B and T Cells Flashcards
1
Q
Maturation and education of lymphocytes
A
- Primary lymphoid organ function
2
Q
Differentiation of B and T cells after foreign exposure into effector cells
A
- Secondary lymphoid organ function
3
Q
Effector-B Cells
A
- plasma cells
- make antibodies
4
Q
Effector T cells
A
- T-helper cells (CD4)
- B and T cells - Cytotoxic T-lymphocytes (CTL; CD8)
- kill infected cells and tumor cells
5
Q
Where do all T-cells mature?
A
- in the thymus
6
Q
What are the ONLY somatic cells where somatic gene rearrangement occurs?
A
- B and T cells
7
Q
Central Tolerance Steps
A
- Positive Selection
- T cells must recognize self-MHC molecules to survive
- > if they do not, apoptosis occurs - Negative selection
- T cells must not recognize self-antigens to survive
- > if TCR binds self-antigens, apoptosis occurs
8
Q
Survivors of Central Tolerance
A
- they mature and express CD3 (all T cells) and EITHER CD4 OR CD8 and then leave
1. CD3/CD4 - T helper cells
2. CD3/CD8 - cytotoxic T-lymphocytes (CTLs)
9
Q
In birds where does B-cell maturation and selection occur?
A
- in the bursa
10
Q
In mammals, where does B-cell proliferation and somatic cell gene rearrangement for BCR repertoire generation occur?
A
- in the bone marrow and payers patches
- > negative selection of self-reactive B-cells = apoptosis
11
Q
Antigen binding component of TCR and BCR
A
- has had gene rearrangement
12
Q
Signaling component of TCR and BCR
A
- signal transduction
- no gene rearrangement
- CD3 with TCR -> signal transduction
- CD79 with BCR -> signal transduction
13
Q
Weak affinity/binding
A
- insufficient to activate the lymphocyte
14
Q
The strength of binding between an antigen and the receptor
A
- affinity
15
Q
TCR vs BCR
A
- TCR
- MHC restricted
- processed linear peptide antigens
- never secreted - BCR
- sees epitopes on unprocessed antigen free in solution
- secreted BCR = antibody!
- antibody = BCR minus membrane anchor
