Optimization of medium composition to increase the expression of recombinant human interferon-β using the Plackett-Burman and central composite design in E. coli SE1

Recent advances in culture medium design for enhanced production of monoclonal antibodies in CHO cells: A comparative study of machine learning and systems biology approaches

The production of monoclonal antibodies (mAbs) using Chinese Hamster Ovary (CHO) cells has revolutionized the treatment of numerous diseases, solidifying their position as a cornerstone of the biopharmaceutical industry. However, achieving maximum mAb production while upholding strict product quality standards remains a significant hurdle. Optimizing cell culture media emerges as a critical factor in this endeavor, requiring a nuanced understanding of the complex interplay of nutrients, growth factors, and other components that profoundly influence cellular growth, productivity, and product quality. Significant strides have been made in media optimization, including techniques such as media blending, one factor at a time, and statistical design of experiments approaches. The present review provides a comprehensive analysis of the recent advancements in culture media design strategies, focusing on the comparative application of systems biology (SB) and machine learning (ML) approaches. The applications of SB and ML in optimizing CHO cell culture medium and successful examples of their use are summarized. Finally, we highlight the immense potential of integrating SB and ML, emphasizing the development of hybrid models that leverage the strengths of both approaches for robust, efficient, and scalable optimization of mAb production in CHO cells. This review provides a roadmap for researchers and industry professionals to navigate the complex landscape of mAb production optimization, paving the way for developing next-generation CHO cell culture media that drive significant improvements in yield and productivity.

Optimized production of a truncated form of the recombinant neuraminidase of influenza virus in Escherichia coli as host with suitable functional activity

BACKGROUND

To discover effective drugs for treating Influenza (a disease with high annual mortality), large amounts of recombinant neuraminidase (NA) with suitable catalytic activity are needed. However, the functional activity of the full-length form of this enzyme in the bacterial host (as producing cells with a low cost) in a soluble form is limited. Thus, in the present study, a truncated form of the neuraminidase (derived from California H1N1 influenza strain) was designed, then biosynthesized in Escherichia coli BL21 (DE3), Shuffle T7, and SILEX systems. E. coli BL21 (DE3) was selected as a best host for statistical optimization. Using central composite design methodology, neuraminidase expression level was measured at 20 different runs considering most effective factors including; concentration of isopropyl-β-D-thiogalactopyranoside (IPTG), temperature, and induction time.

RESULT

The recombinant neuraminidase was purified using Ni-affinity chromatography in soluble form. The neuraminidase expression was confirmed by western blot technique with a molecular mass of 48 kDa. The optimum expression condition was at temperature (30°C), induction time (3 h), and concentration of IPTG (0.6 mM) resulting in maximum neuraminidase expression (7.6 µg/mL) with P < 0.05. The analysis of variance with the significant value of R2 (0.97) indicated that the quadratic model utilized for this prediction was highly significant (p < 0.0001). Applying the optimized condition led to a ~ 2.2-fold increase in NA expression level (from 3.4 to 7.6 µg/ml). The kinetic parameters were also confirmed by fluorescent signals (by 2'-(4-Methylumbelliferyl)-α-D-N acetyl neuraminic acid substrate) with specific activity; ~3.5 IU/mg and Km: 86.49 ± 0.1 µ, close to the Vibrio Cholera neuraminidase with specific activity; 4 IU/mg. The neuraminidase inhibition test confirmed the inhibition of the neuraminidase activity by the drug inhibitor (Oseltamivir) compared to the control sample.

CONCLUSION

The high quality and proper functional activity of the truncated neuraminidase described in this research show that E. coli can be a suitable host for a wide range of applications with less cost and risk compared to eukaryotic expression systems.

