Immunoglobulin Structure Lecture 4 Flashcards Preview

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Flashcards in Immunoglobulin Structure Lecture 4 Deck (23):
1

How do Ig classes differ?

constant region in the heavy chain

2

What is the structure of IgM?

pentameric IgM

3

What is the secretory structure of IgA?

Dimeric

4

What is the secretory component of the IgA?

protective hinge area where the dimer might be cleaved

5

What is the major immunoglobin in blood?

IgG

6

Where do you find IgD immunoglobins?

on surface of b-cells

7

What is a baby born with?

Maternal IgG

8

What does cross linking of IgE on mast cells lead to?

Degranulation, histamine and other substances released that cause allergic reactions
*must be crosslinked

9

What are 3 methods by which antibodies mediate humoral immunity?

1. Neutralization-prevent bacterial adhesion
2. Opsonization-antibody promotes phagocytosis
3. Complement Activation-antibody activates complement, enhances opsonization and lyses bacteria

10

IgM, primary or secondary response?

Primary

11

IgG, primary or secondary response?

Secondary

12

IgD usually membrane form or plasma form?

membrane

13

What does aggregation of immunoglobulin on bacterial surface allow for?

-cross linking of Fc receptors
-activation of macrophage
-phagocytosis and destruction of bacterium

14

What is a crucial time for babies, because maternal IgG antibody is almost gone and they havent started making much of its own IgG?

3-9 months

15

Is a vaccine as good as having the disease in terms of half life length of serum antibody?

NO

16

Polyclonal vs. Monoclonal antibodies

Polyclonal: multiple antibodies, directed against different epitopes made by separate clones of B-lymphocytes
ex: IVIG (intravenous immunoglobin)treatment for inflammatory disease

Monoclonal: single B-cells that make a single kind of antibody, can be immortilized in vitro and used as a continual source of a specific monoclonal antibody
ex: tumor specific antibodies to treat cancer

17

What type of rearrangement do Ig genes undergo?

somatic DNA recombination

18

What exons encode the variable region in the light chain?

V and J exons

19

What exon encodes the constant region in the light chain?

a C exon

20

What exons encode the variable region in the heavy chain?

V, D, J exons

21

What exon encodes the constant region of the heavy chain?

multiple C exons

(membrane associated: transmembrane and cytoplasmic)

22

Where are Ig genes only expressed?

B-lineage cells

23

what is the order of Ig gene rearrangement
light chain
heavy chain

1. heavy chain DJ
2. heavy chain VDJ (critical control point)
3. light chain VJ