review questions Flashcards by Katie Fitzgerald

Which of the following is an example of secondary lymphoid tissue?

a. Liver
b. Spleen
c. Bone Marrow
d. Thymus

B. Spleen

How well did you know this?

Not at all

Perfectly

What is the normal life span of a naive lymphocyte?

a. 5-7 days
b. 1-2 weeks
c. 3-10 hours
d. 1-3 Months

D. 1-3 months

How well did you know this?

Not at all

Perfectly

A cell expressing which of the following will be observed interacting with B cells, macrophages, and dendritic cells?

a. CD4
b. CD34

C. CD8

D. CD25

a. CD4

How well did you know this?

Not at all

Perfectly

What is the purpose of chemokines?

a. stimulation of growth and differentitation of T cells.
b. Cellular homing to certain tissues
c. mediation of antigen presentation
d. stimulation of growth and differentitation of B cells

b. cellular homing to certain tissues

How well did you know this?

Not at all

Perfectly

At what B cell stage would you expect it to be getting ready to interact with a T cell in a lymph node?

a. immature B cell
b. Mature naive B cell
c. Mature activated B cell
d. Pre-B cell

b. Mature Naive B cell

How well did you know this?

Not at all

Perfectly

At what T cell stage would you expect it to be in the infected tissue?

a. Pre- T cell
b. Immature T cell
c. Mature Naive T cell
d. Active T cell

Active T cell

How well did you know this?

Not at all

Perfectly

What is the ligand for CD44?

a. Lipopolysaccharide
b. Flagellin
c. Mannose
d. Hyaluronic acid

d. Hyaluronic Acid

How well did you know this?

Not at all

Perfectly

Chemokine receptors are…

a. G protein coupled receptors
b. Tyrosine kinases
c. Ligand gated ion channels
d. Beta Barrel pores

a. G protein coupled receptors

How well did you know this?

Not at all

Perfectly

Do naive T cells or activated T cells gain the ability to leave the lymph node first?

a. Definitely naive T cells
b. No way man, it’s activated T cells

a. Definitely naive T cells

How well did you know this?

Not at all

Perfectly

Which of the following does not immediately result from TLR binding a ligand?

a. T cell activation
b. ROS production
c. Phagocytosis

a, T cell activation

TLR going to bind to the PAMP which is in “first responders”

How well did you know this?

Not at all

Perfectly

LPS is recognized by what type of TLR?

a. TLR 2/6
b. TLR 1/2
c. TLR 4
d. TLR 5

C TLR 4

How well did you know this?

Not at all

Perfectly

LTA is recognized by what type of TLR?

a. TLR 2/6
b. TLR 1/2
c. TLR 4

D. TLR 5

a. TLR 2/6

TLR 1/2 recognizes lipopeptides which are a characteristic of bacteria in general, but doesn’t differentiate between gram positive and gram negative

How well did you know this?

Not at all

Perfectly

What inflammatory caspase is activated by NLRs?

a, caspase - 1

b. caspase-3
c. caspase-8
d. caspase-9

a. caspase-1

How well did you know this?

Not at all

Perfectly

Mice without SR (scavenger receptors) are….

a. more susceptible to infection by microbial pathogens
b. more susceptible to die via necrosis
c. less susceptible to infection by microbial pathogens
d. able to compensate with NLRs and C-type lectin family receptors

a. more susceptible to infection by microbial pathogens

How well did you know this?

Not at all

Perfectly

C-type lectin receptors recognize which substances?

a. microbial mannonse

b N-acetylglucosamine

c. sialic acid
d. both A and B are correct

e both A and C are correct

d. both A and B are correct

remember C-type lectins recognize microbial mannose, N-acetylglucosamine, and beta0glucan. these are all foreign substances that are not normally found in the human body. sialic acid and galactose are substances that are normally found in the human body so it would be bad if C-type lectins recognized these substances

How well did you know this?

Not at all

Perfectly

Which of the following cytokines most strongly induces fever?

a. IL-1
b. TNF
c. IFN-gamma
d. IL-6

A. IL-1

How well did you know this?

Not at all

Perfectly

Which of the following cytokines most strongly activates endothelial cells to express E-selectins?

a. IL-1
b. TNF
c. IFN-gamma
d. IL-6

B. TNF

How well did you know this?

Not at all

Perfectly

Which of the following cytokines most strongly induces synthesis of acute phase proteins?

a. IL-1
b. TNF
c. IFN-gamma
d. IL-6

d. IL-6

How well did you know this?

Not at all

Perfectly

Which TLR would be the best at recognizing the West Nile Virus in the body?

a. TLR 5
b. TLR 9
c. TLR 2
d. TLR 3

D. TLR3

How well did you know this?