Production of recombinant human insulin from a promising Pseudomonas fluorescens cell factory and its kinetic modeling

Insulin intake is recommended for diabetics in addition to a proper diet and lifestyle to maintain adequate blood glucose level. Currently, there is a need for an alternative expression system for insulin production as the current expression systems may not meet the growing demand due to various constraints. Here, we demonstrate the synthesis of human insulin in an unconventional expression system based on Pseudomonas fluorescens, a BSL 1 bacterium. Human insulin was produced in the form of proinsulin fused with fusion protein. Then, the proinsulin fusion protein was purified using Ni-NTA chromatography and converted into human insulin. The physicochemical parameters for producing proinsulin fusion protein are optimized. Glucose and ammonium chloride are determined to be suitable carbon and nitrogen sources, respectively. The validity of insulin and proinsulin fusion protein is assessed using western blot and quantified using ELISA techniques. Up to 145.35 mg/l of the proinsulin fusion protein is achieved at the shake flask level. Further, MALDI-TOF and RP-HPLC analysis of the purified human insulin were observed to be close to the theoretical value and insulin standard, respectively. The expression of the recombinant fusion protein was found to be 214.7 mg/l in a batch bioreactor, a ∼48% enhancement over the shake flask level. Further, kinetic modeling was performed to understand the system regarding growth, substrate utilization and product formation, and to estimate the various kinetic parameters. This study establishes the potential of the P. fluorescens expression system for producing human insulin.

Engineered polyspecific antibodies: A new frontier in the field of immunotherapeutics

The 21st-century beginning remarked with the huge success of monospecific MAbs, however, in the last couple of years, polyspecific MAbs (PsAbs) have been an interesting topic and show promise of being biobetter than monospecific MAbs. Polyspecificity, in which a single antibody serves multiple specific target binding, has been hypothesized to contribute to the development of a highly effective antibody repertoire for immune defence. This polyspecific MAb trend represents an explosion that is gripping the whole pharmaceutical industry. This review is concerned with the current development and quality enforcement of PsAbs. All provided literature on monospecific MAbs and polyspecific MAbs (PsAbs) were searched using various electronic databases such as PubMed, Google Scholar, Web of Science, Elsevier, Springer, ACS, Google Patent and books via the keywords Antibody engineering, Polyspecific antibody, Conventional antibody, non-conventional antibody, and Single domain antibody. In the literature, there are more than 100 different formats to construct PsAb by quadroma technology, chemical conjugation and genetic engineering. Till March 2023, nine PsAb have been approved around the world, and around 330 are in advanced developmental stages, showing the dominancy of PsAb in the growing health sector. Recent advancements in protein engineering techniques and the fusion of non-conventional antibodies have made it possible to create complex PsAbs that demonstrate higher stability and enhanced potency. This marks the most significant achievement for cancer immunotherapy, in which PsAbs have immense promise. It is worth mentioning that seven out of the nine PsAbs have been approved as anti-cancer therapy. As PsAbs continue to acquire prominence, they could pave the way for the development of novel immunotherapies for multiple diseases.

Enhanced fatty acid storage combined with the multi-factor optimization of fermentation for high-level production of docosahexaenoic acid in Schizochytrium sp

Schizochytrium sp. hasreceived much attention for itsability to synthesize and accumulate high-level docosahexaenoic acid (DHA), which can reach nearly 40 % of total fatty acids. In this study, the titer of DHA in Schizochytrium sp. was successfully improved by enhancing DHA storage through overexpressing the diacylglycerol acyltransferase (ScDGAT2C) gene, as well as optimizing the supply of precursors and cofactors required for DHA synthesis by response surface methodology. Notably, malic acid, citric acid, and biotin showed synergistic and time-dependent effects on DHA accumulation. The maximum lipid and DHA titers of the engineered Schizochytrium sp. strain reached 84.28 ± 1.02 g/L and 42.23 ± 0.69 g/L, respectively, with the optimal concentration combination (1.62 g/L malic acid + 0.37 g/L citric acid + 8.28 mg/L biotin) were added 48 h after inoculation. This study provides an effective strategy for improving lipid and DHA production in Schizochytrium sp.

