Q.1 Which of the following is the primary immune system cell responsible for killing tumor cells directly?
B cells
CD8+ T cells
Helper T cells
Macrophages
Explanation - CD8+ cytotoxic T cells recognize tumor-associated antigens presented on MHC class I molecules and directly kill tumor cells.
Correct answer is: CD8+ T cells
Q.2 What type of antigens are commonly expressed on tumor cells and can trigger immune responses?
Self-antigens
Tumor-associated antigens
Blood group antigens
Microbial antigens
Explanation - Tumor-associated antigens are expressed on tumor cells and may also be found at low levels on normal cells, but at higher levels or abnormal contexts in tumors.
Correct answer is: Tumor-associated antigens
Q.3 Natural Killer (NK) cells target tumor cells primarily when:
MHC class I is absent or reduced
MHC class II is highly expressed
Antibodies are bound to bacteria
Complement proteins are active
Explanation - NK cells recognize and kill tumor cells that have downregulated MHC class I molecules, a common immune evasion strategy by tumors.
Correct answer is: MHC class I is absent or reduced
Q.4 Which cytokine is most important in enhancing cytotoxic T cell responses against tumors?
IL-4
IL-10
IL-2
IL-6
Explanation - IL-2 is a key growth factor for T lymphocytes, enhancing their proliferation and cytotoxic activity against tumor cells.
Correct answer is: IL-2
Q.5 What is immunoediting in tumor immunology?
The mutation of immune cells by tumors
The process by which immunity suppresses or shapes tumor growth
Editing tumor DNA directly
Antibody modification during immune response
Explanation - Immunoediting refers to the dynamic process involving elimination, equilibrium, and escape, through which the immune system interacts with developing tumors.
Correct answer is: The process by which immunity suppresses or shapes tumor growth
Q.6 The PD-1/PD-L1 pathway is significant in tumor immunology because:
It enhances tumor antigen presentation
It promotes apoptosis of tumor cells
It suppresses T cell activity
It increases antibody production
Explanation - The PD-1 receptor on T cells interacts with PD-L1 on tumor cells, leading to inhibition of T cell function and tumor immune evasion.
Correct answer is: It suppresses T cell activity
Q.7 Which immune cell type is most associated with antibody-dependent cellular cytotoxicity (ADCC) against tumor cells?
Neutrophils
NK cells
Helper T cells
Basophils
Explanation - NK cells recognize antibody-coated tumor cells through Fc receptors and mediate ADCC.
Correct answer is: NK cells
Q.8 What is the function of tumor suppressor genes in cancer?
Promote uncontrolled cell growth
Repair DNA and regulate cell cycle
Enhance angiogenesis
Stimulate immune evasion
Explanation - Tumor suppressor genes prevent uncontrolled proliferation by regulating cell cycle checkpoints and DNA repair.
Correct answer is: Repair DNA and regulate cell cycle
Q.9 Which of the following is an example of a tumor-specific antigen?
Alpha-fetoprotein
HER2/neu
p53 mutation
Carcinoembryonic antigen
Explanation - Mutated p53 is considered a tumor-specific antigen because it is only expressed in tumor cells, unlike other oncofetal antigens.
Correct answer is: p53 mutation
Q.10 Checkpoint inhibitor drugs like ipilimumab work by blocking:
CTLA-4
MHC class I
CD28
IL-1 receptor
Explanation - Ipilimumab blocks CTLA-4, an inhibitory receptor on T cells, thereby enhancing anti-tumor immune responses.
Correct answer is: CTLA-4
Q.11 Tumors often evade immune surveillance by secreting which immunosuppressive cytokine?
IL-12
IL-2
TGF-beta
IFN-gamma
Explanation - TGF-beta suppresses T cell and NK cell activity, facilitating tumor immune evasion.
Correct answer is: TGF-beta
Q.12 Monoclonal antibody therapies against tumors work by:
Neutralizing tumor DNA
Activating innate immunity only
Targeting tumor antigens for immune destruction
Enhancing angiogenesis
Explanation - Monoclonal antibodies bind to tumor-associated antigens, facilitating immune recognition and destruction.
Correct answer is: Targeting tumor antigens for immune destruction
Q.13 What is the equilibrium phase in cancer immunoediting?
Tumor completely eliminated
Tumor grows unchecked
Immune system controls tumor without eliminating it
Tumor hides from immune recognition
Explanation - During equilibrium, tumor cells persist but are kept in check by immune responses, without complete elimination.