Not at all

Perfectly

Which of the following regions of the antibody contributes to antigen recognition?

a. VL chain
b. CL chain
c. Fc Fragment
d. hinge region

A. VL chain

How well did you know this?

Not at all

Perfectly

Digestion of an Antibody by pepsin yields which of the following?

a. one protein segment that can bind one antigen
b. one protein segment that can bind 2 antigens
c. two protein segments that can bind 1 antigen
d. twp protein segments that can each bind two antigens

b. one protein segment that can bind 2 antigens

How well did you know this?

Not at all

Perfectly

How many constant regions does one IgM heavy chain have?

a. 1
b. 2
c. 3
d. 4

D. 4 because constant region for IgM the part of the stem and one that extends up and to the left

How well did you know this?

Not at all

Perfectly

Describe the affinity and avidity of IgM

a. IgM has high affinity and low avidity
b. IgM has high affinity and low avidity
c. IgM has low affinity and high avidity
d. IgM has low affinity and low avidity

C IgM has a low affinity and high avidity

Doesn’t bind it super well to Ag but have a lot of valence so has a high avidity

How well did you know this?

Not at all

Perfectly

IgM isotype switching to IgA results in the change of what?

a. light chain isotype switching
b. heavy chain isotype switching
c. TCR chain isotype switching
d. IgA isotype switching

B. heavy chain isotype switching

When change changing the heavy not the light

How well did you know this?

Not at all

Perfectly

What cytokine is required for isotype switching to IgG? a. IL-4 b. IL-2 c. TGF-beta d. IFN-gamma

D IFN-gamma

A few weeks after a baby is born, she suddenly becomes sick. The destruction of what Ab, obtained from her mother in the womb, results in inadequate neutralization of the toxin? a. IgG b. IgE c. IgM d. Igd

A. IgG Remember Fcrn is the receptor

You ingested a toxin. What Ab is responsible for neutralizing that toxin in you GI tract? A. IgA B. IgD C. IgE D. IgM

A. IgA J chain and secretory chain

WHat Ab(s) are found on the surface of mature B cells that have not yet been activated? A. IgA b. IgD c. IgE d. IgM e. A and B are correct f. B and C are correct g. B and D are correct

G. B and D are correct IgM and IgD

Class 1 MHCs are encoded by what genes? a. HLA-A, HLA-B, HLA-C b. HLA-DP, HLA-DQ, HLA-DR c. HLA-A, HLA-B, HLA-D d. HLA-DP, HLA-DM, HLA-DQ

a. HLA-A, HLA-B, HLA-C

Class 2 MHCs are found on what cells? a. all nucleated cells b. only professional APCs C. B cells, Dendritic cells, and Macrophages d. Monocytes e. B and C are correct

e. B and C are correct

The CD8 coreceptor recognizes what type of cells? a. cells expressing MHC Class 1 b. cells expressing MHC Class 2 c. Cells expressing Beta-2 microglobulins d. Cell expressing CD3 complexes

a. cells expressing MHC Class 1 technically c is correct too Beta-2 microglobulins are part of MHC class 1

TH1 cells fight what type of infection? a. extracellular infection b. intracellular infection c. helminths infection d. CTL infection

b. intracellular infection ## Footnote There are two types TH1 and TH2 that we talked about but TH1 is intracellular so answer is B TH2 is extracellular TH1 activated macrophages and they are going to eat intracellular cells TH2 is going to make Abs and those fight extracellular

Th2 cells make IL-4. In the presence of IL-4, what Antibody is produced by plasma cells? a. IdA b. IgD C. IgE d. IgM

C. IgE

What are the components of the TCR complex? a. MHC class 1, CD8, linear peptide b. MHC class 2, CD4, linear peptide c. alpha/beta TCR, CD3, and Zeta chains d. delta/gamma TCR, CD40L, and Zeta chains

c. alpha/beta TCR, CD3, and Zeta chains

What are the signaling components of the TCR complex? a. alpha/beta TCR b. CD3 c. Zeta chains d. CD40 e. B and C

e. B and C

Which of the following cell types cannot express Class I MHC? a. T cells b. Hepatocytes c. B cells d. Red blood cels

d. Reb blood cells

You have a cell sample stained to see all CD3+ cells. What do you stain for next in order to identify cells that respond to extracellular pathogens? A. CD4 B. CD8 C. Class I MHC d. Class II MHC

A. CD4 the first stain stained all the T cells

A macrophage phagocytizes a pathogen. It then escapes into the cytoplasm. After Antigen processing, in what MHC will the antigen be expressed? a. Class I b. Class II

