Deck 26: Molecular Immunology

Question 1

The two-stage thymic selection process for selecting self-tolerant,antigen-reactive T cells results in

A)allelic exclusion.
B)clonal deletion.
C)complementarity-determining regions.
D)somatic hypermutation.

Answer 1

B

Question 2

The main bonds present in the C domain of antigen-binding proteins are

A)hydrogen bonds.
B)intrachain disulfide bonds.
C)ionic bonds.
D)van der Waals forces.

Answer 2

B

Question 3

Which of the following contribute to the limitless diversity generated from a relatively fixed number of immunoglobulin genes?

A)hypermutation
B)random heavy and light chain reassortment
C)somatic recombination
D)hypermutation,random heavy and light chain reassortment,and somatic recombination.

Answer 3

D

Question 4

Which of the following biomolecules interact with toll-like receptors (TLRs)?

A)bacterial LPS
B)immunoglobulins
C)major histocompatibility complex proteins
D)none of these

Question 5

Antibodies consist of four polypeptides,________ heavy chains,and ________ light chains.

A)one / three
B)two / two
C)three / one
D)four / four

Question 6

Class II MHC proteins have grooves with

A)closed ends.
B)open ends.
C)both open and closed ends.
D)neither open nor closed ends.

Question 7

Which of the following are proteins that interact directly with antigens during the adaptive immune response?

A)immunoglobins
B)major histocompatibility complex
C)T cell receptors
D)all of these

Question 8

An epitope is ________ amino acids long.

A)3-5
B)10-15
C)50-60
D)700

Question 9

More than ________ % of all T cell precursors that enter the thymus do NOT survive the selection process.

A)15
B)25
C)45
D)95

Question 10

The C domain of antigen-binding proteins functions to

A)attach the antigen-binding domain to the cytoplasmic membrane.
B)bind to the cytoplasmic membrane of foreign cells.
C)complex multiple antigen-binding proteins together.
D)bind to epitopes.

Question 11

Each of the V domains in immunoglobulins has ________ complementarity-determining regions.

A)one
B)two
C)three
D)four

Question 12

Which of the following is/are MHC class I genes?

A)HLA-A
B)HLA-B
C)HLA-C
D)HLA-A,HLA-B,and HLA-C

Question 13

TCRs associate with the adapter molecule

A)CD3.
B)CD28.
C)Igα.
D)Igβ.

Question 14

Assuming that each heavy and light chain has an equal chance to be expressed in each cell,approximately how many possible antibodies can be expressed?

A)192
B)1,920
C)19,200
D)1,920,000

Question 15

Somatic hypermutation occurs only in the ________ regions of rearranged heavy and light chains.

A)D
B)HV
C)J
D)V

Question 16

An individual usually expresses ________ structurally distinct allele(s)that encode class I MHC proteins.

A)one
B)two
C)four
D)six

Question 17

Pattern recognition receptors (PRRs)are found on which of the following cells?

A)macrophages
B)bacteria
C)neutrophils
D)macrophages and neutrophils

Question 18

C-reactive protein is a

A)pathogen-associated molecular pattern (PAMP).
B)homotrimeric adaptor protein.
C)lipoprotein.
D)pattern recognition receptor (PRR).

Question 19

Clonal anergy is a state of

A)antibody production.
B)high energy.
C)unresponsiveness.
D)high energy and antibody production.

Question 20

Interaction of a pathogen-associated molecular pattern (PAMP)with a pattern recognition receptor (PRR)results in

A)formation of transmembrane pores that cause cell lysis.
B)transmembrane signal transduction that initiates transcription of genes involved in phagocytosis,inflammation,and pathogen killing.
C)molecular activation of the adaptive immune system.
D)a superantigen reaction that can cause septic shock.

Question 21

Which of the following is involved in B cell selection and tolerance?

A)clonal anergy
B)clonal deletion
C)clonal anergy and deletion
D)allelic exclusion

Question 22

The ________ and ________ domains of the class II MHC protein interact to form a peptide-binding site.

A)B / T
B)light / heavy
C)C / V
D)α1 / β1

Question 23

Chemokines are a group of small proteins that

A)attract T cells to sites of injury.
B)function as chemoattractants for phagocytes and lymphocytes.
C)potentiate specific immune responses.
D)attract T cells,phagocytes,and lymphocytes,as well as potentiate specific immune responses.

