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4.3 Cell-Mediated Immunity β Test 1
Q1. Cell-mediated immunity is carried out mainly by:β T lymphocytes
Q2. Cytotoxic CD8βΊ T cells recognise antigen presented on:β MHC class I molecules
Q3. Helper CD4βΊ T cells recognise antigen presented on:β MHC class II molecules
Q4. Cytotoxic T cells kill target cells primarily by:β Releasing perforin and granzymes to trigger apoptosis
Q5. Th1 cells promote cell-mediated immunity chiefly by secreting:β IFN-Ξ³ to activate macrophages
Q6. Delayed-type hypersensitivity (DTH), e.g. the tuberculin reaction, is mediated by:β CD4βΊ Th1 cells and activated macrophages
Q7. The 'two-signal' requirement for naive T-cell activation means the T cell needs:β PeptideβMHC (signal 1) plus co-stimulation (signal 2)
Q8. Natural killer (NK) cells contribute to cell-mediated defence by:β Killing cells that have lost MHC class I ('missing self')
Q9. Macrophage activation in cell-mediated immunity is driven principally by:β IFN-Ξ³ from Th1 cells
Q10. MHC restriction means that a T cell recognises:β Antigenic peptide only in association with self-MHC
Q11. The transcription factor that defines and drives regulatory T (Treg) cells is:β FoxP3
Q12. Which subset is most important for help in both humoral and cell-mediated immunity?β CD4βΊ helper T cells
Q13. The first signal in T-cell activation is delivered through the:β T-cell receptor recognising peptideβMHC
Q14. Cytotoxic T cells are especially important for defence against:β Intracellular viruses and tumour cells
Q15. Anergy in a T cell refers to:β Functional unresponsiveness after signal 1 without co-stimulation
Q16. Th17 cells, a CD4βΊ subset, are characterised by production of:β IL-17 and defence at mucosal/epithelial barriers
Q17. Graft rejection is predominantly mediated by:β T-cell-mediated (cellular) immunity
Q18. The co-stimulatory signal for T cells is typically provided by:β B7 (CD80/CD86) on the APC engaging CD28 on the T cell
Q19. A patient with severely reduced CD4βΊ T cells (as in advanced HIV) shows:β Impaired both humoral and cell-mediated responses
Q20. Activated T cells can produce which of the following?β Cytokines including interferons and TNF
Q21. The helper T (TH) cell functions to:β Activate both B cells and cytotoxic T cells
Q22. Cytotoxic T cells are effective against:β Virus-infected cells, and contribute in allergy and autoimmunity
Q23. A person makes antibodies against bacteria but not against viruses. Which cells are likely defective?β T cells (needed for help against many viruses)
Q24. Which cells destroy virally infected cells in cell-mediated immunity?β Cytotoxic T cells (CD8)
Q25. How do effector B cells differ from cytotoxic T cells?β B cells secrete antibody to fight pathogens; cytotoxic T cells directly kill infected cells
Q26. For antigen-activated effector T cells, which statements are correct? P: CD4βΊ cells help macrophages; Q: CD4βΊ cells help B cells become plasma cells; R: CD8βΊ cells help B cells become plasma cells; S: CD8βΊ cells kill virus-infected cells.β P, Q and S only
Q27. Match each T-cell type with its principal function and select the correct option.β A-iii, B-i, C-iv, D-ii