an innate immune system
    • Basis is receptor recognition of molecular patterns in microbes, but not animals)
    • Receptors limited in specificity and recognize classes of pathogens
    • Receptors encoded in germline - idential receptors on all cells of a lineage
    • Immediate response
  9. Innate Immunity Response
    • Recognize a foreign presence
    • Destroy (eat/chemical)
    • Alarm
  10. Flaws of Innate Immunity
    • Parasitic agents have a generation time orders of magnitude less than that of their hosts
    • Only limited amplification of the response
    • No memory
  11. Adaptive Immunity
    • Adds to innate immune response
    • HIghly specific response to unique components of the pathogen
    • Provides long-lasting protection (immunological memory)
  12. Adaptive Immunity Response
    • Recognize a foreign presence
    • Destroy infected cells
    • Neutralize/antibodies
    • Activate/direct other cells to destry pathogens
    • Form memory
  13. B cells
    Antibody factories
  14. T Cells
    Direct elimination of infected cells and direction of innate and lymphocyte responses
  15. Flaws of Adaptive Immunity
    • Slow - requires 3-5 days to become effective
    • Can be tricked and evaded by pathogens
  16. Graph of Innate and Adaptive
    Image Upload 1
  17. Where is the innate system?
    • Tissue
    • Blood
    • Bone marrow
  18. Where is the adaptive system?
    • Lymphoid organs
    • Blood
    • Tissue
    • Bm
  19. Lymph node-like tissues
    • GALT - gut associated lymphoid tissue
    • BALT - bronchial
    • MALT - mucosal
  20. Preventing Infection
    • Skin is body's first defense
    • Mechanical - epithelium, flow of fluid, mucus
    • Chemical - sebum, enzymes, lysozyme, acidity
    • Microbiological - normal flora
  21. Mucosal Surfaces
    • Fluid layer that contains glycoproteins, proteoglycans, and enzymes
    • Respiratory: mucus continuously removed through epithelial cells with cilia and secrete mucus by goblet cells
  22. Defensins
    • Kill bacteria, fungi, and enveloped viruses
    • Perturb their membranes
  23. Inflammation
    • Cells and proteins in damaged tissue sense presence of bacteria and cells send out soluble protiens -> cytokines
    • Cytokines react with other cells to trigger innate immune -> overall effect is inflammation
    • Inflammation is immune system's response to the infection
  24. Cytokines
    • Induce vasodilation -> increase blood flow (skin rred and warm)
    • Permeable endothelium
    • Leakage of blood plasma into tissue -> edema
    • Change adhesive properties of vascular endothelium -> WBCs attach -> move from blood into tissue
  25. Clonal Selection
    • During infection, only those lymphocytes bearing receptors that recognize the infecting pathogen are selected to participate in adaptive response
    • These then proliferate and differentiate to produce lartge number of effector cells specific to that pathogen
  26. Leukocytes
    White blood cells
  27. Hematopoiesis
    • Generation of the cellular elements of blood
    • WBC, RBC, and platelets
    • Occurs in bone marrow - skull, ribs, sternum, vertebral column, pelvis, femurs
  28. Hematopoietic Stem Cells
    • Any blood cell or its precursor cell types
    • Divide to make more of its own - self-renewal OR
    • Become mature stem cells > erythroid, myeloid, lymphoid
    • Erythroid - platelets and erythrocytes
    • Myeloid - granulocytes, monocytes, macrophages, dendritic, mast cell
    • Lymphoid - NK, B-cells, T cells
  29. Platelets
    • Non-nucleated
    • Maintain integrity of blood vessels
    • Intiate and participate in blood clotting reactions
  30. Megakaryocytes
    • Nuclie containing multiple sets of chromosomes
    • Permanent residents of bone marrow
    • Produce platelets
  31. Granulocytes
    • Have prominent cytoplasmic granules containing reactive substances that kill microorganism and enhance inflammation
    • Irregular shpaed nuclei - 2 to 5 lobes
    • Most abundant - neutrophil
    • Also have eosinophil and basophil
  32. Neutrophil
    • Specialized in the capture, engulfment, and killing of microorganisms
    • Phagocytic
    • Effector cells or innate immunity that rapidly mobilize to enter sites of infection
    • Short lived and die at site of infection
  33. Monocytes
    • Leukocytes that circulate in the blood
    • Mobile progenitors of macrophages
    • Travel in blood to tissues > mature into macrophages > take up residence
  34. Macrophage
    • Phagocytic
    • Extensive cytoplasm with many vacuoles
    • Scavenger cells of the body
    • Long-lived
    • First phagocytic cell to sense invading microorganism
    • Secrete cytokines
  35. Dendritic Cells
    • Residnt in the body's tissues
    • Act as cellular messengers that are sent to call an adaptive immune response
  36. Mast Cell
    • Resident in all connective tissues
    • Contribute to inflammation
  37. Natural Killer Cells (NK cells)
    • Large granular lymphocytes
    • Effector cells of innate immunity
    • Enter infected tissue and prevent spread of infection > killing them and secreting cytokines
  38. Small Lymphocytes
    • Responsible for adaptive immune response
    • Circulate in an immature form that is functionally inactive
    • Recognition of a pathogen drives a process of lymphocyte selection, growth, and differentiation
  39. B lymphocytes (B cells)
    Cell surface receptors for pathogens are immunoglobulins
  40. T lymphocytes (T cells)
    • T-cell receptors
    • Cytoxic T cells and helper T cells
  41. Cytoxic T cells
    Kills cells that are infected with viruses or bacteria
  42. Helper T cells
    Secrete cytokines
  43. Primary Lymph Tissue
    • Thymus - T cells
    • Bone Marrow - B cells
    • Lymphocytes develop and mature to the stage at which they are able to respond to pathogen
  44. Seondary Lymphoid Tissues
    • Spleen, lymph nodes, tonsils, appendix
    • Sites where mature lymphocytes become stimulated to respond to invading pathogens
    • Also includes associated lymphoid - GALT, MALT, BALT
  45. What organ deals with pathogens that make it to the blood?
    • Spleen - filter for the blood
    • Remove damaged red cells
    • Defend body against blod-borne pathogens
    • Pathogens and lymphocytes enter and leave the spleen in the blood
Card Set
Chapter 1