Question 24

Interaction of a PAMP with a TLR triggers transmembrane signal transduction and subsequent

A)clonal expansion.
B)antibody production.
C)complement protein activation.
D)phagocytosis and inflammation.

Question 25

The complete second signal for B cell activation requires which of the following interactions?

A)CD40-CK40L interaction
B)cytokine-cytokine receptor interaction
C)TH-B cell interaction
D)All of these are necessary.

Question 26

The occurrence of multiple alleles at a specific locus is called

A)signal transduction.
B)the variable domain.
C)polymorphism.
D)allelic exclusion.

Question 27

Communication between cells of the immune system is accomplished in many cases through

A)allelic exclusion.
B)clonal deletion.
C)cytokines.
D)allelic exclusion,clonal deletion,and cytokines.

Question 28

The peptides bound by a single MHC protein share a common

A)C domain.
B)peptide motif.
C)V domain.
D)nucleotide sequence.

Question 29

The PAMP recognized by mannose-binding lectin (MBL)is the sugar mannose,found as a repeating subunit in

A)human mucus.
B)lymphocyte receptors.
C)bacterial and fungal polysaccharides.
D)bacterial peptidoglycan.

Question 30

Which of the following roles do B cells play?

A)antigen presentation
B)antigen processing
C)antigen uptake
D)antigen presentation,processing,and uptake

Question 31

Immunoglobulins and TCRs associate with adaptor molecules that have

A)a C domain.
B)immune-based tyrosine-activation motifs (ITAMs).
C)pathogen recognition receptors.
D)toll-like receptors.

Question 32

The ________ is a highly conserved amino acid sequence found in immunoglobulin,TCR,and MHC proteins.

A)heavy chain
B)V domain
C)C domain
D)light chain

Question 33

Which of the following cytokines acts to stimulate natural killer cells and induce naïve T cells to differentiate to TH1 cells?

A)IL-1β
B)IL-6
C)IL-12
D)TNF-α

Question 34

Which of the following stimulate macrophage differentiation and activation?

A)granulocyte-monocyte colony stimulating factor
B)interferon gamma
C)tumor necrosis factor-alpha
D)granulocyte-monocyte colony stimulating factor,interferon gamma,and tumor necrosis factor-alpha

Question 35

The major histocompatibility complex is also called the

A)human leukocyte antigen (HLA).
B)T cell receptor.
C)toll-like receptor complex.
D)T cell receptor or toll-like receptor.

Question 36

Chemokines produced by activated macrophages include

A)CXL8.
B)CCL2.
C)MCP-1.
D)CXL8,CCL2,and MCP-1.

Question 37

Which of the following is a likely target for a toll-like receptor (TLR)?

A)tumor necrosis factor
B)interleukin IV
C)flagellin
D)insulin

Question 38

Signal transduction pathways initiate activation of transcription after specific

A)TH cell death.
B)ligand-receptor binding on the cell surface.
C)cytokines diffuse across the cytoplasmic membrane.
D)antigen-antibody binding.

Question 39

Which of the following are soluble mediators and activators for T lymphocytes and B cells?

A)IL-2
B)IL-4
C)IL-5
D)IL-2,IL-4,and IL-5

Question 40

The chemokine CCL2

A)attracts basophils,eosinophils,monocytes,and dendritic cells.
B)stimulates production of inflammatory mediators.
C)organizes an antigen specific immune response.
D)attracts basophils,eosinophils,monocytes,and dendritic cells; stimulates production of inflammatory mediators; and organizes an antigen specific immune response.

Question 41

The antigen-binding site of an antibody accommodates a small portion of the antigen called a(n)

A)lipopolysaccharide.
B)epitope.
C)peptide motif.
D)pathogen associated molecular pattern (PAMP).

Question 42

Cytokines produced by lymphocytes are often called

A)interleukins.
B)pathogen recognition receptors.
C)chemokines.
D)epitopes.

Question 43

The failure to develop tolerance may result in dangerous reactions to self-antigens,a condition called

A)type I hypersensitivity.
B)immunotolerance.
C)autoimmunity.
D)immunodeficiency.

Question 44

All TLR can react with only one specific PAMP.