A. Class I

Which of the following is not a quality of an activated dendritic cell? a. ability to present antigen to T cells b. expression of Fc and mannose receptors c. expression of costimulatory molecules (B7, ect.) d. Increased expression of MHC molecules

B. expression of Fc and mannose receptors ## Footnote They will express to capture the Ag and once activated won't need because it wants to now activate the T cell

Insulin is an example of what type of receptor? a. nuclear hormone receptor b. non-receptor tyrosine kinase based receptor c. GPCR d. Tyrosine Kinae Receptor (RTK)

d. Tyrosine Kinase Receptor (RTK)

What type of receptor does glucagon utilize? a. nuclear hormone receptor b. non-receptor tyrosine kinase based receptor c. GPCR d. Tyrosine Kinase Receptor (RTK)

c. GPCR (chemokines and PGs also use GPCRs

CD4/CD8 are associated with what family of kinases? a. Src familly b. Syk family c. Tec family d. ZAP-70 family

A. Src family (c-Src, Lyn, Fyn, Lck, Blk) Syk (Sky and Zap-70) Tec (Tec, Btk, Itk)

SH3 domains recognize what characterisitcs of polypeptides? a. phosphotyrosine residues b. proline-rich stretches c. PIP3 and other phosphatidylinositol-derived lipids d. phosphatidylserine residues

b. proline-rich stretches

What recognizes phosphotyrosine residues? a. SH3 domains b. SH2 domains c. PH domains d. S domains

b. SH2 domains

What recognizes phosphatidylinositol-derived lipids? ## Footnote a. SH3 domains b. SH2 domains c. PH domains d. S domains

c. PH domains

What components of the TCR complex can signal? a. TCR b. CD3 c. Zeta chains D. alpha and beta chains

B. CD3 and C, Zeta chains Reminder: the tail end of the TCR itself is too short for ITAMs/ITIMs to be associated with it

How many signaling chains are present in the TCR complex? a. 2 b. 4 c. 6 d. 8 e. 10

c . 6 ( 4 chains from CD3 and 2 from Zeta chains)

How many ITAMs are found in the TCR complex? a. 2 b. 4 c. 6 d. 8 e. 10

e. 10 ( 4in the CD3 complexes, 6 on the Zeta chains )

Describe the early events of T cell activation, in order. a. Ag recognition --\> Syk kinase activated --\> phosphorylation of ITAMs by Syk kinase--\> ZAP-70 docks on phosphorylated ITAMs --\> ZAP-70 Autophosphorylated --\>ZAP-70 phosphorylated adaptor protein--\> ect. b. Ag recognition --\> Lck kinase activated --\> phosphorylation of ITAMs by Lck kinase--\> ZAP-70 docks on phosphorylated ITAMs --\> ZAP-70 Autophosphorylated --\>ZAP-70 phosphorylates adaptor protein--\> ect. c. Ag recognition --\> Lck kinase activated --\> phosphorylation of ITiMs by Lck kinase--\> ZAP-70 docks on phosphorylated ITIMs --\> ZAP-70 Autophosphorylated --\>ZAP-70 phosphorylates adaptor protein--\> ect. d. Ag recognition --\> Lyn kinase activated --\> phosphorylation of ITAMs by Lyn kinase--\> ZAP-70 docks on phosphorylated ITAMs --\> ZAP-70 Autophosphorylated --\>adaptor protein phosphorylated by Lyn Kinase--\> ect.

b. Ag recognition --\> Lck kinase activated --\> phosphorylation of ITAMs by Lck kinase--\> ZAP-70 docks on phosphorylated ITAMs --\> ZAP-70 Autophosphorylated --\>ZAP-70 phosphorylates adaptor protein--\> ect.

A previously healthy 8-year-old boy is infected with an upper respiratory tract virus for the first time. During the first few hours of infection, which one of the following events occurs? ## Footnote a. The adaptive immune system responds rapidly to the virus and keeps the viral infection under control. b. The innate immune system responds rapidly to the viral infection and keeps the viral infection under control. c. Passive immunity mediated by maternal antibodies limits the spread of infection. d. B and T lymphocytes recognize the virus and stimulate the innate immune response. e. The virus causes malignant transformation of respiratory mucosal epithelial cells, and the malignant cells are recognized by the adaptive immune system.

b. The innate immune system responds rapidly to the viral infection and keeps the viral infection under control.

