innate immunity and antigen

Question 1

what promotes phagocytosis?

Answer 1

• receptors for common bacterial cell wall components (PAMPs)
• receptors for C3b complement cascade
  
  • complement-mediated opsonisation
• receptors for Fc region antibodies
  
  • immune complex-mediated opsonisation

Question 2

lymphocyte effectors

Answer 2

• antibody production = B lymphocytes
• antigen- specific cytotoxicity = CD8 T lymphocytes
• natural killer lymphocytes
• antibody-dependent cellular cytotoxicity = K lymphocytes

Question 3

lymphocyte regulators

Answer 3

cytokine production = CD4 T lymphocytes

• Th1 - viruses, bacteria, intracellular agents
• Th2 - parasites, allergies, multi-cellular
• Treg - down regulation
• Th17 - mucosa and inflammation

Question 4

describe the transport from innate to adaptive immunity

Answer 4

moves to secondary lymph organs

1. antigen uptake by APCs
2. transport through lymphatics
3. antigen held in lymph node
4. antigen-specific cells recruited

Question 5

APC functions

Answer 5

• antigen collection and transport
• antigen concentration
• antigen processing
• present processes antigen to lymphocytes
• Co stimulation
  - proinflammatory cytokines
  - surface molecules

Question 6

exogenous vs the endogenous pathway

Answer 6

exogenous pathway
 - peptides derived from ingested material
 - only specialised APCs
     (B cells, dendritic)
 - presented by MHC2

endogenous pathway
- peptides derived from cytoplasmic proteins
- normal metabolism
(viral peptides, modified self-peptides)
- presented by MHC1

Question 7

acute phase proteins

Answer 7

• molecules increased in the blood during acute phase of infection
• released from infection-activated danger signals, tissue trauma
• produced in the liver

Question 8

action of complement

Answer 8

• increase vascular permeability (increase fluid leak, increase neutrophil entry)
• chemotaxis
• opsonisation (C3b)