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