L5-Exam 2 Flashcards
List the three professional phagocytes:
List the two non-professional phagocytes:
Professional Phagocytes:
1.Neutrophils, 2.Monophils/Macrophages
3.Dendritic Cells
Non-Professional Phagocytes:
1.Basophils
2.Eosinophils
True or False: Professional phagocytes originate from myeloid lineages
True
What is the first leukocyte to the site of an infection?
Neutrophils
True or False: Neutrophils cannot renew their lysosomes and can kill intra or extracellularly
True
Where are monocytes found? Macrophages?
Monocytes - blood
Macrophages - tissue
True or False: Monocytes/Macrophages/Dendritic cells can present antigens to T cells
True
Where are dendritic cells predominately found?
Lung, skin, GI (potential sites of pathogen entry)
True or False: Dendritic cells actively induce generation of ROS/toxic products that induce local inflammation
False - Dendritic cells do NOT actively induce generation of ROS/toxic products that induce local inflammation
Monocytes/Dendritic cells arrive and are activated ___
Neutrophils arrive and are activated ____
Monocytes/Dendritic cells arrive and are activated SLOWLY
Neutrophils arrive and are activated QUICKLY
Which have a longer life span: neutrophils vs. monocytes/dendritic cells?
Monocytes/Macrophages/Dendritic Cells
_____: directed movement of cells through a chemical gradient - in response to receptors found
Chemotaxis
Which endogenous factors encourage chemotaxis?
1) C5a
2) IL-1 and TNF-a
3) Chemokines (IL-8*)
4) LTB4
5) Fibrinopeptide B and Kinin
What type of molecules are involved in both pinocytosis and receptor mediated endocytosis?
Soluble molecules
___: process where cells ingest and destroy insoluble particles
Phagocytosis
____: non-specific invatigations in cell membrane with coincidental internalization of accompanying extracellular molecules
Pinocytosis
Phagocytosis is initiated when several types of ___ are bound by pathogens. Provide 4 examples.
receptors
1) PRR/TLR
2) Fc - recognize bottom 1/2 of Ab
3) Complement receptors
What type of receptors bind to opsonins on the surface of microbes?
1) Complement Receptors
2) Fc Receptors
____: molecules that, when bound to the surface of microbes, makes them more attractive to phagocytic cells
Opsonins (C3b and IgG)
True or False: When a microbe is covered with either C3b or IgG, receptors for C3b or IgG can tightly grab onto the microbe and ingest it
True
Some organisms produce a hydrophilic ____ that make it hard for phagocytes to surround and phagocytose these organisms
hydrophilic
True or False: Production of capsules enable a pathogenic organisms to more readily cause disease
True
Once a microorganism is engulfed by a phagocyte, a ___ is formed
phagosome (phagocytic vesicle)
What are the three effects that arise due to the formation of the phagosome?
- increase in cell size
- become more phagocytic
- production of destructive molecules
Once the phagosome fuses with lysosomes, a ___ is formed
phagolysosome
Where does the Oxidative Burst chemical reaction occur? Products of the reaction?
Phagolysosome
(O2- and hypochlorite)
Note: Oxidative Burst requires oxygen
True or False: superoxide (O2-), H2O2, OH- and OCl- are products of the oxidative burst and have potent anti-microbial activities
True
A defect in what enzyme leads to Chronic Granulomatous Disease?
Myeloperoxidase
True or False: If one has a defect in myeloperoxidase, neutrophils can phagocytose the pathogen but not intracellularly kill it
True
How is inducible NO Synthase induced?
Cytokines (TNF-a and INF-gamma)
What is the role of iNOS?
Modifies arginine and ultimately makes NO
Three roles of NO?
1) Inhibits Fe/sulfur-dependent enzymes
2) Damages DNA
3) Oxidizes membrane lipids
Where are Lysozymes, Lactoferrin, and Defensins located?
Within phagolysosome
___: attack bacterial cell wall
____: chelates iron (needed for microbial metabolism)
____: disrupt membrane function, induce osmotic lysis
Lysozymes
Lactoferrin
Defensins
What is the function of secreting effector molecules?
Alert and activate the rest of the immune system
Chemocytes recruit ____
Cytokines activate ____ cells
NO can be ____
Chemocytes recruit additional cells
Cytokines active infiltrating cells
NO can be secreted
True or False: Neutrophils do not require significant stimulus to phagocytose and kill, but monocytes/macrophages/dendritic cells do
True
What are three stimuli that enhance neutrophil activation?
1) Stimulation of PRR
2) Complement - increase ox burst
3) Cytokines
What are three mechanisms to activate monocytes/macrophages/dendritic cells?
1) Stimulation of PRR
2) Engage complement receptors / Fc receptors
3) Cytokines !! (INF-gamma)
Which cytokine can impact monocyte differentiation into macrophages AND increase the ability of macrophages/dendrites to present antigen?
INF-gamma
What happens after pathogen is phagocytose and destroyed?
- Nucleic acids and amino acids are re-used
- Peptides broken down into peptide fragments that are “presented” to T lymphocytes to activate T cells (macrophages/dendritic cells) via: antigen presentation