Which of the following is a unique property of the adaptive immune system? a. Highly diverse repertoire of specificities for antigens b. Self-nonself discrimination c. Recognition of microbial structures by both cell-associated and soluble receptors d. Protection against viral infections e. Responses that have the same kinetics and magnitude on repeated exposure to the same microbe

a. Highly diverse repertoire of specificities for antigens

A standard treatment of animal bite victims, when there is a possibility that the animal was infected with the rabies virus, is administration of human immunoglobulin preparations containing anti–rabies virus antibodies. Which type of immunity would be established by this treatment? a. Active humoral immunity b. Passive humoral immunity c. Active cell-mediated immunity d. Passive cell-mediated immunity e. Innate immunity

b. Passive humoral immunity

At 15 months of age, a child received a measles-mumps-rubella vaccine (MMR). At age 22, she is living with a family in Mexico that has not been vaccinated and she is exposed to measles. Despite the exposure, she does not become infected. Which of the following properties of the adaptive immune system is best illustrated by this scenario? a. Specificity b. Diversity c. Specialization d. Memory e. Nonreactivity to self

D. Memory

The two major functional classes of effector T lymphocytes are: a. Helper T lymphocytes and cytotoxic T lymphocytes b. Natural killer cells and cytotoxic T lymphocytes c. Memory T cells and effector T cells d. Helper cells and antigen-presenting cells e. Cytotoxic T lymphocytes and target cells

a. Helper T lymphocytes and cytotoxic T lymphocytes Most effector T cells are either helper T lymphocytes, which promote macrophage and B cell responses to infections, or cytotoxic T lymphocytes, which directly kill infected cells. Natural killer cells are not T lymphocytes. Antigen-presenting cells usually are not T cells. Memory T cells are not effector T cells

Which of the following best describes clonal expansion in adaptive immune responses? a. Increased number of different lymphocyte clones, each clone specific for a different antigen during the course of an infection b. Increased number of different lymphocyte clones, each clone specific for a different antigen during development of the immune system, before exposure to antigen c. Increased number of lymphocytes with identical specificities, all derived from a single lymphocyte due to nonspecific stimuli from the innate immune system d. Increased number of lymphocytes with identical specificities, all derived from a single lymphocyte stimulated by a single antigen e. Increased size of the lymphocytes of a single clone due to antigen-induced activation of the cells

d. Increased number of lymphocytes with identical specificities, all derived from a single lymphocyte stimulated by a single clonal explansion occurs during the activation phase of an adaptive immune response. A single lymphocyte is stimulated to divide by antigen, and the progeny go through several rounds of division until there are many lymphocytes, all with identical specificites, all derived from one cell. The number of different clones is not influenced by antigen exposure. Expansion does not refer to the size of the cells, although activated lymphocytes are larger than their naive precursors

Which of the following statements about the innate immune system is NOT true? a. Innate immunity is present in all multicellular organisms, including plants and insects. b. Deficiencies in innate immunity markedly increase host susceptibility to infection, even in the setting of an intact adaptive immune response. c. Innate immunity is better suited for eliminating virulent, resistant microbes than is adaptive immunity. d. The innate immune response can be divided into recognition, activation, and effector phases. e. The innate immune response against microbes influences the type of adaptive immune response that develops.

c. Innate immunity is better suited for eliminating virulent, resistant microbes than is adaptive immunity

Toll-like receptors (TLRs) are a family of homologous receptors expressed on many cell types and are involved in innate immune responses. Ten different mammalian TLRs have been identified, and several ligands for many of these receptors are known. Which of the following is a TLR ligand? a. Single-stranded RNA b. Transfer RNA c. Double-stranded DNA d. Unmethylated CpG DNA e. Heterochromatin

d. Unmethylated CpG DNA

The signaling pathways triggered by Toll-like receptors typically result in activation of which of the following pairs of transcription factors? a. NFAT and T-bet b. AP-1 and GATA-3 c. Fos and STAT-6 d. NFκB and AP-1 e. Lck and Jun

d. NFκB and AP-1

Which of the following is a receptor on macrophages that is specific for a structure produced by bacteria but not by mammalian cells? a. CD36 (scavenger receptor) b. Fc receptor c. Complement receptor d. Mannose receptor e. ICAM-1

d. Mannose receptor

Macrophages and neutrophils express several enzymes that are involved in biochemical mechanisms that kill ingested microbes. Which of the following is NOT an enzyme expressed by these cells? A. Inducible nitric oxide synthase (iNOS) B. Granzyme B C. Phagocyte oxidase D. Myeloperoxidase E. Lysozyme

