Reference no: EM13847347

1. Vaccinations helped eradicate smallpox.

2. The first line of defense against pathogens does not involve immune cells such as macrophages and neutrophils.
3. Most likely, a patient depleted of eosinophils and basophils will not struggle to overcome bacterial infections.
4. A patient depleted of eosinophils and basophils will most likely struggle to overcome parasitic infections.
5. Basophils are not the most abundant leukocytes.
6. Having an immune response to an antigen is always beneficial to health.
7. You are studying immune responses to 2 drugs, Drug A has a large, and easily degradable structure, whereas Drug B is soluble with a small chemical structure; therefore, Drug A must be more immunogenic and will induce stronger immune responses than Drug B.
8. PRRs can only recognize PAMPs found in bacteria.
9. PAMPs are sometimes derived from molecules coded by certain Homo sapiens genes.
10. PRRs can recognize DAMPs released from non-infected Homo sapiens cells.
11. Typically, necrotic, but not apoptotic, Homo sapiens cells release DAMPs.
12. Flushing by urine is a part of the mechanical barrier to infection in the urogenital tract.
13. Defensins can cause the disruption of pathogen membrane's integrity and function, which ultimately leads to the lysis of microorganisms.
14. Defensins contribute to the antimicrobial action of granulocytes.
15. Enzymes in phagocytic cells catalyze the synthesis of hypochlorous acid and nitric oxide, which kill pathogens.
16. The origin of the word "Toll" in Toll-like receptors (TLRs) is not the song "For Whom the Bell Tolls" by the American rock band Metallica.
17. TLRs are a type of PRRs.
18. PAMPs are a type of PRRs.
19. DAMPs are a type of PRRs.
20. NLRs are a type of PRRs.
21. The PAMP-specificity of TLRs is not determined by their transmembrane regions.
22. TLRs are encoded by genes that undergo gene rearrangement during cell differentiation.
23. TLR signaling can activate the transcription factor NF-κB, resulting in the induction of the proinflammatory cytokine expression.
24. TLRs differ from scavenger receptors in that they bind to common repetitive arrays on microbial surfaces.
25. TLRs differ from scavenger receptors in that they stimulate a pathway that causes enzymatic degradation of the microbe to which they bind.
26. TLRs differ from scavenger receptors in that they are soluble receptors that bind to microbes in extracellular spaces.
27. TLRs differ from scavenger receptors in that they mediate signal transduction pathways, causing cytokine production.
28. A typical extracellular TLR region is composed of multiple copies of a lysine-rich repeat.
29. Some TLRs detect microbes or their components delivered through receptor-mediated endocytosis. 30. TLRs are located on the plasma membrane and the mitochondrial outer membrane.
31. TLRs are located on the plasma membrane and endosomal membranes.
32. TLRs are not located inside inflammasomes.

 

33. Unlike inflammatory cytokines, TLRs are never secreted.
34. TNF-α, IL-6 and IL-12 are endogenous pyrogens (raising body temperature).
35. Inflammasomes are key signaling platforms that detect pathogenic microorganisms.
36. Activation of the inflammasomes can induce cell pyroptosis.
37. A virus can inhibit MHC class I expression to avoid recognition by NK cells.
38. The covalent binding of antibodies with antigens strengthens the non-covalent binding between these two entities.
39. Only the heavy chain of an antibody molecule has a variable region.
40. Only the light chain of an antibody molecule has a variable region.
41. The number of variable amino acids (AAs) is not the same in all κ variable regions.
42. The number of variable AAs is not the same in all λ variable regions.
43. The five isotypes of immunoglobulin are defined based on the differences in their light-chain constant regions.
44. The five isotypes of immunoglobulin are defined based on the differences in their heavy-chain constant regions.
45. The five isotypes of immunoglobulin are defined based on the differences in their light-chain variable regions.
46. The five isotypes of immunoglobulin are defined based on the differences in their heavy-chain variable regions.
47. The five isotypes of immunoglobulin are defined based on the differences in their heavy-chain variable and constant regions.
48. There is no functional difference between the κ and λ immunoglobulin light chains.
49. κ associates with only particular heavy-chain isotypes.
50. The κ locus encodes a single C segment, whereas the λ locus has more than one.
51. Light chains possess only framework regions, not hypervariable regions.
52. On the heavy-chain immunoglobulin gene locus, recombination signal sequences (RSSs) flank the 5′ side of the V segment, both sides of the D segment, and the 3′ side of the J segment.
53. On the heavy-chain immunoglobulin gene locus, RSSs flank the 5′ side of the V segment, the 5′ side of the D segment, and the 5′ side of the J segment.
54. On the heavy-chain immunoglobulin gene locus, RSSs flank the 3′ side of the V segment, both sides of the D segment, and the 3′ side of the J segment.
55. On the heavy-chain immunoglobulin gene locus, RSSs flank the 3′ side of the V segment, both sides of the D segment, and the 5′ side of the J segment.
56. On the heavy-chain immunoglobulin gene locus, RSSs flank both sides of the V segment, both sides of the D segment, and the both sides of the J segment.
57. The enzyme responsible for recombining V, D, and J segments during somatic recombination is called V(D)J recombinase.
58. The enzyme responsible for recombining V, D, and J segments during somatic recombination is called terminal deoxynucleotidyl transferase.
59. The enzyme responsible for recombining V, D, and J segments during somatic recombination is called exonuclease.
60. The enzyme responsible for recombining V, D, and J segments during somatic recombination is called DNA polymerase.
61. The enzyme responsible for recombining V, D, and J segments during somatic recombination is called DNA ligase.
62. Artemis is a component of V(D)J recombinase.
63. Terminal deoxynucleotidyl transferase is not a component of V(D)J recombinase.
64. RAG-1/RAG-2 are components of V(D)J recombinase.
65. DNA ligase IV is a component of V(D)J recombinase.
66. DNA-dependent protein kinase and the associated Ku protein are components of V(D)J recombinase. 67. An epitope is the specific part of the antigen that is recognized by an antibody and binds to the complementarity-determining regions in the antibody variable domains.
68. An epitope is the specific part of the antigen that is recognized by an antibody and binds to the complementarity-determining regions in the antibody variable domains and to a part of constant heavy chain region.

