A silkworm based silk gland bioreactor for high-efficiency production of recombinant human lactoferrin with antibacterial and anti-inflammatory activities

Abstract

Background Silk glands are used by silkworms to spin silk fibers for making their cocoons. These have recently been regarded as bioreactor hosts for the cost-effective production of other valuable exogenous proteins and have drawn wide attention. Results In this study, we established a transgenic silkworm strain which synthesizes the recombinant human lactoferrin (rhLF) in the silk gland and spins them into the cocoon by our previously constructed silk gland based bioreactor system. The yield of the rhLF with the highest expression level was estimated to be 12.07 mg/g cocoon shell weight produced by the transgenic silkworm strain 34. Utilizing a simple purification protocol, 9.24 mg of the rhLF with recovery of 76.55% and purity of 95.45% on average could be purified from 1 g of the cocoons. The purified rhLF was detected with a secondary structure similar with the commercially purchased human lactoferrin. Eight types of N-glycans which dominated by the GlcNAc (4) Man (3) (61.15%) and the GlcNAc (3) Man (3) (17.98%) were identified at the three typical N-glycosylation sites of the rhLF. Biological activities assays showed the significant evidence that the purified rhLF could relief the lipopolysaccharide (LPS)-induced cell inflammation in RAW264.7 cells and exhibit potent antibacterial bioactivities against the Escherichia coli ( E. coli ) and Bacillus subtilis. Conclusions These results show that the middle silk gland of silkworm can be an efficient bioreactor for the mass production of rhLF and the potential application in anti-inflammation and antibacterial. Electronic supplementary material The online version of this article (10.1186/s13036-019-0186-z) contains supplementary material, which is available to authorized users.

Effect of Thermal Processing on Physico-Chemical and Antioxidant Properties in Mulberry Silkworm (Bombyx mori L.) Powder

“…Studies revealed that some pigments found on the yellow Nangnoi silk (Thai silk) are associated with the presence of carotenoids and flavonoids [7,8]. The phenolic compounds are well-known for antioxidant activity as well as some biological functions such as anti-hypertensive [9], antiviral [10], antioxidant [11], antibacterial, and anti-inflammatory activities [12]. Dutta et al [13] reported that the antioxidant potential of the edible insect Vespa affinis L. could mediate its therapeutic activities in oxidative stress-associated health disorders.…”

Fabrication of a Silk Sericin Hydrogel System Delivering Human Lactoferrin Using Genetically Engineered Silk with Improved Bioavailability to Alleviate Chemotherapy-Induced Immunosuppression

“…We previously constructed a transgenic silkworm strain that could specifically produce silk cocoons with rhLF distributed in its sericin layer (Figure 1A). 34 Via rearing this transgenic silkworm strain and letting the silkworm do the hard work, we could harvest (timeand cost-effectively) silk fiber with functional rhLF at a large scale; thus, the shortage of the rhLF resource could be solved well. Sericins from WT and rhLF silks were extracted using 8 M urea buffer to fabricate sericin hydrogels.…”

“…Fabrication of Silk Sericin Hydrogel Loaded with rhLF. Wild-type (WT) and rhLF silk cocoons were obtained by rearing a WT or rhLF silkworm strain 34 and wild type silkworm strain (D9L) using fresh mulberry leaves or artificial diet, and the two types of cocoons were stored at room temperature before use. Extraction of sericin was performed as previously reported with some modification.…”

“…Silk fibers integrated with rhLF in the sericin layer were produced by our previously generated transgenic rhLF silkworm strain. 34 Sericin, together with rhLF, was spontaneously extracted to fabricate rhLF-loaded sericin hydrogels, which exhibit the typical features of sericin-derived biomaterials, including porous microstructure, good biocompatibility, biodegradation, and sustained release of rhLF, and effectively enhanced the immunity of immunosuppressed mice even at low dosage compared to the high dosage treatment with rhLF solution to achieve similar therapeutic effects. These results suggest that our genetically engineered rhLF-sericin hydrogel will be a potential oral biomaterial for cancer chemotherapy and patient immune enhancement.…”

Lactoferrin Can Attenuate SARS-CoV-2: An Analysis of Evidential Relations

“…Inflammatory diseases such as neurodegenerative illness, inflammatory bowel disorder, dermatitis, pulmonary diseases, and arthritis have been shown to stimulate Lf. Furthermore, Lf treatment has been demonstrated in most animal experiments to reduce experimental inflammation in such organs 102 . For instance, Lf prevents chemical and IL-1β -driven cutaneous inflammation in humans and animals, chemically induced inflammatory bowel disease in rats and mice, nonsteroidal anti-inflammatory drugs (NSAIDs)-induced colon damage in rodents, and inflammation in a rat model of rheumatoid arthritis 103 .…”