| Question |
Answer |
| What does terminal deoxynucleotidyl transferase do? |
Addition of nucleotides to DNA during "genetic recombination" in B cells |
| What does Tdt stand for? |
Terminal deoxynucleotidyl transferase |
| Which immunoglobulins are expressed on the surface of mature B cells? |
IgM and IgD |
| What is isotype switching? |
Differentiation of B cells into plasma cells that secrete IgG, IgA, or IgE |
| What stimulates isotype switching? |
Cytokines (IL-4 and IL-5) and CD40-Ligand on T-cells |
| Main antibody isotype in secondary immune response |
IgG |
| Most abundant antibody isotype |
IgG |
| Antibody isotypes which cross placenta |
IgG |
| Antibody isotypes which fix complement |
IgG and IgM in the classic complement pathway
Mnemonic: GM makes classic cars |
| Antibody isotypes which opsonize bacteria |
IgG (and IgA weakly) |
| Main antibody isotype in primary immune response |
IgM |
| Antibody isotypes associated with the J chain |
IgM and IgA |
| Antibody isotypes associated with the SP |
IgA SP = Secretory Protein |
| Antibody isotype with longest half life |
IgG (26 days compared with 5 for IgM, the next longest) |
| Antibody isotype which prevents bacterial/viral attachment to mucous membranes |
IgA |
| Antibody isotype found in secretions |
IgA |
| Antibody isotype which mediates type I hypersensitivity |
IgE |
| How does IgE cause an allergic response? |
Type I hypersensitivity
1. IgE binds to basophils or mast cells
2. IgE binds antigen
3. These cells release histamine and leukotrienes. |
| Which cells have receptors for IgE? |
1. mast cells
2. basophils
3. eosinophils
4. monocytes/macrophages
5. platelets |
| Antibody isotype which mediates immunity to worms |
IgE |
| Least abundant antibody isotype |
IgE |
| Define allotype |
An individual's allele coding for the constant portions of the antibody's heavy chains. |
| Define isotype |
Specific type of chain in an antibody.
Heavy isotypes: alpha, gamma, delta, epsilon, mu
Light isotypes: kappa, lambda |
| Define idiotype |
antibodies of one idiotype share structure of their variable region and thus, antigen binding specificity. |
| Cytokine effects: Interleukin 3 |
Supports the growth and differentiation of bone marrow stem cells (similar to GM-CSF). Most important during early growth.
Mnemonic for first 5 interleukins: Hot T-bone stEAk. bone, as in bone development |
| What releases: Interleukin 3 |
T cells (emphasis on activated T cells) and thymic epithelial cells |
| Cytokine effects: Interleukin 6 |
1. Differentiation and growth of B cells and T cells
2. Systemic effects (Acute Phase Response and Fever)
3. Stimulates Ig production |
| What releases: Interleukin 4 |
Th2 cells |
| Cytokine effects: Interleukin 8 |
1. Major neutrophil chemotactic and adhesion factor
2. Angiogenesis
3. High levels associated with schizophrenia |
| What releases: Interleukin 8 |
1. Monocytes
2. Endothelial cells
3. Fibroblasts |
| Cytokine effects: Interleukin 12 |
1. Promotes differentiation of Th cells into Th1
2. Activates NK cells |
| What releases: Interleukin 12 |
Professional Antigen Presenting Cells:
1. Dendritic cells
2. Macrophages
3. B cells |
