Adaptive Immunity 1 Flashcards
what is adaptive immunity?
- SPECIFIC & ACQUIRED response
- Consists of cell-mediated (activation macrophages, NK cells, antigen-specific cytotoxic T-cells CD8+) and antibody responses
What are the 3 receptors in adaptive immunity?
- T cell receptor (TCR)
- B cell receptor (Immunoglobulins [Ig])
- Major histocompatibility complex (MHC Proteins)
Where are T-cells derived from and where do they mature?
Derived = Bone marrow Mature = Thymus
How do T cells recognise peptides presented by APCs?
Through the T cell receptor (TCR)
What is a CD4+ cell and function?
Helper T cell, help and support other immune cells fight threats
What is a CD8+ cell and function?
Cytotoxic/Killer T cell, destroy our own cells which have become infected
What are the two classes of T-cell receptors?
1 alpha and 1 beta chain receptors
What is thymic education?
where undifferentiated T-cells enter thymus become specialised (CD4+ & CD8+) and undergo either positive or negative selection
What is positive selection?
The process which ensures T-cells react against antigens. If they dont;
T-cell apoptosis
what is negative selection?
The process which ensures T-cells DONT react against SELF-ANTIGENS (your bodys own). If they do;
T-cell apoptosis
Where do T-cells go after thymic education?
Leave the thymus and circulate in blood/lymphatics
How are naive T-cells activated/differentiated?
‘Priming’ through 3 different signals;
Signal 1: activation of T-cells
Signal 2: survival & clonal expansion of T-cells
Signal 3: differentiation into subsets of effector T cells
