Exam 1: Mock Exam Flashcards
Cell-mediated immunity is largely T-cell-driven, utilizing Th1 (CD4+) and cytotoxic T cell (CD8+), and is involved in responses to viral infection, graft rejection, chronic inflammation and tumor immunity. Which of the following is mismatched?
A. CD8 T cell: cytotoxicity B. CD4 TH2 cell: cytotoxicity C. CD4 TH1 cell: macrophage activation D. CD4 TH2 cell: B-cell activation E. CD4 TH1 cell: HIV infection
B. CD4 TH2 cell: cytotoxicity
Nearly one-third of the global population is infected with helminth parasites, rendering them among the most prevalent infectious agents in the world today, and they are responsible for many debilitating diseases and syndromes. Which of the following types of cells are notable for their presence at the sites of helminth infections?
A. Basophils B. Eosinophils C. Lymphocytes D. Monocytes E. Neutrophils
B. Eosinophils
The term “central tolerance” has been used to describe a state which is established by mechanisms that operate during development of immune cells in the primary lymphoid organs, such as thymus and bone marrow. The central tolerance prevents immature immune cells expressing self antigen-specific receptors from becoming functionally mature cells. Which of the following is incorrect concerning immune tolerance?
A. Tolerance induction is antigen-specific.
B. Tolerance results from inactivation and/or elimination of B and/or T cells.
C. Tolerance can be induced in both young and old individuals.
D. Immature neutrophils are more susceptible to tolerance than mature
neutrophils.
E. The breakdown of tolerance can result in autoimmunity.
D. Immature neutrophils are more susceptible to tolerance than mature
Two separate properties of the MHC make it difficult for pathogens to evade immune responses. First, the MHC is polygenic: it contains several different MHC class I and MHC class II genes, so that every individual possesses a set of MHC molecules with different ranges of peptide-binding specificities. Second, the MHC is highly polymorphic; that is, there are multiple variants of each gene within the population as a whole. When the sequences of different MHC class I molecules are compared, the variation between molecules is concentrated within which of the following?
A. Areas of the molecule that bind CD4
B. Areas of the molecule that bind to the T cell receptor and to the antigenic peptide
C. Beta 2 microglobulin
D. the transmembrane domain of the alpha chain
E. the alpha 1 domain (the N terminal domain of the alpha chain)
B. Areas of the molecule that bind to the T cell receptor and to the antigenic peptide
The adaptive humoral immune response can be divided into primary and secondary responses. The primary immune response occurs when an antigen comes in contact to the immune system for the first time. The secondary immune response occurs when the second time (3rd, 4th, etc.) the person is exposed to the same antigen. The primary and secondary antibody responses differ in which of the following?
A. the predominant isotype generated.
B. the number of lymphocytes responding to antigen.
C. the speed at which antibodies appear in the serum.
D. the biologic functions manifested by the Ig isotypes produced.
E. All of the above.
E. All of the above.
The family of cytokines includes the inflammatory cytokines, growth factors, and chemokines. Cytokines have important roles in chemically induced tissue damage repair, in cancer development and progression, in the control of cell replication and apoptosis, and in the modulation of immune reactions such as sensitization. Which of the following statements regarding the functional properties of cytokines is false?
A. They typically have pleiotropic properties.
B. They often exhibit functional redundancy.
C. They often display antigen specificity.
D. They exhibit synergistic or antagonistic properties.
E. They assist in the regulation and development of immune effector cells.
C. They often display antigen specificity.
Leukocytes have a primary role in immune function. There are normally six different types of leukocyte found in the circulating blood: neutrophils, eosinophils, basophils,
monocytes, lymphocytes, and occasional plasma cells. The most abundant type of leukocyte in human peripheral blood is:
A. eosinophil B. basophil C. neutrophil D. monocyte E. lymphocyte
C. neutrophil
The difference between tolerance and immunity depends upon the maturation status of the antigen presenting dendritic cells. What is the T-cell outcome of an antigen presentation event by a mature dendritic cell?
A. Anergy B. Apoptosis C. Activation D. Ignorance E. Suppression
C. Activation
Extracellular pathogens replicate and/or persist on mucosal surfaces or in host tissues outside host cells and may rapidly spread or establish an infection. A person developed an extracellular bacterial infection, and lgM was made in response what is the most important protective function of IgM in this infection?
A. Antibody-dependent cell cytotoxicity B. Complement activation C. Direct lysis of bacterial cells D. Neutralization of bacterial toxins E. Opsonization
B. Complement activation
A virus is a small infectious organism - much smaller than a fungus or bacterium - that must invade a living cell to reproduce (replicate). A person develops a viral infection and both T and B cells become activated to fight the infection. In which way is antigen recognition by B cells different from antigen recognition by T cells?
