Production of interleukins MCQs With Answer

Production of interleukins MCQs With Answer

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Production of interleukins MCQs With Answer

Introduction: This quiz set covers key concepts and advanced aspects of producing interleukins for therapeutic and research purposes, tailored for M.Pharm students. It emphasizes expression systems (E. coli, yeast, mammalian cells), vector design, secretion and signal peptides, post-translational modifications including glycosylation, upstream bioprocess variables, and downstream purification strategies such as affinity tags and chromatography. Questions also explore analytical characterization, activity assays, stability, formulation, scale-up challenges, and regulatory considerations. These MCQs aim to deepen understanding of practical and theoretical issues encountered in interleukin production and quality control for biologics development.

Q1. Which expression system is most appropriate when native mammalian glycosylation of an interleukin is essential for its biological activity?

  • Escherichia coli expression system
  • Pichia pastoris expression system
  • CHO (Chinese Hamster Ovary) cell expression system
  • Cell-free bacterial lysate system

Correct Answer: CHO (Chinese Hamster Ovary) cell expression system

Q2. What is the primary disadvantage of producing interleukins in E. coli compared to mammalian systems?

  • Lower volumetric productivity
  • Lack of eukaryotic post-translational glycosylation
  • Excessive glycosylation heterogeneity
  • High risk of viral contamination

Correct Answer: Lack of eukaryotic post-translational glycosylation

Q3. Which strategy is commonly used to recover biologically active interleukin from inclusion bodies in bacterial expression?

  • Direct secretion into periplasm without refolding
  • Solubilization with chaotropes followed by stepwise refolding
  • Immediate proteolytic cleavage in inclusion bodies
  • Thermal annealing at high temperature to renature proteins

Correct Answer: Solubilization with chaotropes followed by stepwise refolding

Q4. Which affinity tag is most frequently used to facilitate purification of recombinant interleukins by immobilized metal affinity chromatography (IMAC)?

  • Fc-fusion tag
  • His6 (hexahistidine) tag
  • Maltose-binding protein (MBP) tag
  • Flag-tag

Correct Answer: His6 (hexahistidine) tag

Q5. For secreted interleukins produced in mammalian cells, which sequence component is critical to direct protein to the secretory pathway?

  • Internal ribosome entry site (IRES)
  • Kozak consensus sequence
  • Signal peptide (signal sequence)
  • Transmembrane domain

Correct Answer: Signal peptide (signal sequence)

Q6. Which downstream purification step is most effective at removing endotoxin from interleukin preparations produced in bacteria?

  • Size-exclusion chromatography alone
  • Ion-exchange chromatography under optimized conditions
  • Heat treatment at 95°C for 30 minutes
  • Dialysis against distilled water only

Correct Answer: Ion-exchange chromatography under optimized conditions

Q7. PEGylation of an interleukin is performed primarily to achieve which outcome?

  • Increase receptor binding affinity
  • Reduce in vivo half-life
  • Improve serum half-life and reduce immunogenicity
  • Introduce glycosylation sites

Correct Answer: Improve serum half-life and reduce immunogenicity

Q8. Which analytical assay directly measures the biological potency of a recombinant interleukin?

  • SDS-PAGE followed by Coomassie staining
  • Functional cell-based bioassay (e.g., proliferation or signaling readout)
  • Analytical size-exclusion chromatography (SEC)
  • Western blot with anti-His antibody

Correct Answer: Functional cell-based bioassay (e.g., proliferation or signaling readout)

Q9. In vector design for high-level expression of interleukins in mammalian cells, which promoter is commonly used for strong constitutive expression?

  • T7 promoter
  • CMV (Cytomegalovirus) immediate-early promoter
  • lac promoter
  • ADH1 promoter

Correct Answer: CMV (Cytomegalovirus) immediate-early promoter

Q10. When engineering an interleukin-Fc fusion protein, which of the following is an expected benefit?

