IMM250 STUDY EXAM QUESTIONS
WITH ALL CORRECT ANSWERS
What are cytoplasmic PRRs? - Answer- They recognize MAMPs that are inside the cell,
includes Nod-like receptors (NLR) and Rig-I-like receptors (RLR)
Why do mucosal epithelial cells have low TLR expression? - Answer- For tolerance of
epithelium to normal microbiota?
What PRRs are prsent in epithelial cells? - Answer- Only the cytoplasmic NLRs and
RLRs are present.
What do NLRP receptors recognize? - Answer- DAMPs such as K+ and ROS. They are
intracellular danger detectors
What happens when NLRPs are activated? - Answer- Do not activate NFkappaB, these
proteins form the inflammasome that processes pro-forms of cytokines to active
molecules. IE activates CASPASE 1 into active form which then goes onto cleave pro-
IL-1beta into an active cytokine
What are RLRs? - Answer- Rig-I-like receptors which are activated by nucleic acid,
CARD and MAVS then act as adaptors to propagate the signal to produce NFkB and
interferons
Why is Pyrin domain necessary for NLRP3? - Answer- Necessary for binding of NLRP3
to an ASC adaptor. NOD via Pyrin binds to ASC resulting in a conformation change
leading to Caspase-1 activation
What is IL-1B? - Answer- Active cytokine cleaved by active Caspase-1
What are cytokines? - Answer- A category of signal molecule that are used extensively
in cellular communication; cytokines generally enhance the ability of our cells to get rid
of an invading pathogen
What type of cells are brought to the site of infection? - Answer- Leukocytes
How do they get past the endothelial cells? - Answer- Cytokine activated endothelial
cells express adhesion moelcules (tethering and rolling). It is mediated by selectins.
, What is the process of exiting and traveling to the infected site called? - Answer-
Migration and diapedesis
What is produced from pluripotent hemopoietic stem cells? - Answer- Common
lymphoid progenitors and myeloid progenitors
What is produced by common lymphoid progenitors? - Answer- T and B lymphocytes
and NK cells
What is produced by myeloid progenitors? - Answer- Mast cells, basophils, eosinophils,
neutrophils and dendritic cells
What cells are categorized as granular cells? - Answer- Neutrophils, eosinophils,
basophils and mast cells
What are monocytes/macrophages? - Answer- Monocyte in blood, when reaching tissue
they are called macrophages and become flat. Their job is to eat pathogens and help
present chewed up pieces of pathogen to T cells
What is the mechanism by which phagocytes kill pathogens? - Answer- Acidification
(3.5-4 pH), bacteriostatic or bactericidal. ROS, toxic nitrogen oxides, antimicrobial
peptides (defensins), enzymes, competitors (Lactoferrin binds Fe)
What are dendritic cells? - Answer- Resident cells in mucosal tissue, expert APCs.
Difference is that dendritic is localized and hang around tissue whereas macrophages
circulate in blood stream
What are neutrophils? - Answer- Phagocytic neutrophils respond to interleukin-8.
Migrate from blood to tissue and usually is first. Cytoplasm full of granules with toxin
products to kill pathogens. Neutrophils die after taking up microorganisms and cause
alot of collateral damage. Produces neutrophil extracellular traps of DNA to trap
microorganism --> Produces lots of DAMPs
What are basophils? - Answer- Least common, lots of toxic substances in granules and
produce alot of histamine -->allergic response. Also antiparasitic (?)
What are eosinophils? - Answer- Granulocytes, deal with parasitic infection and allergy.
Not normally circulating like others.
