Micro Immunity To Infx And Mycololgy
- 1.
Which is(are) the effector cell(s) involved in ADCC? (More than 1 answer)
- A.
Macrophage
- B.
Neutrophil
- C.
NK cell
- D.
B lymphocyte
- E.
CD8+ T lymphocyte
Correct Answer(s)
A. MacropHage
B. NeutropHil
C. NK cellExplanation
Macrophages, neutrophils, and NK cells are all effector cells involved in antibody-dependent cellular cytotoxicity (ADCC). ADCC is a process in which antibodies bind to target cells, marking them for destruction. These effector cells recognize the antibodies bound to the target cells and release cytotoxic molecules to kill the target cells. B lymphocytes and CD8+ T lymphocytes are not typically involved in ADCC as they primarily function in antibody production and cell-mediated cytotoxicity, respectively.Rate this question:
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- 2.
3.2) Which of the following factors involved in antigen presentation are required for the initiation of a protective cell-mediated response?
- A.
MHC class I antigen presentation, CD86 co-stimulation and IL-12
- B.
MHC class II antigen presentation, CD86 co-stimulation and IL-12
- C.
MHC class I antigen presentation, CD86 co-stimulation and IL-4
- D.
MHC class II antigen presentation, CD86 co-stimulation and IL-4
- E.
MHC class I antigen presentation, CD40 co-stimulation and IL-12
- F.
MHC class II antigen presentation, CD40 co-stimulation and IL-12
- G.
MHC class I antigen presentation, CD40 co-stimulation and IL-4
- H.
MHC class II antigen presentation, CD40 co-stimulation and IL-4
Correct Answer
A. MHC class I antigen presentation, CD86 co-stimulation and IL-12Explanation
MHC class I antigen presentation, CD86 co-stimulation, and IL-12 are required for the initiation of a protective cell-mediated response. MHC class I antigen presentation allows the presentation of intracellular antigens to CD8+ T cells, which are important for cell-mediated immunity. CD86 co-stimulation provides a second signal to T cells, enhancing their activation and proliferation. IL-12 is a cytokine that promotes the differentiation of CD4+ T cells into Th1 cells, which are crucial for cell-mediated immune responses. Therefore, the combination of MHC class I antigen presentation, CD86 co-stimulation, and IL-12 is necessary for the initiation of a protective cell-mediated response.Rate this question:
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- 3.
Antibody-dependent cell cytoxicity (ADCC) relies on which antibody class?
- A.
IgA
- B.
IgD
- C.
IgE
- D.
IgG
- E.
IgM
Correct Answer
D. IgGExplanation
ADCC relies on the antibody class IgG because IgG antibodies have the ability to bind to target cells and recruit immune cells, such as natural killer cells, to destroy the target cells. This process is mediated by the Fc region of the IgG antibody, which interacts with Fc receptors on immune cells. IgA, IgD, IgE, and IgM do not play a significant role in ADCC.Rate this question:
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- 4.
Which antibody/effector cell tandem is specific for metazoan parasites?
- A.
IgM/eosinophil
- B.
IgG/basophil
- C.
IgA/NK cell
- D.
IgE/mast cell
- E.
IgA/macrophage
Correct Answer
D. IgE/mast cellExplanation
IgE is an antibody that is specifically involved in allergic reactions and immune responses against parasites. Mast cells are effector cells that are found in tissues and release inflammatory mediators in response to the binding of IgE antibodies to their surface receptors. This antibody/effector cell tandem is therefore specific for metazoan parasites, making IgE/mast cell the correct answer.Rate this question:
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- 5.
Which of the following receptors of phagocytic cells recognizes DNA viruses?
- A.
TLR-1
- B.
TLR-2
- C.
TLR-3
- D.
TLR-7
- E.
TLR-9
Correct Answer
E. TLR-9Explanation
TLR-9 is the correct answer because it is a toll-like receptor that recognizes DNA viruses. Toll-like receptors are a type of pattern recognition receptor that play a crucial role in the innate immune response by recognizing specific patterns on pathogens. TLR-9 specifically recognizes unmethylated CpG motifs that are commonly found in DNA viruses. This recognition triggers a signaling cascade that leads to the activation of phagocytic cells and the production of pro-inflammatory cytokines, ultimately helping to eliminate the viral infection.Rate this question:
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- 6.
