Cell-Mediated & Humoral Responses MCQ Quiz | Immunology

Welcome to this specialized quiz on Cell-Mediated and Humoral Immunity, designed for MBBS students. This quiz will test your understanding of the intricate mechanisms by which the adaptive immune system recognizes and eliminates pathogens. You will encounter 25 multiple-choice questions covering key topics such as T-cell and B-cell activation, MHC presentation, antibody functions, cytotoxic T-lymphocyte activity, and the roles of various cytokines and helper T-cell subsets. This is an excellent opportunity to reinforce your knowledge and prepare for your examinations. After submitting your answers, you’ll see your score and a detailed review of each question. You can also download a PDF copy of all questions with their correct answers for future revision.

1. Which of the following protein complexes is primarily responsible for presenting endogenous antigens, such as viral proteins, to CD8+ T cells?

2. Exogenous antigens, such as bacteria phagocytosed by a macrophage, are processed and presented on the cell surface by:

3. The second signal required for T-cell activation, which provides co-stimulation and prevents anergy, is primarily mediated by the interaction between:

4. The primary cell type responsible for producing and secreting antibodies during a humoral immune response is the:

5. Which antibody isotype is the first to be produced during a primary immune response and exists as a pentamer?

6. The principal effector cell of cell-mediated immunity that directly kills virus-infected cells and tumor cells is the:

7. Cytotoxic T lymphocytes induce apoptosis in target cells primarily through the release of which two molecules?

8. A T helper cell that secretes IFN-γ and is crucial for activating macrophages to kill intracellular pathogens is characteristic of which subset?

9. The process by which antibodies, particularly IgG, coat a pathogen to enhance its phagocytosis is known as:

10. T-cell dependent B-cell activation requires a crucial interaction for class switching and memory B-cell formation. This interaction is between:

11. Compared to a primary immune response, a secondary (anamnestic) response is characterized by:

12. The process that leads to an increased affinity of antibodies for their antigen during the course of a humoral response is known as:

13. Which antibody class is primarily responsible for providing mucosal immunity by being secreted into the lumen of the gastrointestinal and respiratory tracts?

14. Antibody-dependent cell-mediated cytotoxicity (ADCC) is a mechanism where Fc receptors on an effector cell bind to antibodies attached to a target cell. A classic example involves:

15. T-independent antigens, such as bacterial lipopolysaccharide (LPS), can activate B cells without T-cell help. The response to these antigens typically results in the production of:

16. A Th2-dominant immune response, characterized by the secretion of IL-4, IL-5, and IL-13, is most effective against:

17. Which subset of CD4+ T cells is primarily involved in immune suppression and maintaining self-tolerance, often by producing TGF-β and IL-10?

18. Which of the following cells is considered the most potent professional antigen-presenting cell (APC) for activating naive T cells?

19. The cytokine primarily responsible for the proliferation and survival of activated T cells, acting in an autocrine and paracrine manner, is:

20. A lymphocyte that matures in the thymus and expresses a T-cell receptor (TCR), CD3, and either CD4 or CD8 is a:

21. Central tolerance for T cells, involving the elimination of self-reactive thymocytes through negative selection, occurs in which organ?

22. The region of an antibody molecule responsible for binding to a specific antigen epitope is the:

23. Which two antibody isotypes are most effective at activating the classical pathway of the complement system?

24. Besides the perforin/granzyme system, CTLs can induce apoptosis in target cells through another major pathway involving the interaction of:

25. T follicular helper (Tfh) cells are specialized in providing help to B cells within the germinal centers of lymph nodes, a process essential for: