FMS Week 8 Flashcards
Immunology
What are T regulatory cells?
suppress Th1 and Th2 and have an anti-inflammatory effect
What is the general result of deficiency in classical pathway components?
autoimmune disease
What is IL-4?
the major Th2 cytokine; activates Th2/suppresses Th1 production; promotes IgE production (parasites)
What additional binding is required for B-cell class switching in T-cell dependent activation?
CD40 (B-cells) to CD40 Ligand (T-Cells)
What does CRP bind to?
CRP joins the C1 complex to Bacterial polysaccharides
Describe the classical complement pathway
The C1 complex binds to CRP; the attaching of 2 adjacent Fc complexes removes C1-inh, activating C1r & C1s (proteases); C4 and C2 are cleaved; C4b and C2b create a C3 convertase; C3 convertase generates C3b
What proteins make up the membrane-attack complex?
C5b, C6, C7, C8, C9
what are interleukins?
cytokines that travel between leukocytes
Which antibodies are dimers?
IgA
what are cytokines?
cell signalling proteins that stimulate inflammatory response
What are the 3 key functions of macrophages?
phagocytosis, cytokine production, antigen presentation
What are the functions of antibodies?
opsonization, neutralization, activating complement
What are kupffer cells?
macrophages of the liver
What is DAF?
decay accelerating factor (CD55); disrupts C3b attachment in formation of C5 convertase; protects host cells from late complement pathway
What is the secretory component?
the bridge that links IgA monomers as they pass through epithelial cells creating a dimer in secretions
What are the key roles of Natural Killer Cells?
Kill virus-infected cells; produce INF-γ to activate macrophages
what cells are agranulocytes?
Lymphocytes (NKC, T & B) and monocytes (macrophages)
What are the properties of C5a?
Anaphylatoxin and neutrophil chemotaxis
What types of molecules do T-cells recognize?
only peptides presented by APCs
what is the difference between mast cells and basophils?
basophils are found in the blood stream, and mast cells are in the tissue
What is IL-1?
a cytokine released by macrophages; increases synthesis of endothelial adhesion molecules allowing neutrophils to enter inflamed tissue; acts as an endogenous pyrogen by acting on the hypothalamus
What are PAMPs?
pathogen-associated molecular patterns; present on many microbes but not human cells, used by the immune system to recognize pathogens
Describe the alternative complement pathway
Spontaneous conversion of C3 to C3b; stabilized by amino and hydroxyl groups on bacterial surfaces; stabilized C3b binds to Factor B (C3bB); Factor D clips Factor B to make C3bBb (C3 convertase); C3 convertase can make more C3b leading to rapid accumulation on surfaces
How do nucleic acids act as PAMPs?
DS-RNA and Unmethylated DNA are characteristic of pathogens and recognized by the innate immune system