What are the main events required for CD4 T lymphocyte activation against extracellular pathogens? (More than 1 answer)
- A.
Antigen presentation by dendritic cells & IL-12 production by macrophages
- B.
Antigen presentation by dendritic cells & IL-4 production by basophils
- C.
Antigen presentation by dendritic cells & IL-17 production by IL-6 and TGF-B
- D.
Antigen presentation by dendritic cells & IL-10 production by macrophages
- E.
Antigen presentation by dendritic cells & IL-6 production by macrophages
Correct Answer(s)
B. Antigen presentation by dendritic cells & IL-4 production by basopHils
C. Antigen presentation by dendritic cells & IL-17 production by IL-6 and TGF-BExplanation
CD4 T lymphocyte activation against extracellular pathogens requires antigen presentation by dendritic cells, which allows the T cells to recognize the pathogen. Additionally, IL-4 production by basophils and IL-17 production by IL-6 and TGF-B are also required for the activation of CD4 T lymphocytes. These cytokines play important roles in regulating the immune response and promoting the activation and differentiation of T cells.Rate this question:
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- 7.
3.1) Most commonly, the intracellular parasite Trypanosoma cruzi gains entry through the conjunctiva of the eye of a person rubbing reduviid bug feces and urine, laden with trypanosomes, into the eye following the insect’s blood meal. During the local inflammatory response that follows, some of the parasites are phagocytosed and processed by dendritic cells which then migrate to the pre-auricular lymph node to present trypanosome-derived antigen to naïve CD4 T lymphocytes. Which of the following factors involved in antigen presentation are required for the initiation of a protective TH1 response?
- A.
MHC class I antigen presentation, CD86 co-stimulation and IL-12
- B.
MHC class II antigen presentation, CD86 co-stimulation and IL-12
- C.
MHC class I antigen presentation, CD86 co-stimulation and IL-4
- D.
MHC class II antigen presentation, CD86 co-stimulation and IL-4
- E.
MHC class I antigen presentation, CD40 co-stimulation and IL-12
- F.
MHC class II antigen presentation, CD40 co-stimulation and IL-12
- G.
MHC class I antigen presentation, CD40 co-stimulation and IL-4
- H.
MHC class II antigen presentation, CD40 co-stimulation and IL-4
Correct Answer
B. MHC class II antigen presentation, CD86 co-stimulation and IL-12Explanation
The difference between questions 2 and 3 is the level of detail. CD4+ T lymphocyte activation requires Ag presentation (which is done by an APC) and cytokine stimulation. Remember however that efficient Ag presentation by APCs also requires two signals: MHC class II antigen presentation and CD86 co-stimulation. So CD4+ T lymphocyte activation actually requires 3 signals: MHC class II Ag presentation, co-stimulation and cytokine stimulation. Therefore, question 2 implies that, during Ag presentation by dendritic cells, both MHC class II Ag presentation and co-stimulation have occurred.Rate this question:
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- 8.
Which of the following receptors of phagocytic cells recognizes LPS?
- A.
TLR-5
- B.
TLR-4
- C.
TLR-1
- D.
TLR-2
- E.
TLR-3
- F.
TLR-6
- G.
TLR-7
- H.
TLR-8
- I.
TLR-9
- J.
TLR-10
Correct Answer
B. TLR-4Explanation
TLR-4 is the correct answer because it is the receptor of phagocytic cells that recognizes LPS (lipopolysaccharide). LPS is a component of the outer membrane of gram-negative bacteria and is recognized by TLR-4, leading to the activation of the immune response and the initiation of an inflammatory reaction. TLR-4 is expressed on the surface of macrophages, dendritic cells, and other phagocytic cells, allowing them to detect and respond to bacterial infections.Rate this question:
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- 9.
Which of the following are not sensitive to the complement-activated membrane attack complex?
- A.
Naked viruses
- B.
Enveloped viruses
- C.
Fungi
- D.
Helminths
Correct Answer
A. Naked virusesExplanation
Naked viruses are not sensitive to the complement-activated membrane attack complex. This is because naked viruses lack an envelope, which is a lipid bilayer that is susceptible to disruption by the membrane attack complex. Therefore, naked viruses are able to evade the immune response mediated by the complement system. In contrast, enveloped viruses have a lipid envelope that can be targeted and destroyed by the membrane attack complex. Fungi and helminths, which are not viruses, are also not sensitive to the membrane attack complex.Rate this question:
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- 10.
