MIMM 214 - Practice midterm questions

pdf

School

McGill University *

*We aren’t endorsed by this school

Course

214

Subject

Biology

Date

Jan 9, 2024

Type

pdf

Pages

Uploaded by BarristerOryxPerson174

Winter 2022 – MIMM 214 Midterm Practice questions 1 MIMM 214- Practice Questions Try to do these without looking at your notes Questions: 1. Select all that apply. Which of the following is/are a primary lymphoid organ? A. Bone marrow B. Peyer’s patches C. Lymph node D. Thymus E. Spleen 2. Which lineage to NK cells belong to? 3. Which cells are granulocytes? 4. If your immune system attacks against self, that is known as: 5. If your immune system attacks against safe, non-self, that is known as: 6. What is the difference between negative and clonal selection? 7. What is the primary cell type involved in humoral immunity? What is the name of the molecule secreted specifically by this cell-type? 8. What is a cytokine? A. A cell-surface receptor B. An intracellular transcription factor C. An enzyme D. A secreted messenger protein E. A specific region of an antigen 9. Adaptive immunity is mediated by which key cells: 10. True or false. The innate immune response improves with repeated exposure (i.e. infection or vaccination). 11. Which of the following statements is TRUE? A. All PRRs induce phagocytosis B. Monocytes produce extracellular matrices called NETs to trap microorganisms as part of the innate immune response C. CD47 is one of the most potent “eat me” signals, and is a common marker for apoptotic cells

Winter 2022 – MIMM 214 Midterm Practice questions 2 D. To cause inflammation, a pathogen must always breach one of the body’s barriers 12. Why is human skin resistant to colonization by E. coli despite exposure to it? 13. Select all: Which cells are involved in innate immunity? A. Neutrophils B. T cells C. Conventional DCs D. NKs E. Monocytes F. B cells 14. Select all: Which cells are phagocytic? A. Macrophages B. DCs C. B cells D. NK cells E. Neutrophils 15. Name 3 key roles that the phagosome/phagolysosome plays in the immune response. 16. What is a NET? 17. What would happen if we remove (knock-out) the genes that encode for the adhesion molecules on endothelial cells? 18. In which tissue/organ are complement proteins mostly produced? A. Lymph node B. Spleen C. Liver D. Kidney E. Thymus 19. Which of the following complement proteins is an opsonin? A. C2a B. C3b C. C4b D. C3bBb 20. A patient has reduced levels of C3 convertase compared to a healthy individual with the same extracellular pathogen infection. You measure the levels of different complement proteins and notice that it has low levels of C3 convertase, normal levels of C1q, and low levels of Mannose-binding lectin. Based on these results, which component of the immune system is deficient in the patient?

Winter 2022 – MIMM 214 Midterm Practice questions 3 21. Membrane-attack complex involves which two key complement proteins? 22. Which of the following statements is TRUE? A. Innate lymphoid cells (ILCs) are found primarily in circulation B. Cytokines are only produced by antigen-presenting cells (APCs) C. Type I interferon is induced following infection by extracellular bacterial pathogens D. CD47 provides a signal that inhibits apoptosis E. Microglia is the term that identifies macrophages that reside in the liver 23. Select all that apply: which type of infection(s) is most likely to occur if the following molecules are defected: i) Rig-like receptor A. dsRNA bacteria B. dsRNA viruses C. dsDNA viruses D. ssDNA viruses E. dsDNA parasites iI) NK-kappaB A. Intracellular bacteria B. Parasites C. Gram-Positive bacteria D. dsRNA viruses E. Fungi iII) Type I interferons A. intracellular viruses B. extracellular bacteria C. extracellular parasites D. allergens E. extracellular viruses 24. Why do activated transcription factors need to undergo nuclear transportation during intracellular signalling? 25. Cytokines are both pleiotropic and redundant . Which definition aligns with pleiotropic and which one aligns with redundant? A. More than one cytokine induces the same effect (redundancy) B. All cytokines can contribute to inflammation C. One cytokine produces multiple effects (pleiotropy) D. Through evolution, certain cytokines have become less useful than others E. Many different cytokines can act on the same receptor

