immunology 2.3: degranulation, NK cells, and phagocytes

degranulation, NK cells, phagocytosis

what are the three important innate responses?

mast cells, basophils, eosinophils, neutrophils

what are the four types of leukocytes that degranulate?

degranulation

release of pro-inflammatory mediators, destructive enzymes, and cytotoxic compounds

histamine, TNF-a, tryptase and chymase, amines

what is released in degranulation within seconds?

leukotrienes and prostaglandins

what are the eicosanoids that are released within minutes during degranulation?

TNF-a, IL-4, IL-5, IL-6, IL-13, IL-17, VEGF

what are the cytokines, chemokines, and growth factors that are released within hours during degranulation?

1. binding to pathogens

2. antibodies

3. complement proteins

what are the three ways that degranulation is mediated?

IgE binds to the outside of a mast cell and when an allergen binds to IgE, histamine is released

what is the mechanism of allergic reactions that results from degranulation?

NK cells

immune system cell that recognizes healthy and unhealthy cells using MHC class I and will destroy infected cells that do not present MHC class I (virally infected, cancer cells)

1. NK cell releases perforins

2. perforins punch a hole in the membrane of the infected cell

3. granzymes from NK cells enter perforin holes and degrade the infected cell

4. infected cell dies by apoptosis

5. macrophage engulfs and digests dying cells

what are the steps of destruction of target cell killing by NK cells?

no

do NK cells degranulate?

releasing cytotoxic granules (perforin, granzymes) or activation of death receptors (FasR, TRAIL-R, TNR-aR)

what are the two ways that NK cells induce apoptosis in target cells?

NK cells

what’s one the leading causes of tissue rejection?

NK cells don’t recognize the MHC 1 receptor and kill healthy allogeneic cells of different HLA-c type

what happens when NK cells interact with a healthy allogeneic cell of different HLA-C type?

1. chemotaxis and adherence of microbe to phagocyte

2. ingestion of microbe by phagocyte

3. formation of a phagosome

4. fusion of the phagosome with a lysosome to form a phagolysosome

5. digestion of ingested microbe by enzymes

6. formation of residual body containing indigestible material

7. discharge of water materials

what are the seven phases of phagocytosis?

1. reaching phagocytosis

2. sinking phagocytosis

3. triggered phagocytosis

   1. like a big wave engulfing pathogen

what are the three forms of phagocytosis?

increase activity and speed of phagocytosis

what are the functions of opsonins?

pathogen associate molecular patterns

molecules associated with groups of pathogens that are recognized by cells of the innate immune system

damage associated molecular patterns

host molecules associated with damaged cells that can initiate and immune response?

pattern recognition receptors

surface/soluble receptors involved in recognition of PAMP/DAMP

• antibody/complement receptors

  • Fca/yR, MAC-1

• c-type lectin receptors

  • mannose receptor

• scavenger receptors

  • bind to pathogen surfaces

• f-mlp receptors

  • bing to bacterial proteins

• toll like receptors

  • TLR-1-10

• NOD like receptors

  • NOD1, NOD2

• RIG like receptors

  • RIG-1, MDA5

• DAMP receptors

  • TLR, NLR, RLR

what are the pattern recognition receptors?

bacteria has f-met to start their DNA sequence and we don’t so we know that bacteria is a target

how does f-mlp receptors help identify bacteria?

1, 2, 4, 5, 6, 9

what TLRs are found on bacteria?

3, 7, 8, 9

what TLRs are found on viruses?

2

what TLR is found on funguses?

bacteria

where are NOD like receptors found?

viruses

where are RIG like receptors found?

NOD 1 and 2

what are the NOD like receptors?

RIG 1, MDA5

what are the RIG like receptors?

identifies things that don’t look right

ex: DAMP receptors senses mitochondria is outside of the cell when it should be inside

what is the function of DAMP receptors?

enzymes within lysosomes, target proteins, lipids, carbs, nucleic acids, and produce reactive oxygen species

what are contained in lysosomal granules?

pro inflammatory cytokines

what do macrophages release?

initiation of the pro inflammatory pathway

what is NF-kB important for?

neutrophils and eosinophils

what are the first responders in phaogcytosis?

antigen presenting cell

what are macrophages and dendritic cells important for?

peptides derived from endogenous sources

what do MHC class I molecules present?

peptides generated fro antigens acquired exogenously

what do MHC class II molecules present?