Introduction to Immunology Flashcards
What are the roles of the immune system? - what is it’s normal function
- Distinguish self and non self
- Identify danger signals - secondary inflammatory signals
- Must balance between clearing pathogen and causing collateral damage
Explain the concept of the pathogen vs. Host Arms race:
- Pathogen and host exert selection on one another
- Pathogen reproduces faster than host so evolve fast
- Host relies on flexible immune response
- Polymorphic genes HLA and KIR involved in immune system (selected for by exposure of population to infectious disease)
What are the advantages and disadvantages of the two strategies used by the immune system?
Strategy 1: germline encoded:
Pro: many cells have same receptor, so rapid, effective response
Con: limited receptor diversity, so some not recognized
Strategy 2:
Pro: massive diversity
Con:
- initially few cells express specific receptor so must expand for response, takes time
-Some receptors express self so autoimmune potential
Name the two types of triggers and give examples for each
PAMP- pathogen associated molecular patterns
- dsRNA in cytoplasm, molecular patter
- Receptors TLRs
DAMP- danger associated molecular pattern
- Monosodium urate, high extracellular ATP, 02 species
- Receptors: NLR, RLR, A1M2
- DNA
- ECM fragments
What is an epitope?
Antigen receptor binding site
Compare and contrast innate and acquired immunity
see notes
What does the innate system do?
- Destroy invading NA in cytoplasm
- Signally recruitment of immune system cells
- Activates interleukins: activates inflammatory pathway
- Evokes type 1 interferon
What is the time course in a primary immune response to a virus?
- Early peak of type 1 interferon - interferes with virus replication
- Peak of natural killer cells: recognize infected cells and lyse them
- Reduce virus replication to eliminate need adaptive IS response
- Increase in CTL
- Start producing antibodies against virus
What is the acute phase inflammatory response?
- Fever - INK1
2. Acute phase protein production by liver
Define acute phase protein:
class of plasma protein whose plasma concentration increases or decrease in response to inflammation
Name some acute phase proteins:
- C- reactive
- Serum amyloid
- Manna binding lectin: soluble pattern reocgniiton recptros, helps activate complement system (binds to mannose sugar not often found in mammalian cells)
What are cytokines and their function?
- large family of soluble molecules (proteins)
- Binds to receptors and send signal to cell to alter pathogen gene expression
- Important for lymphocyte proliferation
What are the characteristic of the adaptive immune system?
- Specific foreign antigen
- Can form memory cells
- Requires priming (exposure to infection agents first)
Define antigen
molecule that react with antibody or T cell
Define immunogen
antigen that can initiate immune response
Antibody:
immunoglobulin molecule in blood and body fluids binding to specific antigen
What does each type of receptor recognise?
- BCR: membrane bound and binds to intact antigen
- TCR: only bind to digested antigen fragments
Where are naive lymphocytes found?
98% TC in lymph, 2% in blood
What happens when the antigen is removed
- Most lymphocytes that have proliferated will die after fulfilling function
- Some survive as memory cells
