Exam I Flashcards
A neutrophil is identified by the expression of ________ on their cell surface.
CD66
What type of cell contains azurophilic granules and secondary granules?
Neutrophils
Which type of cells is identified by the expression of CD14, CD11b, or F4/80?
Macrophages
Which type of signals induce chemotaxis of macrophages towards the site of microbe entry?
SOS (danger) signals such as peptides, complement proteins, cytokines, and N-formyl-methionine
What type of cells are cytokines released from?
Macrophages
What is the function of interferons? What kind of cell are they release from?
Inhibit infection and replication of viruses
NK cells
What is responsible for increasing the temperature during inflammation and inducing acute phase proteins?
Interleukin 1
________ receptors enable macrophages to bind to microorganisms.
Fc
What has to occur before the Fc end on an antibody is exposed to macrophages?
An antibody must bind to an antigen.
The name of the most important complement system receptor that is found on phagocytes is the ________ receptor.
C3b
What are the two killing pathways used by macrophages, neutrophils and monocytes during an innate immune response?
Oxidative Pathway
Non-Oxidative Pathway
The non-oxidative pathway is dependent on __________, while the oxidative pathway is dependent on ____________.
lysosomal toxic substances;
generation of reactive oxygen species (ROS) and reactive nitrogen speies( RNS)
What substance sequesters iron thereby inhibiting bacterial growth during phagocytosis?
Lactoferrin
Which cytokine is responsible for the production of NO, which is toxic to microorganisms in the vicinity of phagocytes?
TNFalpha
What do the following have in common? TLR NLR RLR CLR PRGP
These are the five classes of pattern like receptors which recognize PAMPs on microbes invading body.
What type of pattern like receptors is located on the host cell membrane as well as inside the host cell?
Toll like receptors
What are some important TLR? Why
All recognize viruses TLR 3 TLR 7 TLR 8 TLR 9
What is the end results of signaling of Toll like receptors?
Production of proinflammatory cytokines
What are the PRRs called that detect viral RNA and are expressed in the cytoplasm of innate immune cells?
Rig Like Receptors
What type of pattern recognition receptors are expressed on the skin , bone marrow, and intestines of pigs?
PGRP receptors
If serum protein levels change during infections, what is this process called?
Acute Phase Response
Complement system proteins and C-reactive proteins are serum proteins that change in level during infection. What is another name for these proteins? Where are they synthesized?
Acute Phase Response Proteins
Liver
How are acute phase response proteins synthesized?
Proinflammatory cytokines like TNF alpha, IL-1, and IL-6 induced synthesis by acting on hepatocytes in the liver
B cells recognize ________ antigens while T cells recognize _________ antigens.
Extracellular
Intracellular
What does Th and Tc stand for?
Th= Helper T lymphocytes Tc= Cytotoxic T lymphocytes
What makes natural killer cells very different from macrophages
They do not possess receptors that are generated through gene segment rearrangement
These cells originate in the bone marrow, migrate only when there is an inflammatory reaction, and can be found in the blood, spleen, and liver.
NK Cells
The cytokine IFNy is secreted by _________ and is important in the regulation of the _________ response
NK cells
Immune
What is another name for NK cells?
Large Granular Lymphocytes
How do NK cells become lymphokine activated killer cells?
Activated by the cytokines IL-2 and IFNy in vitro
What proteins are highly expressed on highly stressed cells that enable NK cells to recognize them?
MICA
MICB
RAE-1
H60
Activating signals induce the _________ of NK cell target cells while inhibiting signals induce the _________ of these cells.
Killing
Saving
How are normal, healthy cells saved from NK cells?
Their activating signals are blocked by inhibitory signals
If a cell is normal, it will express normal __________ molecules.
MHC class I
What are the NK cell receptors called that recognize MHC class I in humans, pigs, cattle, cats, and dogs?
KIRS
KLR are NK receptors that recognize MHC class I in which species?
Horses
Mice
Rats
What are some important activating receptors on NK cells that bind with ligands on target cells?
NKp46
CD16
NKG2D (KLR)
Is CD94/NKG2A an inhibitory or activating NK receptor?
Inhibitory
WHich NK cell receptor recognizes stress proteins like MICA and MICB?
NKG2D
T/F NK cells can recognize target cells through an antibody dependent pathway using CD20.
False: CD16 (Fc receptor)
T/F NK cells can activate macrophages.
True
Describe the relationship between CD16 and NK cells. What is the name for this phenomenon?
NK cells bind to antibodies that had previously binded on the antigen of an infected cell through CD16.
ADCC (antibody-dependent-cellular-cytotoxicity)
What is the main mechanism by which NK cells kill target cells? What is the key part of this mechanism that allows killing?
Perforin-dependent mechanism
Perforin is released from granules which creates a lesion in the target tissue creating a channel where protease and granzymes enter to kill cell.
What are the signs of acute inflammation in the correct order?
Calor: Heat Rubor: Redness Tumor: Swelling Dolor: Pain Functio laesa: Loss of function
What are the three vascular responses during inflammation?
I: Vasoconstriction
II: Vasodilation (active)
III: Vasodilation (passive)
When leukocytes (granulocytes and monocytes) move into the area of injury during inflammation, what is this called?
Cellular Inflammatory Response
What are the four steps involved during the cellular inflammatory response?
- Chemotaxis
- Rolling
- Migration
- Phagocytosis
What type of molecules are needed in order to leukocytes to migrate out of the vasculature into the injured tissue?
CAMs (cell adhesion molecules)
Selectins, Mucins, Integrins, and Ig superfamilys are all considered ____________.