B. Granzyme B

A 3-year-old boy, who is small for his age, has a history of pyogenic (pus-producing) infections and cutaneous skin abscesses. Physical examination is remarkable for high fever, enlarged liver and spleen, and swollen cervical lymph nodes. A culture from an abscess on his arm reveals Staphylococcus aureus, a gram-positive bacterium that is also catalase-positive. Immunoglobulin and complement levels are normal. Results of the nitroblue tetrazolium test are consistent with a diagnosis of chronic granulomatous disease (CGD). The boy’s immunodeficiency involves impaired generation of which of the following? A. C5a B. C-reactive protein C. Mannose-binding lectin D. Reactive oxygen intermediates E. Membrane attack complex

D. Reactive oxygen intermediates

A 4-year-old-girl sees her physician because of a severe necrotizing, oropharyngeal herpes simplex viral (HSV) infection. She has a past medical history of cytomegalovirus (CMV) pneumonitis and cutaneous HSV infection. Phenotypic analysis of her blood cells shows an absence of CD56+ and CD16+ cells. There are normal numbers of CD4+ and CD8+ cells in the blood, and serum antibody titers are normal. The patient’s CD8+ T cells were able to kill virally infected target cells in vitro. Which of the following is NOT characteristic of this girl’s immunodeficiency disease? A. Lack of cells whose activation is normally inhibited by self Ag – class I major histocompatibility complex (MHC) B. Impaired granzyme B–dependent killing of virally infected target cells C. Lack of cells that are activated by IL-15 D. Impaired IFN-γ-production during early phases of viral infection E. Failure to form viral peptide-class I MHC complexes

E. Failure to form viral peptide-class I MHC complexes The presence of normal numbers of CD8+ T cells and the ability of these cells to kill virally infected target cells indicated that the class I MHC pathway of viral peptide Ag presentation is intact. The patient's immunodeficiency is due to a lack of NK cells. NK cells express CD56 and/o CD16. NK cells are activated by IL-15 and IL-12, are normally inhibited by recognizing class I MHC on other cells, kill target cells with altered class I MHC expression through a granzyme0B dependent mechanisms (similar to cytolytic T lymphocyte killing), and produce interferon gamma as part of the early innate response to viral infection

Which one of the following statements about inhibitory receptors on natural killer (NK) cells is true? A. Inhibitory receptors on NK cells express ITAM motifs in their cytoplasmic tails. B. Some inhibitory receptors on NK cells recognize HLA-A or HLA-C. C. Some inhibitory receptors on NK cells are members of the integrin family. D. Some inhibitory receptors on NK cells are members of the Toll-like receptor family. E. Inhibitory receptors on NK cells are not expressed on the same NK cells that express activating receptors.

B. Some inhibitory receptors on NK cells recognize HLA-A or HLA-C. NK Inhibitory receptors recognize class I MHC molecules that are normally and constitutively expressed, including various alleles of HLA-A and HLA-C. The cytoplasmic tails of NK inhibitory receptors contain immunoreceptor tyrosine-based inhibitory motifs (ITIMs), bit not immunoreceptor tyrosine-based activation motifs (ITAMs). Some inhibitory recepotrs on NK cells are members of the Ig superfamily, but not the integrin or TLR families. NK cells usually express both activating and inhibitory receptors, and activation is regulated by a balance between signals generated from noth types of receptors. The inhibitory receptors on NK cells bind to self Ag- class I MHC molecules, which are expressed on most normal cells. When activating and inhibitory receptors are simultaneously engages, the inhibitory receptor signals dominate and the NK cell is not activated.

Complement activation in the innate immune system can be initiated in the absence of antibody. Which of the following molecular components of the complement system is involved in initiation of antibody-independent complement activation? A. C1 B. C9 C. Mannose binding lectin D. CR2 E. Mannose receptor

C. Mannose binding lectin

Which of the following is an example of how the innate immune response stimulates or modifies adaptive immunity? A. Tumor necrosis factor (TNF) secreted by helper T cells enhances adhesion molecules on endothelial cells and promotes recruitment of inflammatory cells. B. Interferon (IFN)-γ produced by T helper cells is a potent activator of macrophages, allowing killing of phagocytosed microbes. C. B7-1 expression on antigen-presenting cells is up-regulated in response to signaling through Toll-like receptors, thus enabling costimulation of T cells. D. Infected cells coated by IgG3 are recognized by Fc receptors on natural killer cells, allowing efficient killing of the infected cells. E. Double-stranded RNA of replicating viruses potently stimulates IFN-γ expression by fibroblasts, inducing an “antiviral state” in neighboring, uninfected cells.

C. B7-1 expression on antigen-presenting cells is up-regulated in response to signaling through Toll-like receptors, thus enabling costimulation of T cells.

