Deck 30: Molecular Immunology

Question 1

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

A) cytokines with cytokine receptor
B) CD40- CK40L
C) T_H- B cell
D) all of the above

Answer 1

D

Question 2

Class II MHC proteins have groves with

A) both open and closed ends.
B) open ends.
C) closed ends.
D) none of the above.

Answer 2

B

Question 3

TCRs associate with the adapter molecule

A) CD3.
B) Iga.
C) Igfi.
D) CD28.

Answer 3

A

Question 4

An epitope is amino acids long.

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

Question 5

Which of the following roles do B cells play?

A) antigen presentation
B) antigen uptake
C) antigen processing
D) all of the above

Question 6

Clonal anergy is a state of

A) unresponsiveness.
B) high energy.
C) antibody production.
D) all of the above.

Question 7

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

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

Question 8

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

A) random heavy and light chain reassortment
B) hypermutation
C) somatic recombination
D) all of the above

Question 9

Which of the following proteins interact with TLR- 4?

A) heat shock proteins
B) bacterial LPS
C) both LPS and heat shock proteins
D) none of the above

Question 10

Which of the following stimulate macrophage differentiation and activation?

A) tumor necrosis factor- alpha
B) interferon gamma
C) granulocyte- monocyte colony stimulating factor
D) all of the above

Question 11

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

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

Question 12

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

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

Question 13

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

A) HLA- C
B) HLA- A
C) HLA- B
D) all of the above

Question 14

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

A) clonal anergy and deletion
B) clonal deletion
C) clonal anergy
D) none of the above

Question 15

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

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

Question 16

Chemokines are a group of small proteins that

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

Question 17

C- reactive protein is a(n)

A) acute phase protein.
B) type of PAMP.
C) lipoprotein.
D) homotrimeric adaptor protein.

Question 18

PRRs are found on which of the following cells?

A) monocytes
B) macrophages
C) neutrophils
D) all of the above

Question 19

TLR- 4 consists of distinct protein domains.

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

Question 20

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

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

Question 21

Signal transduction pathways initiate activation of transcription through binding on the cell surface.

Question 22

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

Question 23

Intercellular communication in the immune system is accomplished in many cases through

A) cytokines.
B) clonal deletion.
C) allelic exclusion.
D) all of the above.

Question 24

Interaction of a PAMP with a TLR triggers transmembrane .

Question 25

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

Question 26

The chemokine CCL2

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

Question 27

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

A) IL- 12
B) IL- 1fi
C) TNF- a
D) IL- 6

Question 28

An individual usually expresses _ structurally distinct alleles that encode class I MHC proteins.

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

Question 29

The C domain of antigen- binding proteins has approximately amino acids.

A) 400
B) 300
C) 100
D) 200

Question 30

Chemokines produced by activated macrophages include

A) CXL8.
B) MCP- 1.
C) CCL2.
D) all of the above.

Question 31

Cytokines produced by lymphocytes are often called _ or _.

Question 32

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

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

Question 33

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

Question 34

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

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

Question 35

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

Question 36

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

A) IL- 5
B) IL- 2
C) IL- 4
D) all of the above

Question 37

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 38

The invariant amino acids in each peptide motif bound MHC proteins are _.

Question 39

All proinflammatory cytokines except induce fever at the systemic level.

Question 40

The peptides bound by a single MHC protein share a common .

Question 41

ensures that each B cell produces only one immunoglobulin.

Question 42

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

Question 43

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

Question 44

B cells react with antigens through TCR antigen receptors.

Question 45

The target for TLR- 5 is .

Question 46

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

Question 47

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

Question 48

Antibodies are insoluble proteins.

Question 49

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

Question 50

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

Question 51

The major histocompatibility complex is also called the .

Question 52

The occurrence of multiple alleles at a specific locus is called _ .

Question 53

Immunoglobins associate with the adapter molecules Iga and Igfi.

Question 54

Immunoglobulins and TCRs associate with adaptor molecules that have , because they possess tyrosines that can be phophorylated.

Question 55

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

Question 56

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

Question 57

Class I MHC proteins have groves with open ends.

Question 58

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

Question 59

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 60

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

Question 61

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

Question 62

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

Question 63

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

Question 64

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

Question 65

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

Question 66

Briefly describe the structure of Class I MHC proteins.

Question 67

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

Question 68

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

Question 69

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

Question 70

Somatic hypermutation mechanisms generate TCR diversity.

Question 71

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

Question 72

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

Question 73

Briefly describe positive selection in T cell maturation.

Question 74

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

Question 75

TCRs are found exclusively on T cells.

Question 76

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

Question 77

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

Question 78

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

Question 79

If you were a surgeon about to do an organ transplant, what measures would you take to ensure that the recipient's body does not reject the donor organ?

Question 80

All TLR can react with only one specific PAMP.