Not antigen specific Rapid defense mechanisms exist before antigen exposure No

Not antigen specific rapid defense mechanisms exist

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Not antigen specificRapid- defense mechanisms exist before antigen exposureNo memory- no enhanced response on second antigen exposuresPromotes initiation of adaptive responsesAdaptive immunity - Role of B cells, T cells, Th cells B Cells: develop in the bone marrowCell surface marker:CD19 or CD20
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Have specific antigen receptor called the B cell receptor (BCR)The primary function of the B cell is to make antibodyA fully differentiated B cell is called a Plasma CellT Cells: develop in the thymusCell surface marker:CD3+Have a specific receptor- the T cell receptor (TCR) used to identify antigenT Cell subsetsCytotoxic T cells (CTL) → kill tumor cells and virus infected cells. CD8+Helper T cells (Th)→ help other cells by making important proteins (cytokines) CD4+CD4+, if below 200 then you have AIDSTypes of hypersensitivity Hypersensitivity - umbrella term → allergy, autoimmunity, alloimmunity; diseases caused by an exaggerated immune response’ could be response against a pathogen, non-pathogen or self may be directed by antibodies, lymphocytes orinnate pathways; 4 types of hypersensitivity reactions:
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Type I: most commonImmune reactant: IgEAntigen: soluble antigenEffector mechanism: mast-cell activationExample of hypersensitivity reaction: Allergic rhinitis, allergic asthma, atopic eczema, systemic anaphylaxis, some drug allergies IgE- mediated allergic reactionsSystemic anaphylaxisCommon allergens: drugs, venoms, food (eg. peanuts), serumRoute of entry: intravenous Directly or following oral absorption into the blood after oral intake Response: edema, increased vascular permeability, laryngeal edema, circulatory collapse, DEATHAcute urticaria (wheal-and-flare)Common allergens: animal hair, insect bites, allergy testingRoute of entry: through skin, systemicResponse: local increase in blood flow and vascular permeability, edemaSeasonal rhinoconjunctivitis(hay fever)Common allergens: pollens (ragweed, trees, grasses), dust-mite fecesRoute of entry: contact with conjunctiva of eye and nasal mucosa Response: edema of conjunctiva and nasal mucosa, sneezingAsthmaCommon allergens: danders (cat), pollens, dust-mite fecesRoute of entry: inhalation leading to contact with mucosal lining of lower airwaysResponse: bronchial constriction, increased mucus production, airway inflammationFood allergyCommon allergens: peanuts, tree nuts, shellfish, fish, milk, eggs, soy, wheatRoute of entry: oralResponse: vomiting, diarrhea, pruitis (itching), urticaria (hives), anaphylaxis Type II: allergen needs to first be on tissue, occur when antibodies react to altered components of self Immune reactant: IgGNOT soluble antigen *Antigen: cell- or matrix- associated antigenEffector mechanism: complement FcR+ cells (phagocytes, NK cells)Example of hypersensitivity reaction: some drug allergies (ex: penicillin)Antigen: cell-surface receptor
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