 

69. Epitopes are sometimes referred to as antigenic determinants.
70. Epitopes can be part of a protein or can be carbohydrate or lipid structures present in the glycoproteins, polysaccharides, glycolipids, and proteoglycans of pathogens.
71. The antibody secreted by a plasma cell has a different specificity for antigen than the immunoglobulin expressed by its B-cell precursor.
72. The amino-terminal regions of heavy and light chains of different immunoglobulins all differ in amino acid sequence.
73. The heavy-chain constant region is responsible for the effector function of immunoglobulins.
74. Usually, only about 10-25 of the 50-70 CDR AA residues of a certain antibody participate in the interaction with any given epitope, meaning that an antibody may harbor a large number of different paratopes; this is likely to increase antibody cross-reactivity.
75. Usually, only about 10-25 of the 50-70 CDR AA residues of a certain antibody participate in the interaction with any given epitope, meaning that an antibody may harbor a large number of different paratopes; this is unlikely to increase antibody cross-reactivity.
76. Usually, only about 10-25 of the 50-70 CDR AA residues of a certain antibody participate in the interaction with any given epitope, meaning that an antibody may harbor a large number of different paratopes; this is likely to decrease antibody cross-reactivity.
77. Usually, only about 10-25 of the 50-70 CDR AA residues of a certain antibody participate in the interaction with any given epitope, meaning that an antibody may harbor a large number of different paratopes; this is unlikely to decrease antibody cross-reactivity.
78. Usually, only about 10-25 of the 50-70 CDR AA residues of a certain antibody participate in the interaction with any given epitope, meaning that an antibody may harbor a large number of different paratopes, which is likely to have no effect on antibody cross-reactivity.
79. Typically, the T-cell receptor (TCR) does not bind to free peptides in solutions.
80. T-cell determinants are limited to exposed portions of the antigen on the surface of any given antigen molecule.
81. There is no lower limit on the number of AA residues to bind to MHC class I, but there is an upper limit.
82. There is a lower limit on the number of AA residues to bind to MHC II, but there is no upper limit.
83. CD8 interacts with MHC class I.
84. A distinction between the innate and adaptive immune systems includes the capacity of only one system to recognize virally infected cells.
85. A distinction between the innate and adaptive immune systems includes the ability of cells of only one system to mediate cell cytotoxicity.
86. When an individual encounters Gram-negative bacteria (if the organisms survive the physical and chemical barriers), they may be recognized on first encounter by the innate immune system via antibodies.
87. When an individual encounters Gram-negative bacteria (if the organisms survive the physical and chemical barriers), they may be recognized on first encounter by the innate immune system via TLRs.
88. When an individual encounters Gram-negative bacteria (if the organisms survive the physical and chemical barriers), they may be recognized on first encounter by the innate immune system via the membrane attack complex (MAC).
89. Typically, natural killer (NK) cells proliferate in response to antigen.
90. Typically, NK cells kill non-phagocytosed target cells extracellularly.
91. Typically, NK cells kill phagocytosed target cells intracellularly.
92. Typically, NK cells do not kill their target cells by intracellular digestion.
93. NK cells are not a subset of polymorphonuclear cells.
94. NK cells are not effective in providing immunosurveillance against Gram-positive bacteria.
95. NK cells can mediate ADCC.
96. Killer-cell inhibitory receptors (KIRs) expressed by human NK cells bind to complement receptors to prevent killing of normal Homo sapiens cells.
97. KIRs expressed by human NK cells bind to MHC class I to prevent killing of normal Homo sapiens cells.
98. KIRs expressed by human NK cells do not bind to MHC class II.
99. KIRs expressed by human NK cells bind to immunoglobulin to prevent killing of normal Homo sapiens cells.

