Human interleukin-1 receptor antagonist: large-scale expression in Bacillus brevis 47-5Q

Available strategies for improved expression of recombinant proteins in Brevibacillus expression system: a review

Brevibacillus offers great potential as a recombinant protein expression host because of its exceptional abilities to synthesize and excrete proteins and its low extracellular protease activity. Despite these strengths, effective recombinant expression strategies are still the key to achieving high-level expression of recombinant proteins in Brevibacillus due to individual differences among strains and target proteins. Many strategies have been developed to improve recombinant protein expression in Brevibacillus. This review begins by introducing the processes used to establish and apply the Brevibacillus expression system, and then critically discusses the strategies available for improving recombinant protein expression in Brevibacillus, including optimization of the host and the expression vector, co-expression of a fusion partner or foldase, and optimization of the fermentation process. Finally, the prospects for further improvement of recombinant protein expression based on Brevibacillus are also discussed. This review is intended to provide a strategic reference for scientists wanting to improve the expression of a specific recombinant protein in Brevibacillus or other expression systems.

Evaluating the autoinduction expression system and one-step purification for high-level expression and purification of gallbladder-derived rhIL-1Ra

Recent advancement in fermentation technologies resulted in the increased yields of recombinant proteins of biopharmaceutical and medicinal importance. Consequently, there is an important task to develop simple and easily scalable methods that can facilitate the production of high-quality recombinant protein. Most of the recent reports described the expression of recombinant human IL-1 receptor antagonist (rhIL-1Ra) in Escherichia coli using isopropyl-β-d-thiogalacto pyranoside (IPTG), a nonmetabolizable and expensive compound, as an expression inducer. In this study, we describe the expression and one-step purification of gallbladder-derived rhIL-1Ra by autoinduction in E. coli. This method includes special media that automatically induce the target protein expression from T7 promoter and allow the production of the target protein in high yield than the conventional IPTG induction method. In addition to fermentation process improvements, one-step purification strategy is essential to make the process economical. We developed a single-step cation exchange chromatography and obtained 300 mg/L of rhIL-1Ra with 98% purity. Purified protein was characterized by SDS-PAGE and Ion exchange HPLC (IEX-HPLC). The described method can be used to scale up the production of rhIL-1Ra and other recombinant proteins.

Synthesis of N-terminally linked protein and peptide dimers by native chemical ligation

Dimerization can be utilized to double the molecular weight of proteins and peptides and potentially increase their avidity of binding to target receptors. These dimerization effects may be utilized to increase in vivo half-lives in a manner similar to PEGylation and may also improve biological activity. In this paper, we report a new strategy for the synthesis of N-terminally linked protein and peptide homodimers utilizing native chemical ligation to conjugate a short dithioester linker to the N-terminal cysteines of protein and peptide monomers to form dimers in a single step. This strategy is general and has been applied to the production of dimers from three recombinantly expressed polypeptides, the IgG binding domain Protein G, an HIV entry inhibitor peptide C37H6, and human interleukin-1 receptor antagonist (IL-1ra). The biological activities of the C37H6 and IL-1ra dimers produced by these methods were retained or even slightly increased when compared to their corresponding monomers.

On-Column Refolding and Purification of Recombinant Human Interleukin-1 Receptor Antagonist (rHuIL-1ra) Expressed as Inclusion Body in Escherichia coli

Recombinant human interleukin-1 receptor antagonist (rHuIL-1ra) was produced in E. coli as an inclusion body. rHuIL-1ra was purified to Over 98% purity by anion exchange chromatography after on-column refolding. The optimized processes produced more than 2 g pure refolded rHuIL-1ra per 1 l culture, corresponding to a 44% recovery, without an intermediate dialysis step. Refolded rHuIL-1ra had full biological activity with the MTT assay. An intramolecular disulfide linkage in the oxidized recombinant protein was suggested by data from HPLC and non-reducing SDS-PAGE.

In vivo mucosal delivery of bioactive human interleukin 1 receptor antagonist produced by Streptococcus gordonii

BACKGROUND

Interleukin-1 (IL-1) is a cytokine involved in the initiation and amplification of the defence response in infectious and inflammatory diseases. IL-1 receptor antagonist (IL-1ra) is an inactive member of the IL-1 family and represents one of the most potent mechanisms for controlling IL-1-dependent inflammation. IL-1ra has proven effective in the therapy of acute and chronic inflammatory diseases in experimental animal models and also in preliminary clinical trials. However, optimisation of therapeutic schedules is still needed. For instance, the use of drug delivery systems targeting specific mucosal sites may be useful to improve topical bioavailability and avoid side effects associated with systemic administration.

RESULTS

In order to develop systems for the delivery of IL-1ra to mucosal target sites, a Streptococcus gordonii strain secreting human IL-1ra was constructed. The recombinant IL-1ra produced by S. gordonii was composed of the four amino acid residues RVFP of the fusion partner at the N-terminus, followed by the mature human IL-1ra protein. RFVP/IL-1ra displayed full biological activity in vitro in assays of inhibition of IL-1beta-induced lymphocyte proliferation and was released by recombinant S. gordonii in vivo both at the vaginal and the gastrointestinal mucosa of mice. RFVP/IL-1ra appeared beneficial in the model of ulcerative colitis represented by IL-2-/- mice (knock-out for the interleukin-2 gene), as shown by the body weight increase of IL-2-/- mice locally treated with S. gordonii producing RFVP/IL-1ra.

CONCLUSIONS

These results indicate that recombinant S. gordonii can be successfully used as a delivery system for the selective targeting of mucosal surfaces with therapeutic proteins.

High-level production of recombinant chicken interferon-gamma by Brevibacillus choshinensis

Cytokines, such as interferon-gamma have been shown to have adjuvant and growth promoting activity in poultry and livestock and have the potential to be used as alternatives to antibiotics. We have developed an efficient system for commercial-scale synthesis of recombinant chicken interferon-gamma (ChIFN-gamma) using Brevibacillus choshinensis as the host for protein production. The ChIFN-gamma expression vector, pNCIFN, was constructed using the novel Escherichia coli-B. choshinensis shuttle vector, pNCMO2. ChIFN-gamma expression was optimized by investigating different culture conditions and different host B. choshinensis mutants. The highest level of production was observed using the B. choshinensis HPD31-MB2 strain grown at 30 degrees C, where ChIFN-gamma was produced at approximately 300-500 mg/L. ChIFN-gamma was also produced as a His-tagged fusion protein by using the pNCHis-IFN expression vector, a derivative of pNCMO2. The protein was constitutively secreted into the culture supernatant and could be partially purified in a single step using a Ni-nitrilotriacetic acid column. This recombinant His-ChIFN-gamma was shown to have the same biological activity as native ChIFN-gamma.