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19 Cards in this Set
- Front
- Back
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sensitization
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primary exposure to antigen
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immediate phase
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5-60 minutes
controlled by histamine and other mediators stored in granules of mast cells |
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late phase
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4-24 hours
controlled by eosinophils |
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Sensitization phase
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uptake of soluble Ag by APC
Ig-class switching of IgE est. of IgE+ memory B cells and memory T cells |
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immediate phase
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upon 2nd exposure
crosslinking of 2 or more IgE leads to degranulation of mast cells |
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Late phase
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involves Th2 cells
release IL-4, IL-13 Release IL-5, which stimulates eosinophils (from bone marrow to tissues) |
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immunological hypersensitivities
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lead to tissue damage
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anaphylaxis
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used to describe systemic immediate hypersensitivity
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Type I hypersensitivity
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aka immediate hypersensitivity
IgE degranulation of mast cells, basophils, eosinophils rxn occurs very fast often assoc. w/ autoimmune diseases Asthma, hayfever, anaphylaxis, food allergy |
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Type II hypersensitivity
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Cytotoxic hypersensitivity
involves IgG and complement causes inflammation in tissues, circulating Abs react w/ host cell surface assoc. with Goodpasture syndrome, Purpura/drug sensitivity, hemolytic disease of newborn (Rh-antigen of RBC), and Myasthenia Gravis |
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Type III hypersensitivity
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Immune complex hypersensitivity
involves circulating Ab-Ag complexes complexes fix complement to release anaphylatoxin C3a and C5a tissue deposition leads to tissue damage release of vasoactive amines from basophils and other inflammatory cells (neutrophils) assoc. w/ Serum sickness, Arthus rxn, systemic lupus erythematosus, and extrinsic allergic alveolitis |
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Type IV hypersensitivity
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Delayed hypersensitivity
assoc. w immune cells, not Abs mycobacteria, TB injection cytokines induce more TNF alpha, IL-1 and IL-6, which induces productions of chemokines chemokines attract macrophages and other T cells to lesions assoc. with delayed hypersens, contact hypersens, and TH2 responses |
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Type V hypersensitivity
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changes physiology
assoc. w/ Graves disease and Myasthenia gravis (can be Type V or Type II) |
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CD19
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coreceptor of BCR
specific marker of BCR |
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CD 19 and CD21
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B cell co-receptors needed for potent response/activation of B cells
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CD 21
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binds complement recptor C3b
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B cell needs CD 19 and CD21
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also needs CD4 T helper cells in order to create potent response
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T helper cell role in B cell activation
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Ag binds BCR=1st signal to B cell
Helper Th2 cell=delivers 2nd signal to B cell via CD40L and cytokines B cell proliferates and differentiates into plasma cells |
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B cells develop in bone marrow
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mature B cells migrate to lymph nodes via bloodstream
leave via efferent lymphatic vessel |