The principal function of the immune system is: A. Defense against cancer B. Repair of injured tissues C. Defense against microbial infections D. Prevention of inflammatory diseases E. Protection against environmental toxins

C. Defense against microbial infections

Which of the following infectious diseases was prevented by the first successful vaccination? A. Polio B. Tuberculosis C. Smallpox D. Tetanus E. Rubella

C. Smallpox

The estimated number of distinct structures that can be recognized by the mammalian adaptive immune system is A. 1-10 B. 10²-10³ C. 10³-10⁵ D. 10⁷-10⁹ E. ∞

D. 10⁷-10⁹

Which of the following statements best describes the “two-signal requirement” for naive lymphocyte activation? A. Lymphocytes must recognize two different antigens to become activated. B. Lymphocytes must recognize the same antigen at two sequential times to become activated. C. Lymphocytes must recognize antigen and respond to another signal generated by microbial infection to become activated. D. Both naive B and naive T lymphocytes must simultaneously recognize antigen for either to be activated. E. When lymphocytes recognize antigen, the antigen receptors must activate two-signal transduction pathways to become activated.

C. Lymphocytes must recognize antigen and respond to another signal generated by microbial infection to become activated.

In addition to T cells, which cell type is required for initiation of all T cell-mediated immune responses? A. Effector cells B. Memory cells C. Natural killer cells D. Antigen-presenting cells E. B lymphocytes

D. Antigen-presenting cells

A 67-year-old homeless man is brought to the emergency department after being found behind a neighborhood bar in freezing weather. On arrival, he has a shaking chill, fever, and cough productive of blood-tinged sputum. A chest radiograph shows lobar consolidations consistent with bacterial pneumonia. Blood cultures are positive for Streptococcus pneumoniae. Which of the following molecular patterns recognized by Toll-like receptors expressed on the surface of this patient’s phagocytes is important for activating his innate immune system against this grampositive bacterial infection? A. Peptidoglycan B. Double-stranded RNA C. Lipopolysaccharide (LPS) D. Lipoarabinomannan E. Phosphatidylinositol dimannoside

A. Peptidoglycan

The T cell receptor (TCR) complex contains: A. A highly variable antigen coreceptor B. CD28 C. Three homologous CD3 chains, each covalently linked to the TCR α/β heterodimer D. Invariable ζ chains noncovalently linked to the TCR α/β heterodimer E. Igβ

D. Invariable ζ chains noncovalently linked to the TCR α/β heterodimer

A 26-year-old obstetric patient becomes ill during the first trimester of pregnancy with fever and lymphadenopathy. She is found to have a rising titer of anti-Toxoplasma gondii antibodies. She delivers a full-term baby with no apparent signs of in utero infection. The best test to diagnose acute infection in the neonate (a newborn infant less than four weeks old) would be a parasite-specific ELISA for which isotype of immunoglobulins? A. IgA B. IgD C. IgE D. IgG E. IgM

E. IgM

An antibody preparation is being used in a laboratory protocol to study B cell. The preparation doesn’t activate the cells or cause crosslinking. It doesn’t cause precipitation of its purified ligand, and it doesn’t cause agglutination of latex beads covalently coupled to its ligand. Which of the following is the most likely antibody preparation? A. Monoclonal anti-CD19 B. Monoclonal anti-CD56 C. Papain-treated anti-CD19 D. Papain-treated anti-CD56 E. Pepsin-treated anti-CD19 F. Pepsin-treated anti-CD56

D. Papain-treated anti-CD56

A 3-year-old boy is evaluated for a possible immunodeficiency. He has suffered repeated infections of mucosal-surface pathogens and has shown delayed development of protective responses to the standard childhood vaccination. Immuno-electrophoresis of his serum demonstrates the absence of a macroglobulin peak and his sputum is devoid of secretory IgA. Normal numbers of B cells bearing monomeric IgM are found by flow cytometry, and serum level of monomeric IgA, IgE, and each of the 4 subclasses of IgG are normal. Which of the following deficiencies could account for these findings? A. Absence of CD40 B. Absence of J chains C. Absence of IL-4 D. Absence of dendritic cells E. Absence of tissue macrophages

B. Absence of J chains

Toxoplasma gondii is an intracellular parasite that lives inside phagocytic and nonphagocytic cells by generating its own intracellular vesicle. This may allow it to avoid recognition and killing by CD8+ lymphocytes, which require the presentation of foreign peptides transported into the endoplasmic reticulum and loaded onto MHC molecules that have A. a β2 domain instead of β2 macroglobulin B. invariant chains C. a peptide-binding groove D. a single transmembrane domain E. two similar chains

D. a single transmembrane domain

A patient is shown to a have a mutation in his BTK tyrosine kinase gene. Which of the following stages of lymphocyte differentiation is blocked in this patient? A. Differentiation of mature B cells into plasma cells B. Generation of memory cells C. Differentiation of pre-BV cells into immature B cells D. Negative selection of B cells in the bone marrow E. Activation of mature B cells