 

100. KIRs expressed by human NK cells bind to TLRs to prevent killing of normal Homo sapiens cells. 101. Increased production of antibody by the immune system is driven by the presence of antigen.
102. Innate immunity is deployed only during the primary response and adaptive immunity begins during a secondary response.

103. Booster shots are required because repeated exposure to antigen builds a stronger immune response.
104. A single molecule of bound IgM can activate the C1q component of the classic complement pathway.

105. The enzymes that cleave C3 and C4 are referred to as convertases.
106. C3a and C3b are fragments of C3 that are generated by proteolytic cleavage mediated by two different enzyme complexes.
107. Enveloped viruses cannot be lysed by complement because their outer envelopes are resistant to pore formation by the membrane attack complex (MAC).
108. MBL has a function in the lectin pathway analogous to that of IgM in the classical pathway, and MASP-1 and MASP-2 take on functions analogous to C1 components.
109. Either factor H or factor I can inactivate C3b.
110. Our bodies face the greatest onslaught from foreign invaders through our skin.
111. The gene for the T-cell receptor must be cut and spliced together before it can be expressed.
112. Autoimmunity and immunodeficiency are two different terms for the same set of general disorders. 113. If you receive intravenous anti-venom immunoglobulin to treat a snakebite, you will be protected from the venom of this snake in the future (even if you have not mounted your own response to the venom), but not venoms from other types of snakes.
114. Innate and adaptive immunity work collaboratively to mount an immune response against pathogens.
115. The TCR-encoding genomic sequences in our circulating T cells are not the same as those our parents carry in their T cells.
116. Both the innate and adaptive arms of the immune response will be capable of responding more efficiently during a secondary response.
117. Patients with genetic (function-decreasing) NADPH oxidase mutations will have trouble resolving common viral infections.
118. Patients with genetic (function-decreasing) NADPH oxidase mutations will have trouble with bacterial infections.
119. Genetic (function-decreasing) NADPH oxidase mutations are unlikely to cause impaired class switching in B cells, resulting in elevated IgM antibody levels.
120. Genetic (function-decreasing) NADPH oxidase mutations are unlikely to cause decreased activities of defensins.
121. Patients with genetic (function-decreasing) NADPH oxidase mutations will likely experience more severe problems with Gram-negative than with Gram-positive microorganisms.
122. In patients with genetic (function-decreasing) NADPH oxidase mutations, the alternative pathway of complement activation will be extremely inefficient.
123. In patients with genetic (function-decreasing) NADPH oxidase mutations, macrophages and neutrophils will display normal phagocytosis, but impaired or no killing of ingested microbes.
124. In patients with genetic (function-decreasing) NADPH oxidase mutations, macrophages and neutrophils will display impaired phagocytosis, but normal killing of ingested microbes.
125. Genetic (function-decreasing) NADPH oxidase mutations are unlikely to diminish the opsonizing capacity of IgM.
126. Early diagnosis and antibiotic prophylaxis would be desirable in patients with genetic function- decreasing NADPH oxidase mutations.

 

Question 2. Immune responses to antigens may be categorized as primary or secondary responses. Re-exposure to a previously encountered infectious agent (pathogen) stimulates a secondary immune response to that pathogen. This response is more rapid and potent than the response following the primary exposure. What are the reasons for these differences? [In this context, asses the following statements (127-140) as factually correct (= true, T) or incorrect (= false, F)]:

127. The increased functionality of TCRs partially due to V(D)J recombination processes that involve the RAG1 and RAG2 proteins.
128. The increased signaling capability of T-cell co-receptors, while the primary signals being mediated through the TCRs binding specific, pathogen-derived peptide-MHC complexes.

129. The enhanced innate immune responses during or after the re-expose to the pathogen. 130. The improved reactivity of the thioester group of C3b on the pathogen surface.
131. The better receptor editing in both T and B cells.
132. The improved covalent linkage of C4b on the pathogen surface.

133. The presence of high levels of activated complement component C5 that leads to formation of a MAC (membrane attack complex) that kills the organism.
134. The presence of IgD antibody in serum that can bind to macrophages and enhance their activation. 135. The presence of memory T and B cells that are readily activated to eliminate the infectious agent. 136. The presence of regulatory T cells capable of modulating the response.

137. The augmented expression of TLRs (toll-like receptors) on antigen-presenting cells.
138. The increased affinity of antibodies partially due to somatic hypermutation processes.
139. The improved functionality of antibodies partially due to isotype switch recombination processes. 140. The improved functionality of properdin, which stabilizes the C3bBb convertase.