Shared Flashcard Set

Details

Innate Immune System
Chapters 20-23
40
Immunology
Undergraduate 2
03/24/2012

Additional Immunology Flashcards

 


 

Cards

Term
What are the roles of neutrophils?
Definition
Most numerous WBC, migrate rapidly to sites of infection, kill pathogens via phagocytosis
Term
Difference between monocytes and macrophages?
Definition
Monocytes are blood derivates and macrophages are activated in tissues
Term
What are examples of fixed macrophages?
Definition
Kuppfer cell in sinusoids of liver, function to phagocytose particulate matter
Term
What is the most important cytokine for phagocyte recruitment?
Definition
IL-8
Term
What does IL-8 do specifically?
Definition
Modifies neutrophil integrins, acting as chemokines to bind endothelium
Term
What are three types of receptors phagocytes have?
Definition
TLRs - danger signals and cytokine producion
C lectin receptors - Recognizes sugars on mammalian cells, activates macrophages
Complement receptors - bind pathogens, stimulate inflammatory response
Term
how do phagocytes recognize IgG?
Definition
Through Fc receptors, as IgG help to activate phagocytosis of internalized antigens
Term
What is the respiratory burst?
Definition
Enzyme pathways that after phagocytosis, help to produce toxic molecules and kill pathogens. Hydreogn peroxidases, HOCL and NO
Term
What molecules are important in lysosomal degradation of pathogens?
Definition
Defensins and lactoferrins are released into phagosome, deprives it from iron or punches hole into bacteria
Term
What is the Acute phase response? Cells and cytokines involved?
Definition
Initial reactions to infection or virus, macrophages secrete Il-1, IL-6, TNF-a to increase production of complement

Increase body T via hypothalamus (TNF-A)
Term
What is the link between macrophages and adaptive immune system?
Definition
IgG is the best opsonizer of bacteria, allows macrophages to kill. Macrophages and IgG are sustained by Th1 responses, while IF-G supports macrophages during chronic inflammation, unlike IF-A/B which have viral functions
Term
Why are worms such an issue to the human body?How are they dealt with?
Definition
Resistant to natural barriers like low ph and proteolytic digestion. Mast cells and eosinophils evolved to respond to worms
Term
What cytokines influence Th2 production?
Definition
Th2 response under influence of Il-4, Il-3,Il-6.
Term
Describe the allergic response
Definition
Antigen released by worms stimulate Th2 and B cells- class switching produces IgE, binds to mast cells. Next encountering of antigen leads to mast cell degranulation. Bound to mast cell by Fc prtion.
Term
What do mast cell granules contain?
Definition
Tryptase, chymotrypsin - increase mucus, activate complement and kinin pathways
Term
What cytokines are released in mast cell granules?
Definition
TNF (diapedesis), IL-4 (other th2 cells), Il-3,5 (eosinophil production)
Term
What are the differences between eosinophils and mast cells (2)
Definition
Specifically recruited to tissue for inflammation, granules contain toxic substances (not just enzymes). Triggered by IL-3,5. HOCL released, and major basic protein (damages parasite outer surface)
Term
What is a type 1 hypersensitivity reaction?
Definition
Allergic hypersensitivtiy caused by innocuous antigens like pollens
Term
What are two main roles of NK cells?
Definition
Excellent killers of cells infected with viruses
Stimulate adaptive immune response (similar to macrophages)
Term
How do NK cells function?
Definition
Recognize when MHC expression is downregulated, release toxic chemical like granzyme, perforin and fas ligand to kill cell.
Term
Why aren't NK cells considered adaptive?
Definition
Don't have rearranged T cell molecules, but phenotypically identical
Term
How do NK cells interact with IgG?
Definition
Fc receptors recognize IgG bound viral antigen, triggers killing (antibody depedant cellular cytotoxicity)
Term
what is the role of Killer immunoglobulin like receptors
Definition
Recognize MHC alpha chains, and when a NK cell recognize virally infected cell, if MHC expression is low, it will kill it
Term
What is a non main function of NK cells?
Definition
Major immune cell of pregnant uterus
Term
How does perforin, granzyme and fas ligand work?
Definition
Perforin - cats like complement and creates a pore in target cells
Granzyme - activate caspase and degrade host proteins
Fas - potent inducer of apoptosis, like TNF receptors (not involved in inflammation)
Term
When NK encounter target cells, how do they communicate with adaptive immune system?
Definition
Secrete IFN-g (TH1 cytokine) and inhibits TH2 cells
TH1 are better at cellular cytotoxicity and intracelullar infection
Term
What is the role of phagocytes and apoptosis? Necrosis?
Definition
NEeded to recognize apoptotis cells and clear the cell remains without stimulating inflammation. However, necrosis often results in inflammatory response
Term
What defines inflammation?
Definition
Redness, swelling and pain.
Edema fluid, pus formation
Term
What is schistomiasis?
Definition
Chronic inflammation mediated by mast cells and eosinophils
Term
What are granulatomas?
Definition
Collections of specialized macrophages surrounded by T cells - delayed hypersensitivity
Term
What three main cytokines does macrophages produce?
Definition
IL-1, TNF -A, GM-CSF. TNF and IL-1 increase adherence of leukocytes to local endothelium.

GM-CSF activate acute phase response
Term
do macrophages preferentially stimulate Th1 responses?
Definition
Yes, through Il-12 and Il-1 sgnalling
Term
How do macrophages and th1 cells create cytokine circle/network?
Definition
Macrophages secrete IL-1 and 12 to activate TH1 cells. Th1 cells then secrete IFN-g which activates macrophages and inhibit Th2 cells
Term
What are two types of tests for TB?
Definition
Skin and Blood tests
Term
How does the skin test for Tb work?
Definition
Intradermal injection of tuberculin (mantous test)
TLRs on dermal macrophages should recognize mycobateria and release TNF. If previous response existed, T cell will be responsive. IF no prior sensitization, no respones. Those vaccinated will produce moderate response
Term
What does the blood test for TB measure?
Definition
IFN-G production by TH1 cells responding to TB peptides
Term
Are adaptive immune system cytokines secreted at high or low levels? why?
Definition
Low levels, like Il-2, as it has very high specificity to TH1 cells and CD8 cells.
Term
What are two features of cytokines in the immune response?
Definition
Redundant (several do the same thing)
Pleiotropism - affect many tpes of cells
Term
What cytokines help develop specialized T cell responses int the gut?
Definition
Gut T cell secrete TGF-B that induces class switches form IGM to IGA
Term
Name two inhibitory cytokines that could dampen immune response?
Definition
IL-10 and TGF-b
Supporting users have an ad free experience!