Adaptive immunity-T cells Flashcards
1
Q
A
2
Q
TRUE or FALSE: Adaptive immunity is the 3rd line of defence
A
TRUE
- Lymphocytes – B and T cells
- Similar effector mechanisms to innate immunity
- Unique system of recognition
3
Q
Describe pathogen recognition– innate immunity
A
- A fixed repertoire of receptors and soluble molecules (PRR)
- All components are inherited
- New variants rarely arise
- Overall strategy
- recognise pathogenic structures (PAMPs), or
- detect alterations in infected or damaged cell
4
Q
Describe pathogen recognition– adaptive immunity
A
- Each lymphocyte (cell) expresses just one molecular type of receptor
- B cells – B cell Receptor (BCR; membrane immunoglobulin)
- T cells – T Cell Receptor (TCR)
- The receptors are made by gene rearrangement so we all have millions of different specificities
- Each cell is a clone with a unique receptor
5
Q
State 3 advantages of the adaptive immunity
A
- Precise targeting
- Memory cells
- Recognize “new” pathogens
6
Q
Describe the B cell receptor
A
7
Q
Describe the plasma cell receptor
A
8
Q
Describe the T cell receptor
A
9
Q
How is receptor diversity generated?
A
By gene rearrangement
10
Q
Explai why receptors of adaptive immunity are highly specific
A
- During developmet, progenitor cells give rise to large numbers of circulating lymphocytes, each having a different form of cell surface receptor
- The recptors of only a few circulating lymphocytes interact with any given pathogen
- Pathogen-reactive lymphocytes are triggered to divide and proliferate
- Pathogen-activated lymphocytes differentiate into effector cells that eliminate the pathogen
11
Q
Describe the advantage confered by highly specific antibodies
A
Antibodies made during infectin with measles virus bind to the birus and prevent reinfection with measles virus
Antibodies made during infection with measles virus do not bind to influenza virus
