Immunotherapeutics and antibody humanisation MCQs With Answer

Introduction: Immunotherapeutics and antibody humanisation MCQs With Answer is a focused quiz set designed for M.Pharm students studying Cellular and Molecular Pharmacology. This collection reinforces advanced concepts such as antibody structure, mechanisms of action (ADCC, CDC), antibody engineering strategies (chimeric, humanized, fully human), phage display, transgenic platforms, Fc engineering, glycoengineering, immunogenicity mitigation, and applications like ADCs and bispecific antibodies. Each question challenges conceptual understanding and practical implications in drug development and therapeutic design. Answers are provided for self-assessment. Use these MCQs to deepen your comprehension, prepare for exams, and link molecular strategies to clinical pharmacology and biotherapeutic optimization.

Q1. Which region of an antibody is primarily modified during CDR grafting to reduce immunogenicity while retaining antigen specificity?

• Fc region
• Heavy-chain constant region
• Complementarity-determining regions (CDRs) grafted onto human frameworks
• Hinge region

Correct Answer: Complementarity-determining regions (CDRs) grafted onto human frameworks

Q2. What is the principal rationale for humanising a murine monoclonal antibody?

• To increase its molecular weight
• To reduce human anti-mouse antibody (HAMA) responses and immunogenicity in patients
• To enable easier purification by protein A chromatography
• To increase complement activation irrespective of clinical need

Correct Answer: To reduce human anti-mouse antibody (HAMA) responses and immunogenicity in patients

Q3. Which technique is most commonly used to generate fully human antibodies without using human donors?

• Hybridoma production from mouse spleen
• Phage display library screening
• Direct cloning of murine VH and VL
• PEGylation of murine IgG

Correct Answer: Phage display library screening

Q4. Which Fc modification is used to extend antibody serum half-life by enhancing FcRn binding at acidic pH?

• Afucosylation of Fc glycans
• LS (M428L/N434S) or YTE (M252Y/S254T/T256E) mutations in Fc
• Cleavage of the hinge region
• Substitution of IgG to IgM isotype

Correct Answer: LS (M428L/N434S) or YTE (M252Y/S254T/T256E) mutations in Fc

Q5. Which IgG subclass is generally most effective at mediating antibody-dependent cellular cytotoxicity (ADCC)?

• IgG1
• IgG2
• IgG3
• IgG4

Correct Answer: IgG1

Q6. Afucosylated antibodies show enhanced ADCC because fucose removal increases affinity for which receptor?

• FcRn
• FcγRIIIa (CD16a)
• C1q
• IL-2 receptor

Correct Answer: FcγRIIIa (CD16a)

Q7. Which strategy directly reduces antigen-binding immunogenic T-cell epitopes in therapeutic antibodies?

• CDR grafting without framework optimization
• Computational de-immunization (epitope removal/mutation)
• Increasing antibody glycosylation heterogeneity
• Switching constant region subclasses

Correct Answer: Computational de-immunization (epitope removal/mutation)

Q8. Bispecific antibodies are designed primarily to:

• Increase the FcRn-mediated recycling only
• Bind two different antigens or epitopes simultaneously
• Enhance complement activation exclusively
• Reduce molecular size to below 30 kDa

Correct Answer: Bind two different antigens or epitopes simultaneously

Q9. Antibody–drug conjugates (ADCs) require careful linker design because:

• Linkers must avoid releasing payload inside target cells
• Linker stability affects therapeutic index, controlling circulation stability and intracellular release
• Linkers are required to increase immunogenicity
• Long linkers always decrease potency

Correct Answer: Linker stability affects therapeutic index, controlling circulation stability and intracellular release

Q10. Which of the following is a major cause of reduced efficacy and adverse reactions to therapeutic antibodies in patients?

• Formation of anti-drug antibodies (ADAs)
• Excessive FcRn-mediated recycling
• Overabundance of IgG4 subclass in formulation
• Use of fully human antibodies only

Correct Answer: Formation of anti-drug antibodies (ADAs)

Q11. Which method is most suitable for identifying framework residues essential for maintaining CDR conformation during humanisation?

• Random chemical mutagenesis
• Structural modelling and backmutation guided by crystal structures or homology models
• Replacing entire VH and VL with human sequences wholesale
• Glycan profiling

Correct Answer: Structural modelling and backmutation guided by crystal structures or homology models

Q12. Checkpoint inhibitor antibodies (e.g., anti-PD-1) exert their therapeutic effect primarily by:

• Directly killing tumour cells via CDC
• Blocking inhibitory signals to reinvigorate T-cell responses
• Neutralizing circulating growth factors
• Delivering cytotoxic payloads to tumours

Correct Answer: Blocking inhibitory signals to reinvigorate T-cell responses

Q13. Which property of the Fc domain is important for complement-dependent cytotoxicity (CDC)?

• The presence and accessibility of C1q-binding sites in IgG Fc
• Affinity for FcRn at neutral pH
• Glycosylation at the Fab region
• The isoelectric point of the variable region

Correct Answer: The presence and accessibility of C1q-binding sites in IgG Fc

Q14. Transgenic mice engineered to produce human antibodies are primarily used to:

• Produce high-fucose murine IgG
• Generate fully human monoclonal antibodies via immunization
• Increase murine immunogenicity in humans
• Replace the need for Fc engineering

Correct Answer: Generate fully human monoclonal antibodies via immunization

Q15. Which analytical assay is commonly used to detect and quantify anti-drug antibodies (ADAs) in patients?

• ELISA or bridging immunoassay formats
• Mass spectrometry of whole blood without enrichment
• Western blot for cytokine detection
• Protein A chromatography profiling

Correct Answer: ELISA or bridging immunoassay formats

Q16. Which of the following best describes “chimeric” monoclonal antibodies?

• Antibodies with human CDRs and murine frameworks
• Antibodies with murine variable regions fused to human constant regions
• Fully human antibodies derived from phage libraries
• Antibodies with glycoengineered Fc lacking fucose

Correct Answer: Antibodies with murine variable regions fused to human constant regions

Q17. Engineering the glycosylation pattern of an antibody Fc region can alter:

• Only its antigen specificity
• Effector functions (ADCC/CDC) and receptor interactions
• Its variable region amino acid sequence
• The pH sensitivity of the antigen-binding site

Correct Answer: Effector functions (ADCC/CDC) and receptor interactions

Q18. Which of the following defines “deimmunisation” in antibody engineering?

• Increasing immunogenic glycan content intentionally
• Removing or altering T-cell epitopes to lower immune recognition
• Adding murine sequences to enhance efficacy
• Conjugating toxins to increase cytotoxicity

Correct Answer: Removing or altering T-cell epitopes to lower immune recognition

Q19. Fc-fusion proteins (e.g., etanercept) mainly use the Fc domain to:

• Decrease circulating half-life
• Enhance solubility, dimerize the therapeutic moiety, and engage FcRn for longer half-life
• Target intracellular antigens directly
• Prevent any interaction with Fcγ receptors

Correct Answer: Enhance solubility, dimerize the therapeutic moiety, and engage FcRn for longer half-life

Q20. Which factor is least likely to influence the clinical immunogenicity of an engineered therapeutic antibody?

• Degree of sequence humanisation and presence of non-human epitopes
• Glycosylation pattern and aggregates in formulation
• Route, frequency, and dose of administration
• The batch label colour used during manufacturing

Correct Answer: The batch label colour used during manufacturing

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