Recognition and Response Flashcards
All cells receive and respond to signals, but immune cells must:
A. Interact with pathogens
B. Eliminate pathogens
C. Communicate via signal transduction
D. All of the above
D. All of the above
Receptor-ligand binding occurs through multiple (______) bonds that allow sufficient binding.
A. covalent
B. noncovalent
C. ionic
B. noncovalent
What is the strength and affinity of each ligand-receptor bond?
Strength: weak bond
Affinity: strong affinity
Define affinity.
strength of individual bond
Define avidity. What increases avidity?
Avidity: combined binding strength of multiple interactions
- multivalency increases avidity
What 4 molecular changes does ligand-receptor binding induce?
- conformational change
- dimerization (cluster)
- location on membrane
- covalent modification (phosphorylation)
What 3 intracellular events do receptor alterations induce?
- gene transcription
- enzyme activation (kinases)
- protein location changing
List two common features of immunoglobulins.
- immunoglobulin (Ig) domains
- can be located on the transmembrane, cytosol, or secreted
Pattern Recognition Receptors (PRRs) are expressed by (_____) and recognize (______).
innate immune response; PAMPs/DAMPs
B-cell Receptors (BCRs) are expressed by (______) and recognize/bind to (______) antigens.
B-cells; soluble
T-cell Receptors (TCRs) are expressed by (______). They are specific for (______) derived antigens from antigen-presenting cells on (_____) molecules.
T-cells; peptides; MHC
Cytokine Receptors are expresses by all (______) cells and recognize (______).
immune; cytokines
Chemokine Receptors are expresses by all (______) cells, recognize (______), and have (______) coupled-receptors.
immune; chemokines; G-protein
PRRs are our innate immune response that produce which of the following to educate the adaptive immune response?
A. cytokines/chemokines
B. B-cells/T-cells
C. immunoglobulins/amino acids
A. cytokines/chemokines
How many classes of PRRs are there?
5
The B-cell receptor is structured with two heavy chains and two light chains. Name the fragments and functions.
Light chains = Fab
- antigen binding fragment
- antigen specificity
Heavy chains = Fc
- constant fragment
- antibody effector activity
What are the 5 effector antibodies identified on the Fc region of the heavy chain?
- Ig(α) alpha: 4 binding sites
- Ig (Δ) delta: 2 binding sites
- Ig (ϵ) epsilon: 2 binding sites
- Ig (γ) gamma: 2 binding sites
- Ig (μ) mu: 10 binding sites
Which immunoglobulins (antibody effectors) form a BCR complex?
- Ig(α)
- Ig(β)
How do immunoglobulins (Ig) on BCRs transduce signals?
ITAMS
TCRs have peptide sources from (______) or (______) processed antigens.
A. endogenously; exogenously
B. intracellular; extracellular
C. Both are correct
C. Both are correct
What are the coreceptors for TCRs? Which one contains ITAMs to transmit signals?
Coreceptors:
- CD4 (Thelper, MHC II, exogenous)
- CD8 (Tcytotoxic, MHC I, endogenous)
- CD3 (ITAMs)
- CD28 (activates naive T-cell)
T/F. Cytokines are proteins that communicate in the immune system.
True
What 3 types of extracellular signaling do cytokines mediate?
- Endocrine (insulin)
- secreted by signaling cells
- affect DISTANT receptor-expressing target cells - Paracrine (neurotransmitters)
- affect only NEARBY receptor-expressing target cells - Autocrine (growth factors)
- cells respond to signals they secrete
Describe this property of cytokines/chemokines.
- induces different biological effects dependent on target cells
Describe this property of cytokines/chemokines.
- mediates similar effects on target cell
Describe this property of cytokines/chemokines.
- combines two cytokine activities
Describe this property of cytokines/chemokines.
- effect inhibits cytokines effect by another’s action
Describe this property of cytokines/chemokines.
- effect of one cytokine on target cell produces additional cytokines
Interleukin-1 (IL-1) promotes….
- local inflammation
- fever
- stimulates neutrophil production
Interleukin-2 (IL-2) promotes….
- lymphocyte (T and B)
- proliferation
Interleukin-4 (IL-4) promotes….
- Th2 cell differentiation
- IgE class switching
- α-parasites
- allergies
Interleukin-5 (IL-5) promotes….
- eosinophil production
- α-parasites
- allergies
Interleukin-6 (IL-6) promotes….
- proinflammatory
- induces inflammation
- fever
Interleukin-12 (IL-12) promotes….
- Th1 cell differentiation
- IFN-α production
- enhances CTL activity
Which Type I interferons (IFNs) have antiviral effects?
IFN-α
IFN-β
Which type of interferon is IFN-γ?
A. Type I
B. Type II
C. Type III
B. Type II
What is the function of IFN-γ?
- Th1 cell differentiation
- activates macrophages
Tumor Necrosis Factor (TNF) promotes….
- proinflammation (TNF-α)
- induces cell death, apoptosis (FasL)
Which cytokine family are proinflammatory, expressed on bacteria cells, and inflammation in barrier tissues (skin, mucosal)?
A. IL-2
B. IL-12
C. IL-17
D. 1L-6
C. IL-17
What are the 4 proinflammatory ILs?
- IL-1
- IL-6
- TNF-α
- IL-17
What is the function of chemokines?
- induce movement of leukocytes up concentration gradient
List the 3 classes of chemokines.
- CXC
- CC
- CX3C
Which protein-coupled receptors do chemokines act on to promote the movement of immune cells?
A. G protein
B. C protein
C. D protein
A. G protein
T/F. Many receptors can bind to more than one chemokine, but several chemokines cannot bind to more than one receptor.
False.
Many receptors can bind to more than one chemokine, and several chemokines can bind to more than one receptor.
Which coreceptors of T-cells and B-cells are phosphorylated on ITAMs?
T-cells: CD3
B-cells: Ig(α), Ig(β)
What leads to the activation of JAK and STAT transcription factors in cytokine binding?
Dimerization