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

Winter 2022 – MIMM 214 Midterm Practice questions 4 26. Which of the following is incorrect regarding pathogen-recognition receptors (PRRs)? A. They are encoded in the germline B. They are randomly generated C. There is a finite number of these receptors D. They are the primary receptors expressed by leukocytes 27. Which of the following receptors is used to present antigen to T cells? A. Toll-like receptors (TLRs) B. Pathogen-recognition receptors (PRRs) C. Major histocompatibility complex (MHC) D. RIG-I-like receptors (RLRs) 28. Which of the following cytokines is involved in the induction of the acute phase response? A. IL-33 B. IFNg C. TNF-a D. TGF-b 29. A patient of yours has decreased blood volume and systemic infection and inflammation Based on what you learned in the class, what do you think is happening? 30. What are the differences between an immature and an activated DC? 31. What is the difference between plasmacytoid DCs and conventional DCs? 32. Regarding NK cells, identify which of the following statements are true (you may select more than one choice). A. They require priming (activation) since they are of lymphoid lineage B. Release cytotoxic granules C. Are involved in killing tumor cells D. Recognize viral antigens to kill infected cells E. Generally, act earlier than cytotoxic T-lymphocytes in the immune response 33. Which of the following statements are false regarding CD4 and CD8 co-receptors? A. Most mature T cells express one of these coreceptors on their surface. B. CD4 binds MHC class II molecules C. CD8 binds MHC class 1 molecules D. CD4+ T cells generally have a “helper” function while CD8+ T cells generally have a “cytotoxic” function E. CD4 exists as a dimer while CD4 exists as a single α helix. 34. True or false: CD4 or CD8 are the signaling modules of the TCR complex.

Winter 2022 – MIMM 214 Midterm Practice questions 5 35. Make a flowchart that places the following events in the correct order and list where each event occurs in the body. Some may occur at the same time. a. Complement activation b. T-cell activation and differentiation c. Recruitment of neutrophils to injured tissue d. TLR signaling e. Recruitment of T-cells to injured tissue f. Tissue injury g. Upregulation of costimulatory molecules h. Formation of memory lymphocytes 36. DCs enter the lymph node through: 37. Which of the followings is a mechanism of IFN-beta therapy in Multiple sclerosis? a. Preventing lymphocytes from exiting the lymph node b. Allows more T cells to enter the blood-brain barrier c. Vasodilating the blood-brain barrier d. Increase relapse 38. During Multiple Sclerosis, the immune cells would attack what? 39. What are the three signals involved in activating naïve T cells? 40. True or False, professional antigen-presenting cells are all nucleated cells? 41. The TCR complex includes what? 42. Which of the following is true regarding HLA complexes? a. Their gene loci span many chromosomes b. HLA-A presents antigen to CD8+ T-cells c. All HLA molecules have two transmembrane domains, one in each chain d. Each of us have 18 alleles of MHC molecules in total e. MHC class II requires a peptide + MHC class II ࠵? chain + ࠵? 2 microglobulin for stable expression 43. A 5-year-old patient has a rare mutation in TAP. List some possible consequences of this. 44. Why do we need the CD4 and CD8 Co-receptors? 45. Which of the following concerning antigen presentation is incorrect ? a. Both MHC class I and II molecules originate from the ER b. Calnexin is a chaperone used to stabilize MHC class I c. Exogenous antigens are degraded by the proteasome d. CD4 has a single chain transmembrane protein while CD8 is a heterodimer e. Both MHC molecules have constant and variable regions f. Antigens bind to the variable regions of MHC molecules

Winter 2022 – MIMM 214 Midterm Practice questions 6 46. A 12-year-old patient has a polymorphism that prevents HLA-DM from interacting with the MHC-Class II complex in ER-derived vesicles. What would be the most likely consequence of this? a. Increased antigen presentation due to removal of HLA-DM inhibition b. Overall upregulation of cytokine production c. Reduced ability to degrade exogenous antigens d. Decreased capacity to load proteasome-derived peptides onto MHC class II 47. Tapasin is important in what mechanism? 48. Which of the following is true ? A. Polymorphism means each individual has many copies of related genes B. HLA-DR, HLA-DQ, HLA-DP, HLA-DM, HLA-DOA, HLA-DOB are an example of polygeny C. Polygeny and polymorphism is the same thing D. Polygeny and polymorphism reduces the degree of variance in MHC expression 49. How is allorecognition different from MHC restriction? 50. How are phosphorylation and dephosphorylation different? 51. You vaccinate two mice from the same parents with antigen X and reconstitute their immune systems with APCs from various donors. Upon re-exposure to antigen X, you find that one of them can only mount an effective response when reconstituted with APCs expressing MHC a , while the other is responsive to both MHC a and MHC b -expressing APCs. What is the basis for this difference and what are the MHC genotypes of the two mice? 52. Select all: Which statement(s) are true? A. IL-2 cytokine can undergo an autocrine fashion B. IL-2Ralpha receptor is expressed at baseline C. IL-2 and IL-2Ralpha receptor are important for cell proliferation D. Lack of co-stimulation molecules can still activate T cell cells