Cell adhesion molecules
What type of CAM binds to carbohydrate moieties found on mucin CAMs?
Selectins
What are the three important selectins?
Selectin E, L and P
What two CAMS are responsible for the rolling action of leukocytes along the endothelium?
Selectins and Mucins
Integrins on leukocytes are paramount in what step of Leukocyte Extravasation?
Adhesions of Leukocytes to the endothelium
What are some examples of vasoactive amines? What do they do?
Serotonin
Histamine
They cause increase vasodilation and permeability of capillaries during an inflammatory response.
What substance contributes to vasodilation, capillary permeability, pain and fever during inflammation?
Prostoglandins
What is the purpose of C3a and C5a?
Complement proteins that increase vascular permeability during inflammation.
What stimulates the release of acute phase proteins such as C-reactive proteins during inflammation?
IL-6
What are leukotrienes and what do they do during the inflammatory response?
Slow reacting substances of anaphylaxis which cause smooth muscle contraction and attract neutrophils to the injured area.
Name this substance: is generated from lipids complexes stored in cell membranes, induces platelet aggregation, activates neutrophils, attracts eosinophils, and causes the efflux of plasma proteins (edema).
Platelet activating factor
Bradykinin _________ capillary permeability and also plays a role in _____ during inflammation.
Increases
Pain
During what phase of the vascular response of inflammation would you see calor and rubor?
Phase II: Active Vasodilation
A patient is currently experiencing a Phase III vascular response, what is occurring?
Passive vasodilation with tumor, pain, and impaired function
Integrin…explain this shit.
It is a CAM which consists of an alpha and beta chain forming the binding site for another CAM called Ig superfamily.
What are four phases of leukocyte extravasation?
Rolling
Activation
Adhesion
Transendothelial migration
Inflammation is terminated by the up-regulation of molecules such as ____________ and _____________. In addition to the production of anti-inflammatory ____________ from granulocytes.
Interleukin I receptor antagonist
Soluble tumor necrosis factor receptor
Lipotoxins
During what phase of leukocyte extravasation do mucin CAMs on leukocytes bind to selectin E and P on entholiatlal cells?
Phase I: Rolling
What occurs during the Phase II of leukocyte extravasation?
Cytokine and chemokine secretion by endothelial cells increases causing activation of leukocytes.
During what phase of leukocyte extravasation do leukocytes squeeze through the endothelium with the help of homotypic binding of platelet endothelial cell adhesion molecule 1?
Phase 4: Diapedesis (transendothelial migration)
The binding of C1q to the surface of a pathogen (antibody:antigen) starts which complement pathway?
Classical
How is the Lectin complement pathway activated?
Binding of carbohydrate-binding proteins to carbohydrates on surface of the pathogen
Give two examples of carbohydrate-binding proteins.
Mannose-binding lectin
Ficolins
The binding of spontaneously derived plasma C3b to pathogen surfaces activates which complement pathway?
Alternative
What is the main effector molecule of the complement system that acts like opsonins?
C3b
What is C3a’s role in the complement pathway?
Mediates inflammation
How is the membrane attack complex activated?
In the classical and lectin pathway, the C5b and the C5 convertase (C4b2a3b) generate the Mac formation. In the alternative pathway, C5b and the C5 convertase (C3bBb3b) do the same.
What are the three main outcomes of the C3a and C5a proteins in the complement pathway?
Tissue Inflammation
Endothelial activation
Chemotaxis
What is protolectin (CD59)?
It is a complement control protein responsible for preventing C9 from binding to the C5b678 complex inhibiting MAC formation.
What protein is responsible for accelerating the decay of C3 convertase and contributing to the inhibition of complement in the alternative pathway?
Decay-accelerating factor (CD55)
What binds to C3b in the alternative pathway in order to accelerate it’s decay?
Factor H and I
What is the role of the C1 inhibitor protein?
It works within the classical and lectin complement pathways to inactivate C1r, C1s, and MASPs
How does the complement system activate the adaptive immune system?
Due to opsonization, APC’s like dendritic cells are able to uptake microbes and B cells respond faster to the coated microbes.
What are considered the most potent activators of the complement system?
IgM and IgG due to the fact that when they bind to an antigen, the Fc portion can bind to C1.
In the alternative pathway, was is the C3 convertase stabilized by?
Factor P
What cell can present antigen to naive CD4 T cells and CD8 T cells?
Dendritic Cells
What kind of T cells do macrophages present antigen to?
Differentiated CD4 T cells during the effector phase of cell-mediated immunity
Would B cells or dendritic cells present antigen to helper CD4 T cells during the humoral cell response?
B cells
What are the two most important functions of APCs?
- Convert protein antigen to peptides and display peptide-MHC complexes to T Cells
- Co-stimulate T cells
If an antigen is present in the acidic vesicular compartment of APC’s, what type of antigen presentation is this? What type of T cells will recognize these antigens?
MHC class II restricted CD4
Where would peptides be associated with MHC class II molecules during the antigen processing/presentation of pathway of endocytosed antigens?
In the endocytotic vesicles
Where are peptides transported to that also serves as the location for the assembly of the peptide-MHC class I complex during the processing of cytosolic antigens?
The endoplasmic reticulum
T/F B cell receptors interact with MHC molecules.
False
What would happen if the CD3 complex did not interact with a T cell receptor?
The TCR would not be able to be expressed on the T cell.
Each T cell has a TCR of only ________ specificity.
One
A alphabeta TCR is MHC ___________ while a gammadelta recognizes antigen in a _________ manner.
Dependent
Independent