Properties of Human Ig Classes

Question 1

What are the 4 biological functions of IgG?

What 3 cells have FcY receptors?

Answer 1

Biological Functions:
1. Fixes (activates) complement
2. Opsonization
3. ADCC by NK Cells
4. Crosses Placenta
Cells with FcYRs:
1. PMNs = Granulocyte = eosinophils, neutrophils, mast cells, and basophils
2. B Cells
3. Monocytes - Macrophages - NK cells

Question 2

What is the biological function of IgA?

What 3 cell types have Fcalpha receptors?

Answer 2

Biological function:
1. Mucosal Immunity
Cells W/ Fc-aR
1. PMNs
2. B cells
3. Monocytes

Question 3

What are the 2 biological functions of IgM?

Cells w/ Fc receptors?

Answer 3

Bio Funct of IgM:
1. Fixes (activates) complement system
2. B cell antigen receptor
Cells W/ Fc receptor:
NONE

Question 4

What is the biological function of IgD?

Cells w/Fc receptors?

Answer 4

Bio funct for IgD:
1. B cell antigen receptor early in B cell development
Cells w/ Fc receptor:
NONE

Question 5

What are the 2 biological functions of IgE?

3 Cells with Fc-epsilon receptors?

Answer 5

Bio Funct of IgE:
1. Basophil and Mast cell Degranulation (Think allergic response)
2. ADCC by Eosinophils
Cells w/ Fc-epsilon receptors:
1. Mast cells
2. Basophils
3. Eosinophils