A. B cells home to the paracortex of lymph nodes where they recognize the antigens trapped by helper T cells
B. B cells recognize the antigens that have been processed and presented by follicular dendritic cells
is a small infectious organism – much smaller than a fungus or bacterium – that
C. B cells undergo receptor editing to change receptors that fail to bind to an antigen
D. B cells utilize membrane immunoglobulin molecules to bind to antigen in its natural state
E. The antigen receptors on a single B cell have a broad specificity, and are able to recognize several chemically unrelated antigens
D. B cells utilize membrane immunoglobulin molecules to bind to antigen in its natural state
The intracellular signal initiated by antigen binding to the T-cell receptor is generated by which set of molecules expressed on the T cell membrane?
A. CD3 B. CD4 C. CD28 D. CD45 E. CD152
A. CD3
Initial descriptions of TCRs were made 30 years ago primarily through similarity with immunoglobulin DNA sequences. Which of the following statements regarding T-cell receptor recognition of antigen is correct?
A. T-cell receptors recognize antigen only as a peptide bound to an MHC molecule.
B. T-cell receptors recognize antigens in their native form.
C. T-cell receptors, like B cell immunoglobulins, can recognize carbohydrate, lipid, and protein antigens.
D. Antigen processing occurs in extracellular spaces.
E. Like α/β T cells, γ/δ T cells are also restricted to the recognition of antigens presented by MHC molecules.
A. T-cell receptors recognize antigen only as a peptide bound to an MHC molecule.
The notion that specificity in adaptive immune responses derives from a clonal distribution of antigen receptors, coupled with requisite receptor ligation for activation, is the central argument of the generally accepted clonal selection hypothesis. Simply put, while billions of different antigen receptors can be made (in terms of antigen- binding specificity), each lymphocyte makes only one kind. Which of the following cell types do NOT have clonally distributed antigen receptors?
A. Natural killer cells B. Cytotoxic T lymphocytes C. Naive B cells D. Helper T lymphocytes E. Memory B cells
A. Natural killer cells
An individual does not make an immune response to a self-protein because
A. self-proteins cannot be processed into peptides. B. peptides from self-proteins cannot bind to MHC class I. C. peptides from self-proteins cannot bind to MHC class II. D. lymphocytes that express a receptor reactive to a self-protein are deleted by mechanisms of the central tolerance. E. developing lymphocytes cannot rearrange V genes required to produce a receptor for self- proteins.
D. lymphocytes that express a receptor reactive to a self-protein are deleted by
mechanisms of the central tolerance.
A complete blood count (CBC) is a blood test used to evaluate your overall health and detect a wide range of disorders, including infections, anemia, and leukemia. CBC that indicates an elevated number of neutrophils would most likely consistent with which of the following conditions?
A. Chronic viral infection B. Acute viral infection C. Chronic helminth infection D. Acute bacterial infection E. Fungal infection
D. Acute bacterial infection
Checking the number of white blood cells in the blood is usually part of a CBC test. It may be used to look for conditions such as infection, inflammation, allergies, and leukemia. What is the term generally used to describe all white blood cells?
A. hematopoietic cells B. myeloid progenitor C. dendritic cells D. monocytes E. leukocytes
E. leukocytes
Which of the following is the site at which lymphocytes can leave the blood and gain entry into the lymph nodes and what lymphocyte cell surface protein mediates such access?
A. Lymphoid follicle: CD4
B. Germinal center: CD62L (L-selectin)
C. Lymphoid follicle: CD62L (L-selectin)
D. Periarterial lymphatic sheath (PALS): CCR7
E. High endothelial venules (HEV): CD62L (L-selectin)
E. High endothelial venules (HEV): CD62L (L-selectin)
Persons with helminth infections mount immunologic responses that involve IgE and eosinophils. Which two cytokines are most important for these responses to occur?
A. IL-1 and tumor necrosis factor (TNF) B. IL-4 and IL-5 C. IL- 10 and transforming growth factor beta (TGF-beta) D. IL-12 and interferon gamma (IFN -y) E. IFN-alpha and IFN-beta
B. IL-4 and IL-5
A 36-year-old woman with severe allergy to yellow jackets was stung multiple times at a soccer game. Within minutes she developed respiratory distress and became unconscious. Which mediator is primarily responsible for this reaction?
A. Complement B. IgG C. Histamine D. TNF E. Norepinephrine
C. Histamine
Antigens from which one of the following microbes would be presented on MHC class I molecules by professional APCs?
A. Ascaris lumbricoides (a large roundworm)
B. Candida albicans (an opportunistic pathogenic yeast) C. Hemophilus influenzae (a Gram-negative bacterium)
D. Influenza virus (commonly known as the flu virus)
E. Streptococcus pneumoniae (a gram-positive bacterium)
D. Influenza virus (commonly known as the flu virus)
