Overview of the adaptive immune system Flashcards
What is the adaptive immune system?
= part of the immune system that has enhanced rapidity, potency or specificity as a consequence of previous events (exposure or vaccination)
Anamnestic response - memory is the key element
What is the purpose of the adaptive immune system?
Protection from and defence against pathogens
- Opportunity to have effectors ready which are specific and potent
- Some pathogens stick around and need controlling - ‘latency’ - controlled by effectors
Role in malignancy surveillance
Liked to damage healing and repair
How do we spot pathogens?
Generic recognisable features - PAMPs
Presence is associated with damage
- Damage-associated molecular pattern molecules (DAMP)
- There is co-stimulation of CD28 to confirm the pathogen
Previous exposure
Autoimmunity - self vs non-self (it shouldn’t be there)
What are examples of innate and adaptive cells invovled?
How can you describe lymphocytes?
- White cell, small with large nucleus
- T and B cells
- Can either be:
- naive/memory
- immature/mature or differentiated
- They: helper, cytotoxic, regulatory and antibody-producing
- Surface markers they express: cd4, cd8 cd28
- Type of receptor: Ig class for B cells/ ab vs yg for T cells
- What they produce: TH1 or TH2
How is clonal selection used in adaptive immunity?
One clone - one specificity
- B-cells - one cell, one antibody
- Defined by their antibody
- May class switch/undergo affinity maturation but always Ig
- T-cells - one cell, one T cell receptor
- Selection and expansion of that clone with or without differentiation
- Retention in memory of clonal progeny
- Continued protection
- Continued production of antibody (B cells and plasma cells)
- More rapid specific secondary responses (B and T cells)
What happens in the primary and secondary response in B cells?
How do the lymphocytes have different receptors?
What is the B cell repertoire selection?
- Positive selection
- Receptor editing
- Negative selection to make sure they’re not recognised in cell
- Antigen recognition leads to proliferation to differentiation
- Activated B cells transform into plasma cells