ap bio immune system

Immune System

Immune response in plants

• Barrier defenses

  • Waxy cuticle

  • Thorns and spines

  • Hairs

• Physical adaptations

  • Leaf shedding

  • Leaf coloration

  • Thigmonastic movements

  • Lenticles

• Defense against Herbivory

  • Secondary metabolites

    • Chemicals used in defense, not needed for plant survival

      • Act on nervous system of herbivores

      • Mimic natural hormones

      • Damage digestive tracts of herbivores

      • Fungicides

• Hypersensitive Response

  • Localized death of plant cells

  • Isolate infected area

• Systematic Acquired Resistance

  • Salicylic acid

  • Induce the production of pathogen-related proteins

  • Protect plant for several days

Innate Immunity

• 1st line of defense - physical barriers

  • Skin 

  • Mucus membranes

• Body passages with innate immunity

  • Trachea lined with mucus-secreting cells and ciliated cells

  • Low pH of stomach acid

  • Low pH of urinary tract

  • Lysozymes in tear ducts

  • Low pH of reproductive tract

• 2nd line of defense - leukocytes

  • Phagocytes - engulfs particles

  • Lymphocytes - T-cells

  • Natural killer cells

  • Basophils & Mast cells - produce histamines to induce inflammation

• TLR Receptors

  • Receptors that recognize signature molecules of pathogens (PAMPs)

  • Signal transduction is activated when PAMP binds to receptor

• Chemical response

  • Chemokines

  • Signals leukocytes to infection site (positive chemotaxis)

• Interferons

  • Proteins made by virus infected cells to alert neighboring cells

  • Neighboring cells activate an antiviral state once interferons are recognized

Adaptive Immunity

• Lymphocytes

  • Naive lymphocytes - fully developed inactive WBCs

  • Plasma B - Produce antibodies

    • Produced in bone marrow

  • Memory B - reserve B cells

    • Activated if pathogen returns

  • T cells - mature in thymus

    • Helper T - activate B cells in humoral response

    • Cytotoxic T destroy infected cells with toxins

    • Memory T - activated if pathogen returns

• MHC Proteins

  • MHC I

    • On All cells

    • Unique to individuals

  • MHC II

    • On antigen presenting cells (macrophages)

  • MHC genes have multiple alleles (polymorphic)

    • Reason for transplant rejections

• Cell Mediated Immunity

  • T cell recognition & destruction of infected cells

  • Review PPt 3 slides 25-33

• Humoral Immunity

  • B cells produce antibodies

  • Review PPt 4 slides 5-7

• Role of Helper T Cell

  • Match with MHC II of APC 

  • Secretes interleukin-II to activate specific plasma B cell and Cytotoxic T Cell

• Autoimmune Disorder

  • Identify and explain one Autoimmune disorder

    • Graves Disease

      • Antibodies attach to thyroid receptors

      • Overproduction of thyroxine

    • Type 1 Diabetes 

      • B cell antibodies attack proteins found on islet cells of the pancreas which destroy the cells responsible for making insulin. 

• Blood typing

*Type O is a universal donor because O blood does not have antigens present to recognize or fight against

• HIV

  • Retrovirus

  • Only infects cells with CD4 protein

    • Helper T Cell

    • Dendritic Cell

    • Macrophage