Final tidbits Flashcards
By how much are cells outnumbered by bacteria?
10:1
2 types of surface defence enzymes?
- lysozyme (saliva, sweat, tears)
- pepsin (gut)
What are the type 1 + 3 interferons?
alpha, beta, lambda
What are 4 actions of type 1 and 3 interferons?
- activates NK cells
- upregulates MHC, Mx proteins
- activates RNase L, PKR
- induces anti-viral state
What is the key type 2 interferon?
IFN-gamma
What are 3 actions of IFN-gamma?
- proinflammatory
- Th1 cytokine
- immune interferon
Which cells are an important early source of cytokines?
NK cells
Which cells are an important early source of cytokines?
NK cells
What are 4 key roles of antibodies?
- neutralisation
- opsonisation
- complement activation
- may trigger cell-mediated cytotoxicity (ADCC)
What are 4 strategies of viruses to evade the immune response?
- block IFN induction
- decoy IFN receptors
- perturbation of IFN signalling
- downregulate ISGs - IFN-stimulated genes
What is the key chemokine that attracts neutrophils?
IL-8
Which chemokines do eosinophils respond to?
eotaxin, RANTES
What is a key role of IFN-gamma?
released by T cells to enhance activation of macrophages
What may be the effects of TNF-alpha?
fever and weight loss, systemic effects associated with infection
What stops NK cells from becoming active?
MHC I complexes
What is meant by neutralisation of a pathogen e.g. as performed by antibodies?
block surface receptors, prevent it from attaching to or infecting host cells
What is the form of antigen which is recognised by T cells?
sequences of peptide from digested antigens presented by APCs (NOT molecule surface/shape/charge)
Which T cells recognise peptide presented by MHC II?
CD4 i.e. T helper cells
Which cytokines are released by Th1?
IFN-gamma, TNF
Which cytokines are released by Th2?
IL-5, IL-4, IL-9 and IL-13
Which cytokine is released by Th17?
IL-17
What are acute phase proteins defences against, bacteria or viruses?
bacteria - opsonins, bind in nons-specific way to bacteria