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

Winter 2022 – MIMM 214 Midterm Practice questions 7 ANSWERS 1. Select all that apply. Which of the following is/are a primary lymphoid organ? A. Bone marrow B. Peyer’s patches C. Lymph node D. Thymus E. Spleen 2. Which lineage to NK cells belong to? Answer: Lymphoid lineage 3. Which cells are granulocytes? Answer: Neutrophiles, Basophils, Mast cells, Eosinophils 4. If your immune system attacks against self, that is known as: Answer: Autoimmunity 5. If your immune system attacks against safe, non-self, that is known as: Answer: Allergies 6. What is the difference between negative and clonal selection? Answer: - Negative selection: removal of autoreactive T/B cells - Clonal selection: Expansion of a T/B cell population following recognition of its cognate antigen 7. What is the primary cell type involved in humoral immunity? What is the name of the molecule secreted specifically by this cell-type? Answer: - B cells - Immunoglobulins/antibodies 8. What is a cytokine? A. A cell-surface receptor B. An intracellular transcription factor C. An enzyme D. A secreted messenger protein E. A specific region of an antigen 9. Adaptive immunity is mediated by which key cells: Answer: B and T lymphocytes

Winter 2022 – MIMM 214 Midterm Practice questions 8 10. True or false. The innate immune response improves with repeated exposure (i.e. infection or vaccination). A. True B. False 11. Which of the following statements is TRUE? a. All PRRs induce phagocytosis False receptors are involved in mediating phagocytosis, many of which are PRRs → but, not all PRRs induce phagocytosis! b. monocytes produce extracellular matrices called NETs to trap microorganisms as par tof the innate immune response false → neutrophils produce NETs!! c. CD47 is one of the most potent “eat me” signals, and is a common marker for apoptotic cells false → CD47 is a “don’t eat me” signal expressed by healthy erythrocytes (and cancer cells!) d. to cause inflammation, a pathogen must always breach one of the body’s barriers true → as said on slide 10 of lecture 3, infection (and subsequent inflammation) caused by a pathogen necessitates crossing one of the body’s barriers 1. note that sterile inflammation does exist, but to my knowledge, that’s distinct from inflammation caused by a pathogen, which requires that pathogen to breach a barrier 12. Why is human skin resistant to colonization by E. coli despite exposure to it? Answer: There are chemical barriers such as enzymes that digest some bacteria compared to others. 13. Select all: Which cells are involved in innate immunity? a. Neutrophils b. T cells c. Conventional DCs d. NKs e. Monocytes f. B cells 14. Select all: Which cells are phagocytic? a. Macrophages b. DCs c. B cells d. NK cells e. Neutrophils

Winter 2022 – MIMM 214 Midterm Practice questions 9 15. Name 3 key roles that the phagosome/phagolysosome plays in the immune response. Answer: pathogen killing or antigen degradation, pathogen/antigen processing, pathogen/antigen presentation 16. What is a NET? Answer: Neutrophil extracellular traps, produced by neutrophils. The neutrophil ruptures and the cytoplasm and all the cell content would be released. The NETs form these long filaments that trap microorganisms. 17. What would happen if we remove (knock-out) the genes that encode for the adhesion molecules on endothelial cells? Possible answer: immune cells would not be able to initiate interaction, reducing their ability to undergo diapedesis and migration to the site of infection. 18. In which tissue/organ are complement proteins mostly produced? A. Lymph node B. Spleen C. Liver D. Kidney E. Thymus 19. Which of the following complement proteins is an opsonin? A. C2a B. C3b C. C4b D. C3bBb 20. A patient has reduced levels of C3 convertase compared to a healthy individual with the same extracellular pathogen infection. You measure the levels of different complement proteins and notice that it has low levels of C3 convertase, normal levels of C1q, and low levels of Mannose-binding lectin. Based on these results, which component of the immune system is deficient in the patient? Answer: There is an issue with Lectin pathway, mainly producing MBLs. 21. Membrane-attack complex involves which two key complement proteins? Answer: C5 and C3 22. Which of the following statements is TRUE? A. Innate lymphoid cells (ILCs) are found primarily in circulation B. Cytokines are only produced by antigen-presenting cells (APCs) C. Type I interferon is induced following infection by extracellular bacterial pathogens

