Antibodies

Question 1

Follicular Dendritic Cell

Answer 1

specialized dendritic cells found in the germinal center of spleen, lymph nodes, and Peyer’s patches. Essential for antibody production and the development of B cell memory

Question 2

Do Follicular dendritic cells have MHC Class II?

Answer 2

no, they have immunoglobulin receptor and complement receptor

Question 3

Follicular DC response in animals previously exposed to antigen

Answer 3

1. the antigen and antibody combine to form complexes
2. Follicular DCs take up these immune-complexes on their surface and present them to B cells
3. B cells take up and process the antigen, present it to antigen-sensitive T cells

Question 4

Follicular DC response in animal that has not been previously exposed to antigen

Answer 4

1. Antigen presentation is a passive process.

2. FDC provides a surface on which antigen can be presented to B cells

Question 5

Antibodies

Answer 5

proteins found in blood seruum

Question 6

What are the main antibodies found on serum electrophoresis

Answer 6

gamma globulins, aka immunoglobulins

Question 7

Classes of Immunoglobulin

Answer 7

IgG, IgA, IgM, IgE, and IgD

Question 8

Immunoglobulins

Answer 8

family of glycoproteins produced in membrane-bound or secreted form by B lymphocytes. Function as mediators of specific humoral immunity by neutralizing microbes and toxins and by engaging various effector mechanism that serve to eliminate the bound antigens.

Question 9

Components of Immunoglobulins

Answer 9

Symmetric core structure of 2 identical covalently linked heavy chains and two identical light chains, each one linked to one of the heavy chains. There are intrachain disulfide bonds

Question 10

How are antibodies classified?

Answer 10

into different isotypes and subtypes on the basis of differences in the heavy chain C regions. Both the light chains of a single Ig molecule are of the same isotype, either kappa or delta, which differ in their single C domains

Question 11

Proteolytic digestion of antibodies

Answer 11

yields three fragments: 2 Fabs and one Fc

Question 12

Immunoglobulin G

Answer 12

predominant immunoglobulin in blood serum. Mainly produced by plasma cells in secondary immune responses. Small enough to enter inflamed tissues or cross the placenta in primates.

Question 13

Immunoglobulin M

Answer 13

five subunits and a joining chain. Second highest concentration in blood. Predominates the primary immune responses. More effective than IgG when based on molar activity. Too large to enter inflammatory sites or cross the placenta in primates.

Question 14

Immunoglobulin A

Answer 14

mainly produced on mucosal surfaces. Responsible for protection of those surfaces. Usually dimeric. Protected from digestion by secretory component.

Question 15

Immunoglobulin E

Answer 15

present in extremely small amounts in blood. Responsible for immunity to parasitic worms and allergies. Also for some mucosal protection

Question 16

IgE role in allergies

Answer 16

They bind to high-affinity receptors on the surface of mast cells and basophils and the subsequent cross-linking of these molecules with the allergen releasing histamines and other mediators, causing bronchoconstriction, lunch and airway hyperresponsiveness observed in asthma

Question 17

Immunoglobulin D

Answer 17

structure highly variable between mammals. Found on the surface of B cells. May be involved in defense against the microbiota. Function unclear

Question 18

Affinity Maturation

Answer 18

somatic mutations in variable region. Increases affinity for antigen

Question 19

Change from membrane to secreted form

Answer 19

change from B cell receptor function to effector function

Question 20

Isotype Switching

Answer 20

each isotype serves a different set of effector functions

Question 21

Affinity

Answer 21

the strength of the binding between a single combining site of an antibody and an epitope of an antigen

Question 22

Avidity

Answer 22

the overall strength of attachment. Is much greater than the affinity of any one-antigen binding site. A low-affinity IgM molecule can still bind tightly to polyvalent antigen because many low-affinity interactions can produce a high-avidity interaction.

Question 23

Monovalent

Answer 23

single arm of immunoglobin. Low avidity

Question 24

Bivalent

Answer 24

Bind to two antigens. High avidity

Question 25

Polyvalent

Answer 25

bind to many antigens. Very high avidity

Question 26

Bovine Immunoglobulins

Answer 26

have a very long variable domain. Folds into a ball and stalk structure. The tightly folded ball structure is highly variable and binds antigen

Question 27

Immunologic Events that cause the peripheral eosinophilia as well as large number of cells in the respiratory secretions

Answer 27

1. First exposure to pollen
2. IL-4 drives B cells to produce IgE in response to pollen antigens
3. Pollen-specific IgE binds to mast cell
4. Second exposure to pollen
5. Acute release of mast-cell contents causes allergic asthma