13. Adaptive Immune Response Part 2 Flashcards
Where are B and T lymphocytes produced and matured?
Produced in bone marrow
T cells mature in thymus
B cells mature in tissues following contact with antigen
Where do B and T lymphocytes accumulate?
In key lymphoid tissues
- mucosa-associated lymphoid tissue (MALT)
- lymph nodes
- spleen
What is the antigen recognition receptor in T lymphocytes?
T cell receptor (TCR): alpha and beta chains
CD3 complex
Accessory molecules (CD4 or CD8)
What are the forms of antigen recognised by T lymphocytes?
Peptides displayed by MHC molecules
What are the different subtypes of T lymphocytes?
Helpers T cells (CD4+) recognise peptide presents by MHC class 2 molecules Cytotoxic T cells (CD8+) recognise peptide presented by MHC class 1 molecules
What is the role of costimulation in activation of T lymphocytes?
Look at notability
What is the activation of T helper cell response (CD4+ T cells)?
Look at notability
What are the effector functions of CD8+ T cells?
See notability
What are the antigen recognition receptors on B lymphocytes?
B cell receptor or BCR: membrane bound antibodies
Unique specificity for each cell
What forms of antigens are recognised by B lymphocytes?
Macromolecules
Small chemicals
What signals are required for activation of B lymphocytes?
1st signal: BCR engagement - signal transduction, antigen processing and presentation, increased B7 costimulators
2nd signal: TCR engagement - antigen specific, role of B7 costimulators
3rd signal - cytokines, CD40 activation
What is the outcome of B lymphocyte activation?
Antibody production - IgM production is T helper independent, IgG, IgA, IgE production is T helper dependent
Affinity maturation in antibody response - prolonged or repeated exposure
Memory B cells - upon re-challenge can give a faster stronger and longer antibody response
Antibody heavy chain class switching
See notability
What are the characteristics of the antibody response?
See notability
What are the effector functions of IgG?
Fc-dependent phagocytosis
Complement activation
Neonatal immunity
Toxin/virus neutralisation
