antibody function

IgG: 1. ________ monomer; MW ~150 kd 2. How common is his Ig? 3. How many subtypes and what are they called? 4. Which is the abundant? Least? 5. Homology is 90-95% with greatest differences in ___ region. 6. What are the molecular forms in serum?

1. H2L2 2. this is the most prevalent Ig in peripheral blood 3. 4 subtypes: IgG1 (66% of total IgG), IgG2 (23%), IgG3 (8%), IgG4 (3%) 4. IgG1= most abundant; IgG4- least abundant 5. H 6. γ12Κ2, γ12λ2, γ22Κ2, γ22λ2, γ32Κ2, γ32λ2, γ42Κ2, γ42λ2

The ability of antibodies to mediate effector responses is dependent not only on their ________ ___________, but also on their _________(heavy-chain class or subclass).

antigen specificity; isotype

Antibody-Mediated Effector Functions include... (6)

neutralization, agglutination, opsonization, complement activation, Ab dependent cell mediated cytotoxicity (ADCC), and degranulation

What are the 2 kinds of IgA?

serum IgA and secretory IgA

Antibody-Mediated Effector Functions: Describe the function of the following: 1. neutralization 2. agglutination 3. opsonization 4. complement activation 5. ab dependent cell mediated cytotoxicity (ADCC) 6. degranulation

1. To neutralize (inactivate) pathogens or toxins 2. Antibodies agglutinate pathogens facilitating their clearance 3. opsonizing pathogens or altered cells by binding and recruiting phagocytic cells 4. Binding to pathogen and initiating the complement cascade 5. Binding and recruiting the activities of cytotoxic cells, most often natural killer (NK) cells 6. Anti-pathogen antibodies can trigger mediator release from granulocytes through a process called degranulation.

IgD Effector Function: 1. Ig D was recently found to bind to ___________ and ________ cells 2. These cells are activated after __________ binds to IgD 3. Binding causes them to release 3 things... 4. On the membrane of __ cells, IgD is co-expressed with Ig__, signaling the differentiation of an immature into a mature __ cell 5. Membrane Ig__ and membrane Ig__ function as antigen receptor for __ cells

1. basophils and mast cells 2. antigen 3. antimicrobial peptides, cytokines and chemokines 4. B; IgM; B 5. IgM; IgD; B

Effector function of Secretory IgA: 1. Mucosal immunity is mediated by secretory IgA in what 4 secretions? 2. IgA can __________toxins and pathogens and enhance their clearance 3. Because IgA cannot fix complement, these interactions do not induce _____________ 4. IgA antibodies are highly _____________, enabling them—with bound pathogens—to associate with the mucus layer, facilitating their _____________. 5. The multimeric IgA antibodies are particularly effective in ______________pathogens, enhancing their clearance from the body

1. breast milk, saliva, tears, and mucus. 2. neutralize 3. inflammation 4. glycosylated; clearance 5. agglutinating

IgG Effector Functions: 1. Activation of the _________ ____________. IgG__ activates this system more efficiently that IgG__. 2. ____________ by IgG for enhanced phagocytosis. IgG__ is the same as IgG__, and both are more efficient than IgG__ 3. __________ immunity mediated by maternal IgG. IgG__ is the same as IgG__ and IgG__. 4. Antibody-dependent cell-mediated __________ 5. Excellent antibody for ____________ of toxins 6. Efficient at ______________ various motile bacteria 7. Efficient as a _____ neutralizing antibody 8. Major isotype produced in ___________ humoral response

1. complement system; IgG3>IgG1 2. opsonization; IgG1=IgG3>IgG4 3. Neonatal; IgG1= IgG3=IgG4 4. cytotoxicity 5. neutralization 6. immobilizing 7. virus 8. secondary

IgE Effector Functions: 1. Immediate-type _______________ (asthma, anaphylaxis, hives, etc.) is triggered by IgE. 2. IgE is bound to the Fc receptors on membrane of blood ___________ & tissue _____ cells. 3. ________-_________ of IgE by antigen (called allergen) induces basophils and mast cells to _______________. 4. Name 3 pharmacologically active mediators released that give rise to allergic manifestations.

1. hypersensitivity 2. basophils; mast cells 3. cross-linking; degranulate 4. histamine, serotonin, basic peptide, etc.

IgD: 1. H2L2 ____________. MW 150 kd. 2. [Serum] is variable but generally ___, constituting ~0.2% of total Ig in serum. Because of its susceptibility to proteolysis by serum _______, IgD is difficult to isolate.

1. monomer 2. low; plasmin

IgE: 1. H2L2 __________. MW 190 kd. 2. Typical concentration in serum? 3. Found membrane bound to ________ and ______ cells

1. monomer 2. very low! Normally IgE occurs in serum at the lowest concentration, 0.002% of total serum Ig. 3. basophils and mast cells

Serum IgA: 1. 80% is H2L2 _______ (MW ~150 kd) and 20% is in _______, ________, __________, and _________ forms held together by one additional J chain (identical to J chain of IgM). Constitutes 10-15% of total serum Ig. 2. Two subisotypes _____ and _____ with homology ›90% 3. IgA__ is more prevalent in the serum 4. Serum IgA has no known, unique _______ mechanism 5. both subclasses can stimulate ___________, mediate ADCC by binding FcRs on ____ cells, and trigger _____________of granulocytes.

1. monomer; dimer, trimer, tetramer, and pentamer 2. IgA1 and IgA2 3. IgA1 4. defense 5. phagocytosis; NK cells; degranulation

Secretory IgA: 1. Most consist of 2 IgA __________ (dimer), 1 __ chain, and 1 __________ ____________ piece (~70 kd). Some exist in the form of __________. MW 370 kd (tetramer 670 kd). 2. Function of the SC piece is to wrap around the ____ region of Ig__ and Ig__ molecules to cover sites susceptible to cleavage by proteolytic enzymes and thus protect the Igs from the proteases that are abundant in the mucosal environment 3. The major antibody class present in _________. (IgA__ is more prevalent in secretions).

1. monomers; J chain; secretory component (SC); tetramers 2. Fc; IgA and IgM 3. secretions; IgA2

IgM: 1. ______________ H2L2 (monomer MW ~180 kd) with one additional__________ chain. MW ~900 kd. Constitutes 5-10% of total serum Ig. 2. Molecular forms in serum: __________, __________ 3. Molecular form when membrane bound: ______, __________

1. pentameric; joining (J) 2. •(μ2Κ2)5, (μ2λ2)5 3. μ2Κ2, μ2λ2

IgM Effector Functions: 1. IgM is the 1st Ig isotype synthesized in the ______ humoral immune response 2. IgM is the 1st isotype synthesized by __________ 3. Activation of the _______ ___________ in serum (more efficient than Ig__) 4. Neutralization of ________ in the serum 5. __________ IgM is membrane bound & functions as the antigen receptor on the surface of __ cells

1. primary 2. neonates 3. complement system; IgG 4. virions 5. monomeric; B

Clonal Selection Theory of Antibody Formation: 1. B cells develop from ________ cells in the ______ __________ of adults (__________ of fetuses). 2. After maturation, B cells migrate to __________ organs such as... (2) 3. ________ ___________: When a B cell encounters an antigen it recognizes, it is stimulated and differentiates into a ___________ cell, which actively secretes antibody. 4. Each B cell produces an antibody whose _________ specifically recognizes (binds) only one _________

1. stem; bone marrow; liver 2. lymphoid; lymph node or spleen 3. clonal selection; plasma 4. paratope; epitope