Fused human paraoxonase 1 as a prophylactic agent against organophosphate poisoning

Organophosphates (OPs) are highly neurotoxic compounds and certain OP-compounds are also exploited as a weapon of mass destruction and chemical warfare in terrorist attacks. Available prophylactic and post-exposure treatments are less effective and also have serious side-effects. Thus, there is a dire need to develop effective and safe prophylactic agent(s) against OP-poisoning. Human Paraoxonase 1 (hPON1) can hydrolyze a wide range of OP molecules and can be developed as an effective and safe prophylactic agent. Thus, there is a dire need in the art to develop variant(s) of rhPON1 that not only possess 'good' OP-hydrolyzing activity but also have improved pharmacokinetic properties. In this report, we describe the characterization of the fused hPON1 (FHP) variant that not only exhibit enhanced in vivo pharmacokinetic properties but also delay / prevent the symptoms of OP-poisoning and prevents OP-induced mortality in rats.

Enhancing docosahexaenoic acid production of Schizochytrium sp. by optimizing fermentation using central composite design

Docosahexaenoic acid (DHA) can improve human and animal health, particularly including anti-inflammatory, antioxidant, anticancer, neurological, and visual functions. Schizochytrium sp. is a marine heterotrophic protist producing oil with high DHA content, which is widely used in animal and food production. However, different fermentation conditions have intensive impacts on the growth and DHA content of Schizochytrium sp. Thus, this study aimed to enhance the DHA yield and concentration of Schizochytrium sp. I-F-9 by optimizing the fermentation medium. First, a single-factor design was conducted to select a target carbon and nitrogen source from several generic sources (glucose, sucrose, glycerol, maltose, corn syrup, yeast extract, urea, peptone, and ammonium sulfate). The Plackett-Burman design and the central composite design (CCD) were utilized to optimize the fermentation mediums. Schizochytrium sp. in 50-mL fermentation broth was cultured in a 250 mL shake flask at 28 °C and 200 rpm for 120 h before collecting the cell pellet. Subsequently, the cell walls were destroyed with hydrochloric acid to extract the fatty acid using n-hexane. The DHA content was detected by gas chromatography. The single-factor test indicated that glucose and peptone, respectively, significantly improved the DHA content of Schizochytrium sp. compared to the other carbon and nitrogen sources. Glucose, sodium glutamate, and sea crystal were the key factors affecting DHA production in the Plackett-Burman test (P = 0.0247). The CCD result showed that DHA production was elevated by 34.73% compared with the initial yield (from 6.18 ± 0.063 to 8.33 ± 0.052 g/L). Therefore, the results of this study demonstrated an efficient strategy to increase the yield and content of DHA of Schizochytrium sp.

Isolation and identification of a new biocontrol bacteria against Salvia miltiorrhiza root rot and optimization of culture conditions for antifungal substance production using response surface methodology

Background

S. miltiorrhiza root rot is a soil-borne disease mainly caused by Fusarium solani and Fusarium oxysporum, which has spread rapidly in China in recent years. To reduce the amount of pesticides to control this plant fungal disease, biological control using endophytic bacteria is a promising method. Many endophytic bacteria show good biocontrol potential against various plant fungal diseases. The aims of this study were to isolate and identify endophytic bacteria with antifungal activity from Salvia miltiorrhiza plant tissue. In order to increase antifungal substances production, the culture conditions of the isolated DS-R5 strain were optimized through response surface methodology.

Results

Thirteen endophytic bacteria with antifungal activity against the target pathogenic fungus were successfully screened. The DS-R5 strain that had the strongest antifungal activity was identified based on morphological, physiological and biochemical characteristics, 16S rRNA and gyrB sequence analysis.The results of response surface methodology experiments showed that the optimal values of the three significant factors were as follows: medium volume, 51.0 ml; initial pH, 6.7; fermentation temperature, 33.1 °C. Under these optimal culture conditions, the titer of antifungal substances produced by the DS-R5 strain was 77.6% higher than that under the initial culture conditions.

Conclusions

The antifungal activity of endophytic bacteria from Salvia miltiorrhiza has been demonstrated for the first time, which may benefit future crop quality and production. In addition, response surface methodology can be well applied the optimization of culture conditions for antifungal substance, which lays the foundation for further research on strain DS-R5.