Immunology Chapter 1

Immunology = resistance to infectious disease

Ancient Greek = Thucydides wrote immunity to “plague”

Ancient Chinese = inhale powder of skin lesion crust from people who had smallpox (variolation)

Edward Jenner = developed first vaccine

• milkmaids never got smallpox, but got cowpox

• he injected cowpox into little boy

• then injected smallpox

• little boy never developed smallpox

Professional Phagocytes

• phagocytes, PMN, monocyte, and macrophages

1.) Phagocytes = ingest and destroy foreign substances

2.) PMN (multi-lobed irregular shaped nucleus):

• AKA granulocyte (contains granules in cytoplasm)

  • basophil: circulate blood, protects against parasitic infections, allergy response, and makes substances that control vascular permeability

  • eosinophil: circulate blood, includes inflammation, activated by specific immune response, parasitic infection, and allergy response

  • neutrophil: circulation blood, professional phagocyte, important in innate immunity, and contains numerous phagocytes

3.) Monocyte (peripheral blood mononuclear cell)

• location = blood

• single lobed, kidney bean shaped nucleus

4.) Macrophage

• location = tissue

• engulf and digest foreign substances

• antigen presenting

Resident Macrophage

• CNS = microglial cells

• liver = Kupferr cells

• lungs = alveolar macrophages

• bone = osteoclasts

• kidney = intraglomerular mesangium

Mast Cells

• location = tissue

• same function as basophils

• allergy/hypersensitivity reaction

ILC

• location = dermis, liver, lungs, small intestine, and lymphatic tissue

• produces cytokines

Natural Killer Cells (NK Cells)

• destroys infected cells in body

Dendritic Cells

1.) Interdigitating dendritic cells

• skin = Langerhans cells

• antigen presentation of T cells

2.) Follicular dendritic cells

• lymph nodes

• antigen presentation of B cells

B lymphocytes (B cells)

• turns into plasma cells when activated

• secrete antibodies

T lymphocytes (T cells)

• cytotoxic T cells = kills infected cell

• helper T cells = control immune response and activation

• regulatory T cells = suppression of immune response

Innate Immunity (not specific)

• skin = protective layer preventing infection

• mucosal epithelial cells = mucus traps foreign substances, cilia from upper respiratory tract pushes them in and out

• antibacterial chemicals = paneth cells produce antimicrobial chemicals (lysosomes and stomach acid)

Specific Immunity

1.) Humoral Immunity

• production of antibodies and antibodies produced by B lymphocytes

2.) Cell Mediated Immunity

• specific T cells become activated

Development of Immune System Cells

• bone marrow is where all blood originates

• production of all blood cells = hematopoiesis

• fetus = blood begins in blood islands → liver → spleen

• puberty = bone marrow in flat bones

Pluripotent Stem Cells

• AKA self-renewing cells

• regenerates itself

• protein CD34

1.) Common lymphoid progenitor (all circulate bloodstream and lymphatic tissue)

• B cells = differentiate into plasma cells that secrete antibodies when activated

• T cells = become T effector cells when activated

• NK cells = becomes activated to kill infected cells

• ILC = produce cytokines

2.) Common myeloid progenitor

• dendritic cells = circulate blood, tissues, and lymphatic system → follicular dendritic cells

• megakaryocyte/erythroid = megakaryocyte (break into platelets), erythroblasts (develop into RBC)

• granulocyte/macrophage = forms PMNs (gives rise to mast cells) and forms monocytes (gives rise to macrophages)

Colony Stimulating Factors

• differentiate from pluripotent stem cells from cytokines

• controls how much each blood cell type is produced

• produced by stromal cells and macrophages in bone marrow

• produced by activated T cells during or after infection