Stable transformation of Spirulina (Arthrospira) platensis: a promising microalga for production of edible vaccines

Abstract

The planktonic blue-green microalga Spirulina (Arthrospira) platensis possesses important features (e.g., high protein and vital lipids contents as well as essential vitamins) and can be consumed by humans and animals. Accordingly, this microalga gained growing attention as a new platform for producing edible-based pharmaceutical proteins. However, there are limited successful strategies for the transformation of S. platensis, in part because of an efficient expression of strong endonucleases in its cytoplasm. In the current work, as a pilot step for the expression of therapeutic proteins, an Agrobacterium-based system was established to transfer gfp:gus and hygromycin resistance (hyg) genes into the genome of S. platensis. The presence of acetosyringone in the transfection medium significantly reduced the transformation efficiency. The PCR and real-time RT-PCR data confirmed the successful integration and transcription of the genes. Flow cytometry and β-glucuronidase (GUS) activity experiments confirmed the successful production of GFP and the enzyme. Moreover, the western blot analysis showed a ~ 90 kDa band in the transformed cells, indicating the successful production of the GFP:GUS protein. Three months after the transformation, the gene expression stability was validated by histochemical, flow cytometry, and hygromycin B resistance analyses.

Prophylactic domain-based vaccine against SARS-CoV-2, causative agent of COVID-19 pandemic

“…To produce the designed recombinant protein vaccine in a lab setting, a suitable expression host such as microalgae can be used to express the recombinant vaccine with the optimal post-translational modi cations 56,57 . In the case of SAMV construct, although both the non-viral delivery systems (e.g., lipid nanoparticles 58 , polymeric nanoparticles 59 , and cell-penetrating peptides 60 ), and in vivo transfection systems (e.g., injection, electroporation, and gene gun) can improve the stability and cellular uptake e cacy, however, the naked SAM vaccine can be taken up as well by signi cantly antigen-presenting cells without any additional required formulation 61 .…”

Lactobacillus plantarum induces apoptosis in gastric cancer cells via modulation of signaling pathways in Helicobacter pylori

“…39 It should be noted that probiotics similar to many of microalgae (e.g., Dunaliella and Spirulina species) may be generally regarded as safe for use in animal and human systems. 29,40,41 Taken all, these organisms could be assigned as an important vehicle for oral delivery of different biologics such as edible vaccines. 42…”

Designing a new generation of expression toolkits for engineering of green microalgae; robust production of human interleukin-2

“…20 The gene silencing is deemed to happen at both transcriptional and translational levels due to the functional presence of nuclease and proteases in the microalgae cytosol. 4 In addition, the insertion of the genes of interest (GOIs) into the nuclear genome might occur randomly, causing the truncate of the important host genes or even cell death. 10 Recent researches identified codon optimization using native and chimeric strong promoters and showed that the untranslated regions (UTRs) might be involved in the gene expression of microalgae.…”

“…As a result, they can be exploited for different biomedical applications even the treatment of various diseases such as cancer. 4 Moreover, the eyespot and channelrhodopsins in the microalgae are located in the center of optogenetic and neuroscience for illuminating the fundamentals of eyes and brain functions. [5][6][7] Although the genetic manipulation of microalgae is lower than that of the other expression hosts, their key characteristics make them an interesting expression platform for the production of recombinant proteins.…”

“…and Chlorella plasmids is another approach for the stable transformation of microalgae and also a wide range of hosts such as plants, yeasts, fungi, and even human cells. 4,10,29,30 Herein, we constructed a novel Agrobacterium-2Abased (the so-called GMAE plasmid) system, containing hsp70/Int-1/rbcs2 chimeric promoter, microalgae specific Kozak sequence, a chimeric 2A peptide, Int-1 and -3 of the rbcS2 gene and UTRs optimized for the robust and stable expression of hIL-2 gene in the nuclear of the C. reinhardtii. The GMAE plasmid is also successfully utilized for the efficient transformation of C. vulgaris and D. salina cells with the hIL-2 gene.…”