Question 45

________ ensures that each B cell produces only one immunoglobulin.

A)Self-activation
B)Allelic exclusion
C)MHC interaction
D)Clonal deletion

Question 46

Some activated B cells are transformed into ________ cells that secrete antibodies,and others remain as ________ cells.

A)plasma / memory B
B)lymphocytes / memory B
C)immunoglobulin / plasma
D)immunoglobulin / TH

Question 47

TCRs are found exclusively on T cells.

Question 48

Immunoglobulin,TCR,and MHC proteins share structural features and have evolved by duplication and selection of primordial antigen receptors.

Question 49

B cells react with antigens through TCR antigen receptors.

Question 50

The cytoplasmic domains of immunoglobulins and TCRs have cytoplasmic tyrosines that can be phosphorylated.

Question 51

Amino acid variability is especially apparent in several ________ in the V domains of different immunoglobulins.

A)heavy chains
B)complementarity-determining regions (CDR)
C)peptide motifs
D)epitopes

Question 52

All proinflammatory cytokines EXCEPT ________ induce fever at the systemic level.

A)IL-4
B)IL-12
C)IL-6
D)IL-17

Question 53

Immunoglobins associate with the adapter molecules Igα and Igβ.

Question 54

In B cell selection and tolerance,if no signal is generated from ________ cells,the B cells remain unresponsive.

A)TC
B)TH
C)B₇
D)CD₂₈

Question 55

Adapter molecules associate covalently with their respective antigen receptors in the membrane.

Question 56

Mannose on mammalian cells is inaccessible to mannose-binding lectin.

Question 57

The invariant amino acids in each peptide motif bound by MHC proteins are called

A)anchor residues.
B)MHC peptides.
C)antigen-binding immunoglobulins.
D)TCR peptides.

Question 58

When two allelic variants are expressed equally,they are said to be

A)exclusive.
B)uncommitted.
C)repressed.
D)codominant.

Question 59

Antigen receptors can directly connect to signal transduction pathways because immunoglobulins and TCRs have very small cytoplasmic domains.

Question 60

The mechanism by which antigen-reactive cells respond to foreign antigens while ignoring self-antigens is called clonal

A)selection.
B)deletion.
C)anergy.
D)expansion.

Question 61

A patient is waiting for a kidney transplant.In order for the transplant to be successful,the donated kidney (the graft)must "match" with the recipient.What has to "match" between the donor and the recipient? Why is matching tissue more difficult than matching blood types?

Question 62

T cells undergo immune selection FOR potential antigen-reactive cells and selection AGAINST those cells that react strongly with self-antigens.

Question 63

Describe the signal transduction pathway that is activated when LPS binds to TLR-4.

Question 64

Somatic hypermutation mechanisms generate TCR diversity.

Question 65

The human leukocyte antigen spans about 4Mbp on human chromosome 6.

Question 66

Selection against self-reactive clones results in the development of tolerance.

Question 67

Antibodies are insoluble proteins.

Question 68

Class I MHC proteins have grooves with open ends.

Question 69

What role does the C domain play in cell surface proteins that interact directly with antigens?

Question 70

The clonal selection theory states that each antigen-reactive B cell or T cell has a cell surface receptor for a single antigen epitope.

Question 71

In somatic hypermutation,the mutation of immunoglobulin genes occurs at much higher rates than the mutation rates observed in other genes.

Question 72

Some immature B cells are reactive to self-antigens but do not become activated even when exposed to high concentrations of self-antigens.

Question 73

Each immunoglobulin or TCR interacts with a single antigen,but MHC proteins can interact with more than one antigen.

Question 74

The embedded peptides in MHC proteins are normally derived from breakdown products of cell metabolism.

Question 75

In antigen binding,MHC protein binds to the T cell epitope,whereas the TCR binds the MHC motif.

Question 76

In clonal selection,cells that have not interacted with antigen do not proliferate.

Question 77

What is the effect of an antigen binding a membrane protein on adapter molecules?

Question 78

Affinity maturation is one of the factors responsible for a stronger secondary immune response.

Question 79

The arrangement of Class II MHC proteins in pairs or trimers enhances their stability.

Question 80

After a B cell is activated,it no longer needs T cell interactions or cytokines to make antibody.