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

Winter 2022 – MIMM 214 Midterm Practice questions 10 D. CD47 provides a signal that inhibits apoptosis E. Microglia is the term that identifies macrophages that reside in the liver 23. Select all that apply: which type of infection(s) is most likely to occur if the following molecules are defected: i) Rig-like receptor A: dsRNA bacteria B: dsRNA viruses C: dsDNA viruses D: ssDNA viruses E: dsDNA parasites iI) NK-kappaB A: intracellular bacteria B: Parasites C: Gram-positive bacteria D: dsRNA viruses E: Fungi iII) Type I interferons A: intracellular viruses B: extracellular bacteria C: extracellular parasites D: allergens E: extracellular viruses 24. Why do activated transcription factors need to undergo nuclear transportation during intracellular signalling? Answer: To activate genes that encode for a functional response 25. Cytokines are both pleiotropic and redundant . Which definition aligns with pleiotropic and which one aligns with redundant? a. More than one cytokine induces the same effect (redundancy) b. All cytokines can contribute to inflammation c. One cytokine produces multiple effects (pleiotropy) d. Through evolution, certain cytokines have become less useful than others e. Many different cytokines can act on the same receptor 26. Which of the following is incorrect regarding pathogen-recognition receptors (PRRs)? A. They are encoded in the germline B. They are randomly generated C. There is a finite number of these receptors D. They are the primary receptors expressed by leukocytes

Winter 2022 – MIMM 214 Midterm Practice questions 11 27. Which of the following receptors is used to present antigen to T cells? A. Toll-like receptors (TLRs) B. Pathogen-recognition receptors (PRRs) C. Major histocompatibility complex (MHC) D. RIG-I-like receptors (RLRs) 28. Which of the following cytokines is involved in the induction of the acute phase response? A. IL-33 B. IFNg C. TNF-a D. TGF-b 29. A patient of yours has decreased blood volume and systemic infection and inflammation Based on what you learned in the class, what do you think is happening? Answer: Systemic TNF- a leads to systemic effects: migration of innate cells, dilated blood vessels and increases clotting. 30. What are the differences between an immature and an activated DC? Immature: many dendrites, highly phagocytic Activated: no longer phagocytic, no dendrites, expresses co-stimulatory molecules, can migrate to secondary lymphoid organ, expresses pMHC and interacts with T cells 31. What is the difference between plasmacytoid DCs and conventional DCs? Answer: Conventional: Travel to lymphoid tissue once activated, activates T cells and is the classic APC Plasmacytoid: Capable of producing large amounts of type I IFN, stays at site of infection, secretes cytokines and can amplify local response. 32. Regarding NK cells, identify which of the following statements are true (you may select more than one choice). a. They require priming (activation) since they are of lymphoid lineage b. Release cytotoxic granules c. Are involved in killing tumor cells d. Recognize viral antigens to kill infected cells e. Generally, act earlier than cytotoxic T-lymphocytes in the immune response NK cells do not require priming, unlike T-cells and B-cells, and target cells which are not expressing MHC Class I for death. Its cytotoxic activity does not involve direct recognition of viral antigens.

Winter 2022 – MIMM 214 Midterm Practice questions 12 33. Which of the following statements are false regarding CD4 and CD8 co-receptors? a. Most mature T cells express one of these coreceptors on their surface. b. CD4 binds MHC class II molecules c. CD8 binds MHC class 1 molecules d. CD4+ T cells generally have a “helper” function while CD8+ T cells generally have a “cytotoxic” function e. CD4 exists as a dimer while CD4 exists as a single α helix. 34. True or false: CD4 or CD8 are the signaling modules of the TCR complex. Answer: False. CD4 and CD8 are coreceptors for the TCR. CD3 and the TCR zeta chains form the signalling unit of the TCR complex. 35. Make a flowchart that places the following events in the correct order and list where each event occurs in the body. Some may occur at the same time. a. Complement activation b. T-cell activation and differentiation c. Recruitment of neutrophils to injured tissue d. TLR signaling e. Recruitment of T-cells to injured tissue f. Tissue injury g. Upregulation of costimulatory molecules h. Formation of memory lymphocytes Answer: The order goes as follows: f à a, d à c, g à b à e à h 36. DCs enter the lymph node through: Answer: Afferent lymphatic vessels 37. Which of the followings is a mechanism of IFN-beta therapy in Multiple sclerosis? a. Preventing lymphocytes from exiting the lymph node b. Allows more T cells to enter the blood-brain barrier c. Vasodilating the blood-brain barrier d. Increase relapse 38. During Multiple Sclerosis, the immune cells would attack what? Answer: myelin sheath of axons 39. What are the three signals involved in activating naïve T cells? Answer: Signal 1: TCR signaling with p:MHC I or II, Signal 2: CD28: CD80/86 (B7.1,7.2) and Signal 3: cytokine signaling 40. True or False, professional antigen-presenting cells are all nucleated cells?