E. Activation of mature B cells

A patients presents with recurrent bacterial infections and is found to have low serum levels of IgA and IgG, but elevated concentrations of serum IgM. Flow cytometry of his LN cells reveal an absence of immune cells expressing CD40L. In which immune cells this surface marker is normally found? A. B cells expressing membrane IgG B. Activated CD4+ T helper cells C. NK cells in the spleen D. All lymphocytes in peripheral lymphoid tissues E. CD19 B cells in the bone marrow

B. Activated CD4+ T helper cells

A 5-year-old boy has a history of recurrent pneumococcal pneumonia, Pneumocystis carinii pneumonia (PCP), and bacterial ear infections. His maternal uncle and an older brother experienced the same symptoms, but he has an older sister who is healthy. Laboratory studies indicate normal numbers of B cells and T cells, and the serum contains mostly IgM and very little IgG. Which of the following immune cell interactions does not function normally in this patient? A. Dendritic cell and CD4+T cell B. Dendritic cell and CD8+T cell C. B cell and CD4+T cell D. B cell and CD8+ T cell E. CD4+T cell and CD8+ T cell

C. B cell and CD4+T cell

A 40-year-old male patient has a genetic deficiency leading to the expression of nonfunctional CD40 ligand (CD40L). In addition to defects in humoral immunity, the patient showed an impaired cell-mediated immunity as evident by increased susceptibility to infections caused by intracellular pathogens. Which statement correctly describes CD40L-dependent mechanisms involved in cell-mediated immunity? A. CD40L-dependent isotype switching is required to produce antibody isotypes that activate T cells. B. CD40 ligand is required for killing of CD40-expressing infected cells by CTLs. C. CD40 ligand is required for maturation of CD4+ T cells in the thymus. D. CD40 ligand on T cells binds to CD40 on macrophages and enhances their phagocytic and Ag-presenting properties. E. CD40 ligand on T cells binds to B7-1 and B7-2 on APCs, and this enhances the function of the APCs

D. CD40 ligand on T cells binds to CD40 on macrophages and enhances their phagocytic and Ag-presenting properties.

Class I MHC-restricted T cells against tumor antigens can be found in patients with various types of cancer. Which mechanism correctly explains activation of naïve CD8+ T cells specific for mutated self-antigens in tumors? A. Malignant transformation of CD8+ T cells B. Tumor secretion of T cell-activating cytokines C. Cross reaction of microbe-specific CD8+ T cells with tumor antigens D. Cross-presentation of tumor antigens by APCs E. Antigenic modulation

D. Cross-presentation of tumor antigens by APCs

Which one of the following cell types would be most potent at activating naive T cells? A. Kupffer cells B. B cells C. Follicular dendritic cells D. Neutrophils E. Langerhans cells

E. Langerhans cells

Which one of the following descriptions of cytokine interleukin-2 is NOT true? A. Expression of its gene requires multiple transcription factors, such as Fos, Jun, and NFAT. B. It acts as an autocrine growth factor for T cells. C. It binds to CD25 on the cell membrane of T cells. D. It is only involved in the proliferation of helper T cells and not CTLs. E. It primes T cells to apoptosis.

E. It primes T cells to apoptosis.

CD8 is a protein that functions as a coreceptor for a subset of T cells and plays a significant role in all of the following EXCEPT: A. Recognition of peptide antigen bound to class I MHC molecules B. Maturation of MHC class I–restricted T cells C. Infection of T cells by human immunodeficiency virus (HIV) D. Signaling via Lck tyrosine kinase to initiate T cell activation E. Strengthening the binding of T cells to antigen-presenting cells, albeit with low affinity

C. Infection of T cells by human immunodeficiency virus (HIV)

Both CD28 and CTLA-4 are receptors on T cells that are critical for regulating T cell activation. In which one of the following ways does CD28 differ from CTLA-4? A. Only CD28 binds the costimulatory ligands B7-1 and B7-2 expressed on professional antigen-presenting cells. B. CD28 counteracts positive, pro-proliferative T cell signals delivered by CTLA-4. C. CD28 is constitutively expressed on naive T cells, whereas CTLA-4 is expressed on activated T cells. D. CD28 binds its ligand with 10-fold greater affinity than does CTLA-4. E. CD28 is important for delivering “signal 1” for T cell activation, whereas CTLA-4 is important for delivering “signal 2.”