Correct answer is: Immune system controls tumor without eliminating it
Q.14 Which immune checkpoint pathway has been targeted by drugs such as nivolumab and pembrolizumab?
CD28/B7
PD-1/PD-L1
MHC/TCR
IL-2/IL-2R
Explanation - Nivolumab and pembrolizumab block PD-1 signaling, preventing tumor-mediated T cell inhibition.
Correct answer is: PD-1/PD-L1
Q.15 Dendritic cells fight tumors by:
Directly lysing tumor cells
Producing antibodies
Presenting tumor antigens to T cells
Enhancing angiogenesis
Explanation - Dendritic cells are potent antigen-presenting cells, critical for initiating anti-tumor T cell responses.
Correct answer is: Presenting tumor antigens to T cells
Q.16 Which tumor marker is commonly elevated in liver cancer?
Carcinoembryonic antigen
Alpha-fetoprotein
CA-125
PSA
Explanation - Alpha-fetoprotein (AFP) is a fetal protein re-expressed in hepatocellular carcinoma and used as a tumor marker.
Correct answer is: Alpha-fetoprotein
Q.17 Which immune cells are known as 'tumor-associated macrophages' (TAMs)?
Macrophages promoting anti-tumor activity
Macrophages that infiltrate tumors and often support tumor growth
Macrophages from bone marrow only
NK cell precursors
Explanation - TAMs are macrophages within tumors that frequently promote angiogenesis, suppress immunity, and aid tumor progression.
Correct answer is: Macrophages that infiltrate tumors and often support tumor growth
Q.18 Which immune process can enhance tumor growth by selecting for less immunogenic variants?
Complement activation
Immunoediting
Apoptosis
Clonal expansion
Explanation - Immunoediting removes immunogenic tumor cells while selecting for variants that evade immunity, contributing to tumor progression.
Correct answer is: Immunoediting
Q.19 Oncofetal antigens such as CEA are useful in tumor immunology because:
They are tumor-specific markers
They are normally present only in embryos but re-expressed in tumors
They are found in all normal adult cells
They stimulate angiogenesis
Explanation - Oncofetal antigens like carcinoembryonic antigen (CEA) reappear in tumors, making them useful biomarkers.
Correct answer is: They are normally present only in embryos but re-expressed in tumors
Q.20 Which immune therapy involves the transfer of patient’s own modified T cells back into the body to fight tumors?
Monoclonal antibody therapy
CAR-T cell therapy
Cytokine therapy
Checkpoint blockade
Explanation - CAR-T cell therapy modifies patient’s T cells with chimeric antigen receptors to target tumor antigens.
Correct answer is: CAR-T cell therapy
Q.21 How does IFN-gamma contribute to tumor immunity?
Suppresses macrophages
Downregulates MHC expression
Activates macrophages and enhances antigen presentation
Inhibits cytotoxic T cells
Explanation - IFN-gamma enhances immune surveillance by activating macrophages and increasing MHC expression on tumor cells.
Correct answer is: Activates macrophages and enhances antigen presentation
Q.22 Which process is crucial for tumors to establish blood supply for growth and metastasis?
Apoptosis
Necrosis
Angiogenesis
Phagocytosis
Explanation - Angiogenesis allows tumors to develop new blood vessels, providing nutrients and pathways for metastasis.
Correct answer is: Angiogenesis
Q.23 Which immune component is critical for recognizing tumor cells expressing abnormal peptides on MHC class I molecules?
CD4+ T cells
B cells
CD8+ T cells
Neutrophils
Explanation - CD8+ cytotoxic T cells recognize tumor peptides presented by MHC class I molecules and induce cell death.
Correct answer is: CD8+ T cells
Q.24 Which viral infection is strongly linked to the development of cervical cancer?
HIV
Hepatitis B
Human papillomavirus
Epstein-Barr virus
Explanation - Human papillomavirus (HPV) infection, especially with high-risk strains, is a major cause of cervical cancer.
Correct answer is: Human papillomavirus
Q.25 The 'escape' phase of immunoediting is characterized by:
Tumor dormancy
Immune-mediated tumor clearance
Tumor variants evading immune detection and growing progressively
Activation of NK cells
Explanation - In the escape phase, tumors acquire mutations or mechanisms that allow them to evade immune control and expand.
Correct answer is: Tumor variants evading immune detection and growing progressively