immunology 2 Flashcards
complement system
small proteins synthesized by the liver that help the immune system fight microbial infections
C3a and C5a
chemotactic factors causing inflammation
lectin pathway
lectin can bind to mannose
C3
coating bacterium leading to phagocytosis
mast cells
have large granules that can attack a parasite by producing toxins
macrophages
type of white blood cell that clean the blood from bacteria and dead cells. they eat to kill and stay in tissues
dendritic cells
mobile white blood cell that can move to lymph node and present the antigen it has eaten
phagocytes
know what to eat by phagocytosis receptors, they kill, warn neighbouring cells and help adaptive immunity
PAMP (pathogen associated molecular patterns)
RNA and DNA viruses
DAMP (damage associated molecular patterns)
associated with exposure of cell content that is usually inside
Toll like receptors (TLRs)
most are at the outside of cells for extracellular bacteria, at the inside are for microorganisms that have sneaked in
type 1 interferons
warn neighbouring cells when virus is about to be exposed to other cells
IFN alpha/beta/gamma
upregulate antiviral mechanisms in healthy cells
neutrophils
the DNA changes into chromatin granules which form NETs in which bacteria get trapped
eosinophils
fight big parasites, they bind to them and shower them with toxins
basophils
fights parasites, exocytosis of granules
monocytes
clean up after neutrophils, kill bacteria. function depends on signals
B-cells
attack invaders outside the cell, produces antibodies
antibody
Y-shaped, can bind two antigens
IgG
monomer, opsonisation, complement activation, neutralisation, ADCC
IgE
monomer, activation mast cells and oesinophils
IgM
pentamer, complement activation, neutralisation
IgA
dimer, neutralisation, mucosal defences
T cells
attack invaders inside the cells
T cell receptor
not an antibody, can only recognise antigens presented by MHC
MHCs
membrane proteins that display antigens for recognision by t cells
MHC class 1
expressed by all cells except red blood cells, present smaller antigens from cytoplasm, communicates with CD8 T cell
MHC class 2
expressed by phagocytic cells, present antigens from the outside of cells, present the antigen they have eaten, communictes with CD4 T cells
Treg
recognises itself, autoimmune response
regulatory T cells
can stop activation of antigen presenting cell and T cell, to prevent autoimmune disease
