Production of Interferon by rDNA technology is essential for B. Pharm students focusing on pharmaceutical biotechnology and biologics manufacturing. The topic includes recombinant DNA cloning, vector design, host selection (E. coli, yeast, mammalian cells), optimization of expression, folding and post-translational modifications, purification strategies, and formulation approaches such as pegylation. Students learn interferon types (IFN‑α, IFN‑β, IFN‑γ), bioassays, scale-up challenges, quality control, regulatory requirements, and clinical applications. Emphasis on troubleshooting issues like inclusion bodies, glycosylation differences, and endotoxin removal links theory to practice in drug development. This foundation equips graduates for roles in research, manufacturing, and regulatory affairs. Now let’s test your knowledge with 30 MCQs on this topic.
Q1. Which interferon type is most commonly produced recombinantly for antiviral and antitumor therapies?
- IFN‑α
- IFN‑β
- IFN‑γ
- IFN‑lambda
Correct Answer: IFN‑α
Q2. Which host expression system is preferred for high-yield, cost-effective production of non-glycosylated interferon?
- Pichia pastoris
- CHO cells
- Escherichia coli
- Human embryonic kidney (HEK) cells
Correct Answer: Escherichia coli
Q3. What is the primary challenge when expressing interferon in E. coli?
- Excessive glycosylation
- Formation of inclusion bodies
- Low plasmid stability
- High secretion into medium
Correct Answer: Formation of inclusion bodies
Q4. Which purification method is most commonly used for recombinant interferon with a polyhistidine tag?
- Size-exclusion chromatography
- Ion-exchange chromatography
- Immobilized metal affinity chromatography (IMAC)
- Hydrophobic interaction chromatography
Correct Answer: Immobilized metal affinity chromatography (IMAC)
Q5. Why is pegylation applied to recombinant interferon formulations?
- To increase immunogenicity
- To reduce biological half-life
- To enhance solubility and prolong circulation half-life
- To promote rapid renal clearance
Correct Answer: To enhance solubility and prolong circulation half-life
Q6. Which promoter is commonly used in E. coli expression vectors for high-level recombinant protein expression?
- CMV promoter
- T7 promoter
- AOX1 promoter
- SV40 promoter
Correct Answer: T7 promoter
Q7. For interferon requiring glycosylation, which host is most appropriate?
- Escherichia coli
- Pichia pastoris
- CHO (Chinese Hamster Ovary) cells
- Mycobacterium smegmatis
Correct Answer: CHO (Chinese Hamster Ovary) cells
Q8. What is an advantage of using yeast (Pichia pastoris) over E. coli for interferon production?
- Higher endotoxin content
- Capability for simple eukaryotic glycosylation and secretion
- Lower protein folding capacity
- Inability to scale up fermentation
Correct Answer: Capability for simple eukaryotic glycosylation and secretion
Q9. Which analytical assay specifically measures antiviral activity of interferon?
- ELISA for interferon concentration
- Plaque reduction or viral inhibition bioassay
- SDS-PAGE densitometry
- Mass spectrometry peptide mapping
Correct Answer: Plaque reduction or viral inhibition bioassay
Q10. During refolding of interferon from inclusion bodies, which reagent is commonly used to prevent incorrect disulfide bond formation?
- EDTA
- DTT (dithiothreitol)
- Imidazole
- Lysozyme
Correct Answer: DTT (dithiothreitol)
Q11. Which chromatographic step is most useful for removing host cell proteins and nucleic acids after initial capture of interferon?
- Affinity chromatography
- Ion-exchange chromatography
- Gel filtration as first step
- Reverse-phase HPLC as primary step
Correct Answer: Ion-exchange chromatography
Q12. What is a critical regulatory concern for recombinant interferon produced in bacterial hosts?
- Residual mammalian viruses
- Endotoxin contamination
- Glycosylation heterogeneity
- Excessive phosphorylation
Correct Answer: Endotoxin contamination
Q13. Which post-translational modification significantly affects interferon pharmacokinetics and receptor interactions?
- Phosphorylation
- Glycosylation
- Sumoylation
- Methylation
Correct Answer: Glycosylation
Q14. What is the purpose of codon optimization when designing interferon genes for expression?
- To increase plasmid size
- To match host tRNA abundance and improve translation efficiency
- To add signal peptides automatically
- To introduce more restriction sites
Correct Answer: To match host tRNA abundance and improve translation efficiency
Q15. Which formulation consideration reduces aggregation of recombinant interferon in storage?
- High temperature storage
- Use of stabilizing excipients like sugars and surfactants
- Frequent freeze–thaw cycles
- Inclusion of proteases
Correct Answer: Use of stabilizing excipients like sugars and surfactants
Q16. Which immune-related adverse effect is commonly associated with therapeutic interferon use?
