infection and immunity

Question 1

immune response to bacteria

Answer 1

recognition of PAMPs -> inflammatory process:

• vascular permeability changes
• phagocyte recruitment
• acute phase protein induction
• local temp change

-> phagocytosis, complement activation

Question 2

antibodies and complement

Answer 2

• prevent adherence, reduce mobility (bind to flagella)
• enhance bacterial destruction
• enhance phagocytosis
• some bacterial capsules resist opsonisation (thus AB and complement required)

Question 3

immune response to viruses

Answer 3

1. initial production of anti-viral cytokines (IFN) signals other cells to enter transient anti-viral state
2. IFN up-regulates NK activity
3. cytotoxic T cells (antigen-specific); delay due to activation by T cells
4. antibodies (protect against viral spreading from cell-to-cell, preventing re-infection)

Question 4

microbial factors

Answer 4

• type of organisms
• virulence factors
• route of entry
• amount (degree of exposure)

Question 5

host factors

Answer 5

• integrity of innate barriers
• adaptive immune competence
• HLA, Ig, TCR genes
• previous exposure
• other infections

Question 6

what are cytotoxic T cells effective against

Answer 6

intracellular protein antigens
- only useful when looking at presented antigens by HLA class 1 molecules
e.g. virus infection (infected cells)
tumour cells
transplanted organs

Question 7

describe the role of pattern-associated molecular patterns (PAMPs)

Answer 7

triggers local inflammation

• vascular permeability changes
• phagocyte recruitment
• acute phase protein infuction
• local temperature change

leads to phagocytosis and complement activation

Question 8

what is a key early non-antigen specific way of dealing with virus infections

Answer 8

• the production and release fo the interferon glycoproteins

- they induce a transient inter-viral state making it more difficult for virus to infect and grow within cells