Flashcards in PA20292 Christine Edmead Deck (162)
2 proinflammatory cytokines to remember;
IL1 (interleukin 1)
These enhance Inflammatory response by drawing WBC's out blood Into tissue to fight the antigen.
What do peritoneal lymphocytes secrete antibodies against?
Some features of neutrophils?
Large multi lobed nucleus
Lot of organelles
Contain antmicrobial enzymes
Features of macrophages?
Lots of organelles
Help with antigen presentation
Features of dendritic cells?
Membrane protrusions; engulf antigens
What do dendritic, macrophages and neutrophils have in common?
They are reactive oxygen and nitrogen species.
All engulf the antigen
What do natural killer cells do?
Lysis of virally infected cells
Recognise viral antigens on cell surface
What are both natural killer cells and dendritic cells?
Interfere with viral reproduction
Basic job of pattern recognition receptors?
Recognise structures on microbes that aren't present on self proteins.
Present of neutrophils macrophages and dendritic cells.
What are the 4 types of patter recognition receptors?
Mannose receptors- recognise sugars
Receptors for opsonins- enhance phagocytosis
Toll like receptors- recognise proteins on AG
7transmembrane alpha helical receptors - recognise peptide fragments
What happens when an antigen binds to pattern recognition receptors?
Phagocytosis by macrophages/ neutrophils
Cell may be killed by NK cells if virus
Presentation of fragments of AG to T cells by APC's
What kind of things will toll like receptors respond to?
LPS- KEY ACTIVATORS
These all tell them that the microbe is foreign
What does binding to toll like receptors result in?
Up regulation of inflammatory gene expression! Ie INFLAMMATION
What do TNFa , IL-1, E-selectin, and iNos result in?
Enhance white blood cell movement from blood to tissue to create inflammation
What is IL-12? Secreted by?
By macrophages and dendritics
T cell stimulating factor
Lipopolysaccharides are also known as....
What are LPS a product of/ found in?
Cell walls of gram NEGATIVE bacteria
What does LPS present of the surface of some bacteria stimulate?
Local and systemic inflammation
WBCs leave blood to enter tissues
Increase tissue fluids
Increase cellular activators enzymes
Activate macrophages and neutrophils
Macrophage activation= cytokine release
Reactive oxygens burst- involved with digestion of AG
What does excessive LPS stimulation cause?
Systemic inflammatory response syndrome (fever, septic shock, too much inflammation)
What are the effects of microbes binding to toll like and mannose receptors?
Production of CYTOKINES
Reactive oxygen intermediates; v. Toxic to microbes= kill the microbe
What can bind to 7 alpha helical transmembrane receptors?
N formyl methyl peptides (bacterial peptides)
Effect of binding to 7 alpha helical transmembrane receptors?
Increased integrin avidity (higher affinity of integrin receptors)
Stimulated migration into tissue
Does not result in killing of the microbe!!!!
Must abundant type of WBC?
Small so they can easily enter tissues
What do natural killer cells recognise microbial markers on the surface of?
Already infected cells usually viral (not on microbes)
Recognise through patter recognition receptors
How do NKCs work?
Perforins released- make holes in target cell membrane
This allow entry of granzyme (digestive enzyme)
Infected cell is sacrificed and dies by apoptosis
Destroys viral load (target cells for NKCs are virally infected)
Apoptosis not phagocytosis!
How are NKcs activated ?
IL-12 from macrophages
Activates NKCs, they secrete IFNy
IFNy Feeds back and activates macrophage
(positive feedback loop)
How is NKCS actions inhibited?
By MHC Class I binding to inhibitory receptors on surface of NKCs.
Stops it invading any uninflected healthy self cells.
M N O P.... alphabet.....
Macrophages and neutrophils ..... Phagocytosis!
Natural killer cells cause Virally infected cell to die by APOPTOSIS, due to entry of granzyme through pores made by perforins.
Not phagocytosis!!!! ( like macrophage and neutrophil )