- Hypoglycemia
- Flu-like symptoms and myelosuppression
- Hyperkalemia
- Renal nephrolithiasis
Correct Answer: Flu-like symptoms and myelosuppression
Q17. In scale-up, which bioreactor parameter most directly affects recombinant protein yield?
- pH control
- Oxygen transfer rate (kLa)
- Incubator color
- Type of sterile filter only
Correct Answer: Oxygen transfer rate (kLa)
Q18. Which vector element ensures high-copy replication in E. coli expression plasmids?
- Signal peptide
- Origin of replication (e.g., ColE1)
- Polyadenylation signal
- Internal ribosome entry site (IRES)
Correct Answer: Origin of replication (e.g., ColE1)
Q19. For removal of endotoxin from recombinant interferon preparations, which method is commonly used?
- Protein A chromatography
- Polymyxin B affinity or phase separation methods
- Ultrafiltration only
- Heat denaturation at 95 °C
Correct Answer: Polymyxin B affinity or phase separation methods
Q20. What is the role of a signal sequence when expressing interferon in a secretory system?
- To prevent secretion
- To direct the nascent protein into the secretory pathway for extracellular release
- To increase plasmid copy number
- To cleave the protein into smaller fragments
Correct Answer: To direct the nascent protein into the secretory pathway for extracellular release
Q21. Which analytical technique confirms the primary sequence and identity of recombinant interferon?
- Western blot without mass spec
- Mass spectrometry peptide mapping
- UV absorbance at 260 nm
- ELISA for activity only
Correct Answer: Mass spectrometry peptide mapping
Q22. During expression optimization, which parameter is commonly reduced to decrease inclusion body formation in E. coli?
- Induction temperature
- Culture pH to extreme levels
- Media buffering
- Antibiotic concentration
Correct Answer: Induction temperature
Q23. What is the main reason for using fusion tags (e.g., GST, His) in interferon production?
- To decrease solubility
- To facilitate purification and sometimes improve solubility
- To shorten protein half-life
- To increase endotoxin levels
Correct Answer: To facilitate purification and sometimes improve solubility
Q24. Which parameter is evaluated during interferon potency assays?
- Protein tertiary structure only
- Biological activity measured by cell-based assays
- Only endotoxin level
- pH of formulation
Correct Answer: Biological activity measured by cell-based assays
Q25. What is the effect of glycosylation differences when switching from mammalian to bacterial production for interferon?
- No effect on pharmacokinetics
- Potential loss of activity, altered stability and immunogenicity
- Guaranteed increase in potency
- Automatic improvement of receptor binding
Correct Answer: Potential loss of activity, altered stability and immunogenicity
Q26. Which regulatory document outlines quality requirements for recombinant biologics like interferon?
- ICH guidelines and WHO biologics guidelines
- USP monographs only
- Farmacopeia unrelated to biologics
- ISO 9001 only
Correct Answer: ICH guidelines and WHO biologics guidelines
Q27. Which sterilization concern is unique for protein biologics compared to small-molecule drugs?
- High-temperature autoclaving is always acceptable
- Sterilization must preserve tertiary structure and activity, so filtration is preferred
- No sterilization required
- Gamma irradiation enhances protein function
Correct Answer: Sterilization must preserve tertiary structure and activity, so filtration is preferred
Q28. Which is a common method to assess glycosylation patterns of recombinant interferon?
- RNA sequencing
- Glycan analysis by mass spectrometry or HPLC
- Simple Bradford assay
- pH titration
Correct Answer: Glycan analysis by mass spectrometry or HPLC
Q29. What is one advantage of using mammalian expression systems for interferon production?
- Lower cost than bacterial systems
- Proper human-like post-translational modifications and folding
- Faster growth and simpler media requirements
- Elimination of all regulatory hurdles
Correct Answer: Proper human-like post-translational modifications and folding
Q30. Which downstream step is crucial to ensure removal of DNA contaminants from recombinant interferon preparations?
- DNAse treatment and chromatographic steps designed for impurity removal
- Only buffer exchange
- Heat shock at 60 °C for 5 minutes
- Adding EDTA alone
Correct Answer: DNAse treatment and chromatographic steps designed for impurity removal
I am a Registered Pharmacist under the Pharmacy Act, 1948, and the founder of PharmacyFreak.com. I hold a Bachelor of Pharmacy degree from Rungta College of Pharmaceutical Science and Research. With a strong academic foundation and practical knowledge, I am committed to providing accurate, easy-to-understand content to support pharmacy students and professionals. My aim is to make complex pharmaceutical concepts accessible and useful for real-world application.
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