Lecture 3 Flashcards
3 main functions carried out by T cells
- Provide assistance to other cells in the immune system (Th cells)
- Limit excessive or undesired immune responses (Tregs)
- Kill infected cells (CTLs)
Features of 𝛾𝛿-T cells
- Found in high numbers in mucosal tissues
- Form a large percentage of resident T cells
- Don’t have classical TCRs
- Important as first responders (express PRRs & produce cytokines)
- Not fully understood
Main role of plasma cells
Produce lots of antibody specific to antigen
How do T cells recognise antigen?
T cells recognise specific antigenic peptides that are presented by APCs bound to MHC molecules by the TCR on their surface
MHC Class I molecules present antigens to __
CD8+ T cells
MHC Class II molecules present antigens to __
CD4+ T cells
What does CD28 on T cell surface recognise?
CD80 (B7-1) or CD86 (B7-2) on surface of APC
CD3 is a co-receptor on T cell surface needed for __
signal transduction
What is the antigen receptor on B cells?
a membrane-bound immunoglobulin (IgM or IgD)
Major advantage that T cells have over B cells
T cells can inspect antigens that are largely confined within cells and are therefore inaccessible to Ig
2 main parts of the antibody molecule
- Variable (Fab) region: Ag recognition
- Constant (Fc) region: effector function
Can TCRs recognise free antigen?
No, but BCRs can recognise soluble Ag draining into the LN
What happens when B cells clonally expand?
Differentiation into plamsa cells, which generate soluble Ab specific to that Ag
What type of DC can ‘capture’ an Ag on its surface and present it to B cells in the lymph node?
follicular
TCR and BCR specificity is generated through…
somatic recombination events