What are the cells responsible for secreting IFN-y during a TH1 response?
- A.
Macrophages, NK cells & eosinophils
- B.
NK cells, CD4+ T lymphocytes & CD8+ T lymphocytes
- C.
Macrophages, CD4+ T lymphocytes & dendritic cells
- D.
Dendritic cells, CD4+ T lymphocytes & CD8+ T lymphocytes
Correct Answer
B. NK cells, CD4+ T lympHocytes & CD8+ T lympHocytesExplanation
The cells responsible for secreting IFN-y during a TH1 response are NK cells, CD4+ T lymphocytes, and CD8+ T lymphocytes. These cells play a crucial role in the immune response by producing IFN-y, which is a key cytokine involved in the activation of macrophages and the elimination of intracellular pathogens. Macrophages and dendritic cells also play important roles in the immune response, but they are not the primary cells responsible for secreting IFN-y during a TH1 response. Eosinophils are typically associated with allergic responses and are not major producers of IFN-y.Rate this question:
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- 11.
What are the cells responsible for secreting IL-4 during a TH2 response?
- A.
Macrophages & CD8+ T lymphocytes
- B.
NK cells & CD4+ T lymphocytes
- C.
Basophils & CD4+ T lymphocytes
- D.
CD4+ T lymphocytes & CD8+ T lymphocytes
Correct Answer
C. BasopHils & CD4+ T lympHocytesExplanation
Basophils and CD4+ T lymphocytes are the cells responsible for secreting IL-4 during a TH2 response. Basophils are a type of white blood cell that play a role in allergic reactions and release IL-4 to promote the differentiation of CD4+ T lymphocytes into TH2 cells. CD4+ T lymphocytes, also known as helper T cells, are a type of immune cell that release IL-4 to stimulate the production of antibodies and activate other immune cells during a TH2 response. Therefore, the correct answer is Basophils & CD4+ T lymphocytes.Rate this question:
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- 12.
What you expect to see in a PAS stained microscopic section from a lung biopsy of disseminated infection with Blastomyces dermatitidis?
- A.
Tiny red rods with no nuclear membrane
- B.
Purple diplococci seen only well on oil immersion.
- C.
Budding ovals stained hot pink red.
- D.
Dark gray filaments with little branching
- E.
Flagellated cells with prominent nuclei staining blue
Correct Answer
C. Budding ovals stained hot pink red.Explanation
First you needed to recognize Blastomyces as the name of a dimorphic fungus and then remember what form the fungus would take in the body (yeast) and then to remember that fungi on a PAS will show up as hot pink-red color so the answer is the third choice.Rate this question:
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- 13.
A new pathogen is found. Which of the following compounds would suggest that the agent is a fungus?
- A.
Peptidoglycan
- B.
Teichoic acid
- C.
Endotoxin
- D.
Chlorophyll
- E.
Ergosterol
Correct Answer
E. ErgosterolExplanation
Ergosterol is the dominant sterol in the fungal membranes. Peptidoglycan and teichoic acids are unique to bacteria. Gram negative bacteria have endotoxin. A few fungi or endotoxin-like compounds. Fungi are heterotrophic, deriving their nutrition from organic compounds so are not photosynthetic so do not have chlorophyll.Rate this question:
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- 14.
An auto mechanic in NJ develops Valley Fever caused by Coccidioides immitis even though he has never been to the endemic area in SE US. He does remember changing the oil on a car from California a few weeks ago. You have seen the slides of the organism from his lungs. If you are one of House, MD’s residents and you had to go out to the California car (with a fitted respirator mask on for safety) and get sand out of the bottom of the car and look for the fungus under the microscope back in the lab, what would you be looking for?
- A.
A form that look just like the forms in the lung
- B.
A yeast or yeast like form
- C.
A mold maybe with some type of spores
Correct Answer
C. A mold maybe with some type of sporesExplanation
Coccioides is a dimorphic fungus. This means it has filamentous forms and spores found in nature and the more yeast-like form (Although in Coccidioides it is not actually yeast but single cells round cells inside a spherule) found in the lungs. (You’ll learn what it looks like later.) So the correct answer is C. (Remember “mold” is the name for hyphal forms.)Rate this question:
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Current Version
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Mar 20, 2023Quiz Edited by
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Jun 07, 2012Quiz Created by
Chachelly
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