What are mast cells? - Answer- Parasitic and allergy, produces alot of histamine also
What are granulocytes? - Answer- Characterized by multi-lobular nuclei and cytoplasm
filled with granules (neutrophils, eosinophils, basophils)
What are the effects of granulated substances by mast cells? - Answer- Vasodilation,
increased vasopermeability, contraction of smooth muscle, etc
WITH ALL CORRECT ANSWERS
What are cytoplasmic PRRs? - Answer- They recognize MAMPs that are inside the cell,
includes Nod-like receptors (NLR) and Rig-I-like receptors (RLR)
Why do mucosal epithelial cells have low TLR expression? - Answer- For tolerance of
epithelium to normal microbiota?
What PRRs are prsent in epithelial cells? - Answer- Only the cytoplasmic NLRs and
RLRs are present.
What do NLRP receptors recognize? - Answer- DAMPs such as K+ and ROS. They are
intracellular danger detectors
What happens when NLRPs are activated? - Answer- Do not activate NFkappaB, these
proteins form the inflammasome that processes pro-forms of cytokines to active
molecules. IE activates CASPASE 1 into active form which then goes onto cleave pro-
IL-1beta into an active cytokine
What are RLRs? - Answer- Rig-I-like receptors which are activated by nucleic acid,
CARD and MAVS then act as adaptors to propagate the signal to produce NFkB and
interferons
Why is Pyrin domain necessary for NLRP3? - Answer- Necessary for binding of NLRP3
to an ASC adaptor. NOD via Pyrin binds to ASC resulting in a conformation change
leading to Caspase-1 activation
What is IL-1B? - Answer- Active cytokine cleaved by active Caspase-1
What are cytokines? - Answer- A category of signal molecule that are used extensively
in cellular communication; cytokines generally enhance the ability of our cells to get rid
of an invading pathogen
What type of cells are brought to the site of infection? - Answer- Leukocytes
How do they get past the endothelial cells? - Answer- Cytokine activated endothelial
cells express adhesion moelcules (tethering and rolling). It is mediated by selectins.
, What is the process of exiting and traveling to the infected site called? - Answer-
Migration and diapedesis
What is produced from pluripotent hemopoietic stem cells? - Answer- Common
lymphoid progenitors and myeloid progenitors
What is produced by common lymphoid progenitors? - Answer- T and B lymphocytes
and NK cells
What is produced by myeloid progenitors? - Answer- Mast cells, basophils, eosinophils,
neutrophils and dendritic cells
What cells are categorized as granular cells? - Answer- Neutrophils, eosinophils,
basophils and mast cells
What are monocytes/macrophages? - Answer- Monocyte in blood, when reaching tissue
they are called macrophages and become flat. Their job is to eat pathogens and help
present chewed up pieces of pathogen to T cells
What is the mechanism by which phagocytes kill pathogens? - Answer- Acidification
(3.5-4 pH), bacteriostatic or bactericidal. ROS, toxic nitrogen oxides, antimicrobial
peptides (defensins), enzymes, competitors (Lactoferrin binds Fe)
What are dendritic cells? - Answer- Resident cells in mucosal tissue, expert APCs.
Difference is that dendritic is localized and hang around tissue whereas macrophages
circulate in blood stream
What are neutrophils? - Answer- Phagocytic neutrophils respond to interleukin-8.
Migrate from blood to tissue and usually is first. Cytoplasm full of granules with toxin
products to kill pathogens. Neutrophils die after taking up microorganisms and cause
alot of collateral damage. Produces neutrophil extracellular traps of DNA to trap
microorganism --> Produces lots of DAMPs
What are basophils? - Answer- Least common, lots of toxic substances in granules and
produce alot of histamine -->allergic response. Also antiparasitic (?)
What are eosinophils? - Answer- Granulocytes, deal with parasitic infection and allergy.
Not normally circulating like others.
What are mast cells? - Answer- Parasitic and allergy, produces alot of histamine also
What are granulocytes? - Answer- Characterized by multi-lobular nuclei and cytoplasm
filled with granules (neutrophils, eosinophils, basophils)
What are the effects of granulated substances by mast cells? - Answer- Vasodilation,
increased vasopermeability, contraction of smooth muscle, etc
