The Immune cell Flashcards
How are macrophages activated?
Recruited as monocytes from blood
Tissue specific differentiation
Recognise Pattern Recognition Receptors or opsonic receptors
What pattern recognition receptors do macrophages detect?
CD36,
mannose receptors
dectin-1
How is opsonisation targetted?
Fc portion of antibody detected by clustered receptors
ITAM phosphorylation of Src
Syk kinase acts on Wiskott-Aldrich syndrome protein
Arp2/3 activation causes actin to form pseudopods
What is the process after phagocytosis?
Early and late endosome formation
Fusion and maturation with lysosome
Rab5/7 GTPases cause movement to perinuclear position
What anti-microbial properties does the phagolysosome have?
lactoferrin for nutrient deprivation defensins for permeablisation hydrolases ROS/NOS Acidifcation
How does TB evade phagocytic degradation?
Inhibits Rab5
SapM hydrolyses PI3P
PI mannosides prolong endosome fusion
How is TB degradation induced?
Interferons cause autophagy
How does Listeria monocytogenes evade degradation?
Listeriolysin forms pores to release H+/Ca so no maturation
PLPs digest phagosome to release bacterium into cytosol
What do Cytotoxic T cells recognise?
MHC Class 1 molecules presenting antigens
How do cytotoxic T cells cause cell death?
Recognise MHC1
Dock with ICAM and Leukocyte Function Associated Antigen 1 which seal immunological synapse
Microtubule organising centre and secretory lysosomes polarise to synpase
SNARE mediated docking
Perforing digests cells wall to release granzymes and hydrolases
What diseases are associated with T killer cells?
Familial haemophagocytic lymphohistiocytosis Type 2 and Type 3
Griscelli Syndrome Type 2
What are the causes of FHL2?
Mutated perforin
What causes FHL3?
Mutated Munc3/4 SNARE
What is Griscelli syndrome?
Mutated Rab27a so no trafficking/exocytosis
Partial albinism observed
