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    An engineered food-grade Lactococcus lactis strain for production and delivery of heat-labile enterotoxin B subunit to mucosal sites.
    BMC Biotechnol 2017 Mar 6;17(1):25. Epub 2017 Mar 6.
    Department of Epidemiology and Statistics, College of Public Health, Zhengzhou University, Zhengzhou, 450001, China.
    Background: Recent researches have been focusing on mucosal immune adjuvants, which play the key roles in mucosal immunization and have become the limitation for non-injected vaccine development. Escherichia coli heat-labile enterotoxin B subunit (LTB) was regarded as a promising mucosal adjuvant for its nontoxicity and potent activity. LTB preparation issues have always been recurring, in part owing to that the recombinant LTB expressed by E. coli does not act as its native form.

    Results: We constructed an engineered Lactococcus lactis strain using a food-grade expression system. The LTB secreted by the engineered strain was detected in the culture supernatant, constituting 10.3% of the supernatant proteins, and recognized by mouse anti-LTB antibodies. The engineered strain, co-administered orally to SPF BALB/c mice with a H. pylori vaccine candidate expressing Lpp20 antigen, could significantly enhance the Lpp20-induced mucosal SIgA antibody responses against H. pylori.

    Conclusions: This is the first report that LTB was efficiently produced and delivered via using a food-grade lactococcal expression system, which offers a novel production and utilization mode of this crucial mucosal adjuvant. The engineered L. lactis strain secreting LTB has considerable potential for oral vaccine formulation owing to its outstanding safety, adjuvant activity and high-level production.

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    J Appl Microbiol 2017 Feb 12;122(2):506-515. Epub 2016 Dec 12.
    College of Veterinary Medicine, Northeast Agricultural University, Harbin, China.
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    Methods And Results: Genetically engineered Lactobacillus casei strains expressing F4 (K88) fimbrial adhesin FaeG (rLpPG-2-FaeG) and either co-expressing heat-labile enterotoxin A (LTA) subunit with an amino acid mutation associated with reduced virulence (LTAK63) and a heat-labile enterotoxin B (LTB) subunit of E. coli (rLpPG-2-LTAK63-co-LTB) or fused-expressing LTAK63 and LTB (rLpPG-2-LTAK63-fu-LTB) were constructed. Read More
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    Can J Microbiol 2012 Nov 30;58(11):1258-67. Epub 2012 Oct 30.
    Veterinary Microbiology Department, Veterinary Medicine College, Northeast Agricultural University, Harbin, People's Republic of China.
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    Biotechnol Lett 2016 Dec 19;38(12):2169-2175. Epub 2016 Sep 19.
    Department of Epidemiology, College of Public Health, Zhengzhou University, No. 100 Kexue Dadao, Zhengzhou, 450001, China.
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