BB LEC 1

• Locations of lymphoid tissue

  • Lymph nodes
  • Spleen
  • Diffuse lymphoid tissue found in the mucosa of the digestive system, including the tonsils, peyer patches, and appendix
  • MALT (digestive, respiratory, or urogenital mucosae)
• Two main types of immunity

  • Innate/Native/Natural/Non-specific Immunity
  • Adaptive/Acquired/Specific Immunity
• Natural immunity is present at birth
• Adaptive immunity is not present at birth
• Upon exposure to antigen of chickenpox


  Body makes antibody against the antigen of chickenpox
• Next exposure to chickenpox

  Not affected due to the antibody made; increased response with more antibodies made for the antigen
• Reactivation stage (MycoViro) - relapse of chickenpox called "varicella zoster virus" (not important)
• Natural Immunity vs. Adaptive Immunity

  • Specificity: Non-specific vs. Specific
  • Diversity: Standardized response to antigen vs. Diversed response
  • Memory: None vs. With memory
• Humoral factors


  • Complement proteins (C1 - C9)
  • INF (Interferons)
  • Properdin
  • Beta lysins
  • TNF (Tumor Necrosis Factor)
  • Inflammation
  • Fever
• Activated T cells

  1. Produces cytokines

  2. Produces lymphokines
• Activated B cells

  Produces antibodies or immunoglobulins
• Cells involved in immunity

  • Monocytes (Plasma/ in bloodstream)
  • Macrophages (from blood migrated to tissues)
  • Granulocytes (Baso, Eosino, Neutrophils)
  • Natural Killer (NK cells)
• Antigen presenting cells (APCs)

  • Macrophage
  • Monocytes
  • Dendritic cells
• Phagocytes are considered APCs
• Key features in pathogen recognition

  • Toll-like receptors recognize PAMPs
  • Memory B cells remember exposure
• First line of defense

  • Physical Component
  • Biochemical Component
  • Cellular Component
• Second line of defense

  • Physical Component
  • Biochemical Component
  • Cellular Component
• Third line of defense

  • Physical Component
  • Biochemical Component
  • Cellular Component
• Saliva components

  • Lysozymes
  • Digestive enzymes
• Acidic components of the body

  • Vagina - Acidic pH
  • Stomach - Hydrochloric acid and pepsin
• Inflammation


  1. Initial reaction when foreign or harmful substance try to invade the body

  2. Cardinal signs of inflammation: Redness, Swelling, Heat, Pain, Loss of function
• Fever
• Plasma - anticoagulated portion of blood
• Serum - coagulated portion of blood
• Natural Immunity
• Vascular response

  Increased vascular permeability is the hallmark of acute inflammation
• Cellular response

  Neutrophils - first to migrate; Monocytes - second to migrate; Margination, Rolling, Adhesion, Diapedesis, Chemotaxis, Opsonization, Phagocytosis
• Resolution and repair


  Final stage of inflammation associated with increased proliferation of fibroblasts
• Opsonization


  Coating of the bacteria so that they are easily phagocytosed
• Phagocytosis


  Process by which bacteria are killed/eaten up by the white blood cells
• Resolution and Repair


  Final stage of inflammation associated with increased proliferation of fibroblasts, which may result in: The affected area being repaired totally, The affected area leading to the formation of abscess with loss of function, Granuloma formation
• Phagocytosis (discovered by Elie Metchnikoff)


  ICED: Initiation, Chemotaxis, Engulfment, Digestion
• Phagocytosis Initiation

  Activated phagocyte has increased surface receptor for the adherence of Complement receptor 3, Laminin receptor, FLMP (Formyl, Leucyl, Methionyl, Phenylalanine)
• Chemotaxis


  Unidirectional or targeted movement of the leukocytes towards antigen/bacteria in response to certain chemicals. Without chemotaxis, cells motion is random. Examples of chemotaxins: Complement 3a (C3a), Complement 5a (C5a), Interleukin 8
• Job’s Syndrome is a disease with impaired chemotaxis
• Lazy Leukocyte Syndrome/Hyperimmunoglobulin E is a disease with impaired random movement and chemotaxis
• Engulfment

  Fusion of phagosome and lysosome to form phagolysosome
• Digestion

  Oxygen-dependent killing, kill bacteria using toxic oxygen derivatives via respiratory burst. Enzymes involved are NADPH oxidase, catalase, superoxide dismutase (SOD). Disorder associated with impaired NADPH oxidase is called CGD (Chronic Granulomatous Disease)
• Test used for CGD: nitroblue tetrazolium test (+) the dye did not oxidize
• Latest assay used for CGD: FLOW CYTOMETRY (Neutrophil Oxidative Index Test)