Improvement of human interferon alpha secretion by Lactococcus lactis

Area of Science:

• Biotechnology
• Microbial Engineering
• Protein Expression

Background:

• Lactococcus lactis is a key host for producing recombinant proteins.
• Efficient secretion and expression of human interferon alpha 2b (IFN) are crucial for therapeutic applications.
• Optimizing protein secretion pathways in L. lactis can enhance yields and reduce production costs.

Purpose of the Study:

• To improve the secretion and expression of human interferon alpha 2b (IFN) in Lactococcus lactis.
• To evaluate the efficacy of a synthetic pro-peptide (LEISS) for enhancing IFN secretion.
• To compare the performance of two different signal peptides (SP(SlpA) and SP(Usp45)) for IFN secretion.

Main Methods:

• Fusion of a synthetic pro-peptide, LEISSTCDA (LEISS), to the N-terminus of IFN.
• Utilizing SP(SlpA) from Lactobacillus brevis as an alternative signal peptide for IFN secretion, replacing SP(Usp45).
• Assessing secretion efficiency, yield, and bioactivity of recombinant IFN through various assays.

Main Results:

• The LEISS pro-peptide fusion resulted in a significant increase in IFN secretion efficiency (12% vs. 5%) and approximately 2.8-fold higher yield.
• Employing SP(SlpA) led to a roughly 3-fold increase in IFN secretion but a decrease in total production compared to the control.
• All recombinant IFN variants demonstrated appropriate bioactivities in antiviral assays, confirming their functional integrity.

Conclusions:

• The synthetic pro-peptide LEISS is effective in enhancing both secretion efficiency and yield of human interferon alpha 2b in Lactococcus lactis.
• While SP(SlpA) boosts secretion levels, it may not be optimal for maximizing overall IFN production in this system.
• The developed methods provide a foundation for optimizing the production of bioactive human interferon alpha 2b in microbial hosts.