Lec1-3 Overview and Innate Immunity Flashcards
What is mech of multiple slcerosis
- immune attack against myelin basic sheet that insulates neurons
Is innate or adaptive immune more specific
adaptive
Is there more diversity in receptors of innate or adaptive?
Adaptive - due to somatic recombination of gene segments
What are 5 main components of innate immunity?
- barriers to infection [epithelium/skin]
- phagocytes
- dendritic cells
- NK cells
- complement
What make cell type make up pus?
neutrophils
What is principle function of B lymphocytes in immune
- mediate humoral immunity
What is the principle function of T lymphocytes in immune
Mediate cell-mediated immunity
Are natural killer cells in innate or adaptive immune?
innate
What is the principle fcuntion of dendritic cells in immune?
= act as antigen presenting cells, initiated T cell response
What is the principle function of follicular dendritic cells?
- display antigens to B cells in humoral immune response
What types of barriers involved in innate immune
- physical barrier to infection [skin]
- killing of microbes by locally produced antibiotics
- killing of microbes by intrapepithelial lymphocytes
also: resident flora, chemical barriers
Are neutrophils or macrophages short lived?
neutrophils!
What are PAMPS?
- pathogen associated molecular patterns
- recognized by toll like receptors (a type of pattern recognition receptor [PRR] ) on surface of DC/macrophage and trigger activation
Endpoint of TLR signalling cascade
Part of innate immune
- increase expression cytokines/adhesion molec –> acute inflamation, stimulate adaptive immune
- increase production IFN –> antiviral state
What are NLRs? Endpoint?
NLR = nod-like receptor
- release IL-B: fuel acute inflammation and fever
5 Characteristics of inflammation
- heat
- redness
- swelling
- pain
- loss of function
Macrophages as sentinels
- recognize pathogens or cell death product
2 Natural Killer Cell Functions
- Nk cell sees infected cell ad kills it
- NK cell binds macrophage that has phagocytosed molecule, releases IFN-gamma that activates macrophage to kill phagocytosed microbe
How are NK cells inhibited?
- inhibitory receptor on NK cell binds self class I MHC-self peptide complex on normal cell so not activated and does not kill
- when NK binds virus infected cell that has little class I MHC expressed, no inhibitory receptor so kills cell
3 Paths of complement activation
- Alternative: microbe initiates activation
- Classical: microbe bound to antibody initiates
- Lectin: microbe bound to mannose-binding lectin initiates
Which pat of complement peptides gets deposited on the microbe?
C3b
What happens to C3 in complement?
- C3a breaks off and stimulates inflammation
- C3b is deposited on microbe and aids in phagocytosis
Type 1 Interferon [IFN] pathway? 3 Mechanisms of viral inhibition
- IFN produced by virus infected cell
- binds IFN receptor on uninfected cell
- Mechanisms of blocking viral replication
1. degrades viral DNA
2. inhibits viral gene expression
3. inhibits viral protein synthesis