  • Loss of receptor specificity
  • Decreased molecular size for faster renal clearance
  • Increased half-life via neonatal Fc receptor (FcRn) recycling
  • Removal of all N-linked glycosylation sites

Correct Answer: Increased half-life via neonatal Fc receptor (FcRn) recycling

Q11. Codon optimization of an interleukin gene for expression in E. coli primarily addresses which limitation?

  • Proteolysis in the periplasm
  • Differences in codon usage bias between host and source organism
  • Post-translational glycosylation patterns
  • Signal peptide cleavage inefficiency in mammalian cells

Correct Answer: Differences in codon usage bias between host and source organism

Q12. Which post-translational modification commonly affects interleukin receptor binding and circulation half-life in humans?

  • O-linked phosphorylation
  • N-linked glycosylation
  • C-terminal lipidation
  • Glycosaminoglycan attachment

Correct Answer: N-linked glycosylation

Q13. During scale-up of interleukin production in suspension CHO cultures, what parameter is most critical to control to maintain protein quality?

  • Antifoam type only
  • pH and dissolved oxygen (DO) within defined ranges
  • Culture vessel color
  • Number of passages of the seed train only

Correct Answer: pH and dissolved oxygen (DO) within defined ranges

Q14. Which chromatography method is most suitable for separating monomeric interleukin from aggregated forms based on size?

  • Reverse-phase HPLC
  • Size-exclusion chromatography (SEC)
  • Hydrophobic interaction chromatography (HIC)
  • Ion-exchange chromatography

Correct Answer: Size-exclusion chromatography (SEC)

Q15. For a recombinant interleukin to pass regulatory potency assays, which parameter is essential to demonstrate?

  • Only purity by SDS-PAGE
  • Consistent biological activity in a validated bioassay across batches
  • Presence of a His-tag irrespective of activity
  • High UV absorbance at 280 nm only

Correct Answer: Consistent biological activity in a validated bioassay across batches

Q16. Which modification of the expression construct can enhance secretion of an interleukin in mammalian cells?

  • Removing the Kozak sequence
  • Replacing the native signal peptide with a stronger signal peptide such as tissue plasminogen activator (tPA) signal
  • Deleting all glycosylation sites
  • Using a prokaryotic ribosome binding site upstream of the start codon

Correct Answer: Replacing the native signal peptide with a stronger signal peptide such as tissue plasminogen activator (tPA) signal

Q17. Which method is most appropriate to verify correct N-linked glycan structures on a recombinant interleukin?

  • UV-visible spectrophotometry
  • Mass spectrometry (MS) of released glycans
  • Native PAGE without staining
  • Flame photometry

Correct Answer: Mass spectrometry (MS) of released glycans

Q18. Which of the following is a major regulatory concern when producing interleukins in mammalian cell lines?

  • Elimination of DNA plasmid sequences from E. coli only
  • Adventitious viral contamination and control of host cell-derived impurities
  • Absence of any glycosylation on the product
  • Use of single-use pipettes during production

Correct Answer: Adventitious viral contamination and control of host cell-derived impurities

Q19. Which formulation strategy is commonly used to improve storage stability of interleukin protein therapeutics?

  • Storing at room temperature without excipients
  • Addition of stabilizing excipients such as sugars, amino acids, and polysorbates at controlled pH
  • Denaturing the protein and lyophilizing as aggregated material
  • Constant freeze-thaw cycling to maintain activity

Correct Answer: Addition of stabilizing excipients such as sugars, amino acids, and polysorbates at controlled pH

Q20. Which approach can be used to reduce heterogeneity in N-glycan structures on interleukins produced in CHO cells?

  • Switching to bacterial expression only
  • Glycoengineering of the CHO cell line to modify glycosylation pathways
  • Increasing culture temperature to 42°C
  • Omitting the signal peptide to retain protein intracellularly

Correct Answer: Glycoengineering of the CHO cell line to modify glycosylation pathways

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