C. CD28 is constitutively expressed on naive T cells, whereas CTLA-4 is expressed on activated T cells

A 2-year-old boy suffers from recurrent bacterial infection of his ears, sinuses, lungs, and skin; laboratory studies indicate absence of sialylated Lewis X on his leukocytes. He is diagnosed with leukocyte adhesion deficiency type 2 (LAD-2). Which type of adhesive interaction required for leukocyte migration is defective in this boy? A. E-selectin ligand binding to E-selectin B. CD4 binding to class II MHC C. VLA-4 binding to VCAM-1 D. Ig Fc receptor binding to Ig-coated cells E. LFA-1 binding to ICAM-1

A. E-selectin ligand binding to E-selectin

Neonates, elderly persons, and otherwise immunocompromised patients are particularly susceptible to infections with Listeria monocytogenes. These patients typically have fever and chills, often progressing to hypotension and septic shock. In healthy individuals, however, intracellular microbes are usually effectively phagocytosed and killed by macrophages, which become activated via: A. CD40L-CD40 interactions between activated T helper cells and macrophages B. CD28-B7 interactions between activated T cells and macrophages C. Fas ligand–Fas interactions between activated cytotoxic T lymphocytes and macrophages D. TCR-MHC class II interactions between activated T helper cells and macrophages E. LFA-1–ICAM-1 interactions between activated T cells and macrophages

A. CD40L-CD40 interactions between activated T helper cells and macrophages

Which one of the following statements about T cells involved in an immune response is NOT true? A. Activated T cells receive survival signals from antigen during an infection. B. Activated T cells contribute to the activation of antigen-presenting cells via CD40 C. Memory T cells generated during a primary immune response express high levels of interleukin-2 receptors and actively proliferate long after the primary response is completed D. The major effector function of helper T cells is to activate macrophages and other cells by releasing cytokines. E. When an infection is eliminated, activated T cells die by apoptosis.

C. Memory T cells generated during a primary immune response express high levels of interleukin-2 receptors and actively proliferate long after the primary response is completed

Which one of the following statements about the molecules B7-1 and B7-2 is NOT true? A. B7-1 and B7-2 expression on antigen-presenting cells (APCs) is upregulated by the presence of “danger” signals, such as lipopolysaccharide, as well as cytokines, such as interferon (IFN)-γ. B. B7-1 and B7-2 are expressed at low levels on some resting APCs. C. Induction of B7-1 usually occurs before the induction of B7-2 in an immune response. D. B7-1 and B7-2 bind to CD28 on T cells and provide “second signals” for naive T cell activation. E. Activated helper T cells can induce expression of B7-1 and B7-2 on APCs via CD40L binding to CD40.

C. Induction of B7-1 usually occurs before the induction of B7-2 in an immune response.

An experiment is performed in which a point mutation is introduced randomly into the Zap-70 gene for a particular strain of mice. The mutant mice display a defect in T cell development. However, precursor T cells isolated from the thymus of these mice show normal expression levels of Zap-70 of the correct molecular weight. On further in vitro analysis, the mutant Zapis found to bind to ITAM motifs in the cytoplasmic tail of the ζ chain, but only when the ζ is phosphorylated. No phosphorylated LAT is detected, however. Given these data, in which of the following protein domains is the mutation most likely to be present? A. Pleckstrin homology (PH) domain B. Proline-rich (PR) domain C. SH1 domain D. SH2 domain E. SH3 domain

C. SH1 domain

Which one of the following accurately depicts the correct order of events in a TCR signal transduction pathway? A. TCR → Lck → Zap-70 → LAT → Grb-2 → SOS → Ras → Erk → Fos B. TCR → Lck → Zap-70 → LAT → SOS → Grb-2 → Ras → Erk → Fos C. TCR → Lck → ITK → LAT → Grb-2 → SOS → Ras → Erk → Fos D. TCR → Lck → Zap-70 → LAT → SOS → Grb-2 → Ras → Erk → Jun E. TCR → Lck → Zap-70 → LAT → PLC → DAG → calcium release

A. TCR → Lck → Zap-70 → LAT → Grb-2 → SOS → Ras → Erk → Fos

A patient recently diagnosed with Systemic lupus erythematosus (SLE) is experiencing significant symptoms of 3 weeks duration that include edema and skin rash. Her serum blood urea nitrogen (BUN) and creatinine levels are increased, and a biopsy of her kidney shows IgG and C3b at the glomerular basement membrane. Her serum complement levels are monitored over time. Which of the following findings would be most consistent with a worsening clinical course? A. A decline in C9 levels B. A decline in C3 and CD4 levels C. An increase in Factor P levels D. An increase in C1 inhibitor levels E. A decline in C7 levels

B. A decline in C3 and CD4 levels