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

Winter 2022 – MIMM 214 Midterm Practice questions 13 Answer: False, professional antigen-presenting cells are DC or macrophages that present MHC Class II and all nucleated cells only present MHC I 41. The TCR complex includes what? Answer: CD3, zeta chains, TCR and ITAM motifs 42. Which of the following is true regarding HLA complexes? f. Their gene loci span many chromosomes g. HLA-A presents antigen to CD8+ T-cells h. All HLA molecules have two transmembrane domains, one in each chain i. Each of us have 18 alleles of MHC molecules in total j. MHC class II requires a peptide + MHC class II ࠵? chain + ࠵? 2 microglobulin for stable expression 43. A 5-year-old patient has a rare mutation in TAP. List some possible consequences of this. Possible Answer: This patient can no longer translocate antigenic peptides from the cytosol to the ER to be loaded on MHC class I. Without peptide binding, the MHC cannot be stably expressed. Hence, we would expect to see no expression of MHC class I and increased susceptibility to viruses. 44. Which MHC molecule binds short peptides of 8-10 amino acids? Answer: MHC class I 45. Why do we need the CD4 and CD8 Co-receptors? Answer: the TCR: pMHC interaction is a rather low affinity interaction and so these receptors would stabilize this interaction 46. Which of the following concerning antigen presentation is incorrect ? a. Both MHC class I and II molecules originate from the ER b. Calnexin is a chaperone used to stabilize MHC class I c. Exogenous antigens are degraded by the proteasome d. CD4 has a single chain transmembrane protein while CD8 is a heterodimer e. Both MHC molecules have constant and variable regions f. Antigens bind to the variable regions of MHC molecules Exogenous antigens are taken into phagolysosomes and degraded by proteases upon acidification. The proteasome degrades endogenous peptides to be loaded on MHC class I. 47. A 12-year-old patient has a polymorphism that prevents HLA-DM from interacting with the MHC-Class II complex in ER-derived vesicles. What would be the most likely consequence of this? a. Increased antigen presentation due to removal of HLA-DM inhibition b. Overall upregulation of cytokine production c. Reduced ability to degrade exogenous antigens d. Decreased capacity to load proteasome-derived peptides onto MHC class II e. Expression of CLIP-MHC class II on the surface of APCs

Winter 2022 – MIMM 214 Midterm Practice questions 14 HLA-DM functions to release CLIP from MHC-class II, allowing exogenous peptides to bind upon vesicle fusion with the phagolysosome. Without it, CLIP will remain on the MHC as it is sent to the cell surface. HLA-DM does not inhibit antigen presentation or play a role in exogenous antigen degradation. Cytokine production would be reduced, since the CLIP-MHCs would be incapable of activating CD4 T cells during infection. Peptides loaded onto MHC class II are not derived from the proteasome. 48. Tapasin is important in what mechanism? Answer: Endogenous pathway, involved in binding partly folded MHC I to TAP 49. Which of the following is true ? A. Polymorphism means each individual has many copies of related genes B. HLA-DR, HLA-DQ, HLA-DP, HLA-DM, HLA-DOA, HLA-DOB are an example of polygeny C. Polygeny and polymorphism is the same thing D. Polygeny and polymorphism reduces the degree of variance in MHC expression 50. How is allorecognition different from MHC restriction? Answer: MHC restriction means that a give T cell is able to recognize a specific peptide only when bound to a specific SELF-MHC molecule. Allorecognition is the recognition by some T cells in the body of non-self MHC. 51. How are phosphorylation and dephosphorylation different? Answer: phosphorylation adds a phosphate group (activation) to a protein and dephosphorylation removes a phosphate group (inhibits signaling) 52. You vaccinate two mice from the same parents with antigen X and reconstitute their immune systems with APCs from various donors. Upon re-exposure to antigen X, you find that one of them can only mount an effective response when reconstituted with APCs expressing MHC a , while the other is responsive to both MHC a and MHC b -expressing APCs. What is the basis for this difference and what are the MHC genotypes of the two mice? Answer: The genotypes of the mice would be MHC a / MHC a and MHC a /MHC b . The homozygous mouse would only be able to respond to MHC a -expressing APCs, due to MHC restriction of T-cells. 53. Select all: Which statement(s) are true? A. IL-2 cytokine can undergo an autocrine fashion B. IL-2Ralpha receptor is expressed at baseline C. IL-2 and IL-2Ralpha receptor are important for cell proliferation D. Lack of co-stimulation molecules can still activate T cell cells

MIMM 214 - Practice midterm questions

Related Documents