Acta Veterinaria et Zootechnica Sinica ›› 2025, Vol. 56 ›› Issue (9): 4529-4545.doi: 10.11843/j.issn.0366-6964.2025.09.032

• Preventive Veterinary Medicine • Previous Articles     Next Articles

Analysis of the Preventive Effect of Recombinant E. coli Expressing rFel d 1 against Fel d 1-Induced Allergic Asthma

MAI Yanqi1(), SUN Xiaozheng1, LIU Xiaoxuan1, LIANG Xinglan1, HUANG Ying1, WU Xiaojuan1, LIU Xiande1,*(), PEI Yechun1,2,*()   

  1. 1. School of Life and Health Sciences, Hainan University, Haikou 570228, China
    2. Hainan Province Key Laboratory of One Health, Haikou 570228, China
  • Received:2024-12-13 Online:2025-09-23 Published:2025-09-30
  • Contact: LIU Xiande, PEI Yechun E-mail:1204737571@qq.com;xiande_liu79@hainanu.edu.cn;ycpei@hainanu.edu.cn

Abstract:

Felis domesticus allergen 1 (Fel d 1), the major allergen responsible for cat-induced allergic diseases, can trigger symptoms ranging from mild allergic rhinitis to life-threatening asthmatic reactions. This study developed a novel immune intervention strategy based on an antigen delivery system: utilizing recombinant Escherichia coli Nissle 1917 (EcN) to achieve in vivo expression of rFel d 1, aiming to prevent allergic reactions induced by rFel d 1. The gene sequence of the major Fel d 1 was obtained from the NCBI GenBank database. The coding sequences (CDS) of Chain 1 and Chain 2 were selected, with a covalent linkage formed between the C-terminal cysteine residue (Cys) of Chain 1 and the N-terminal valine residue (Val) of Chain 2 to generate recombinant Fel d 1 (rFel d 1). A triple GS repeat sequence was introduced at the N-terminus of rFel d 1, while a 6×His tag was added to the C-terminus. After codon optimization, the construct was cloned into the pBad vector to generate the prokaryotic expression vector pBad-rFel d 1. The pBad-rFel d 1 plasmid was then transformed into EcN competent cells to construct the recombinant E. coli strain EcNrFel d 1. In a murine allergy model, the preventive efficacy of EcNrFel d 1 against rFel d 1-induced allergic reactions was comprehensively evaluated. We found that pre-administration with the recombinant E. coli strain EcNrFel d 1 capable of expressing rFel d 1 in vivo could effectively prevent airway hyperresponsiveness and the elevation of IgE levels, protecte lung tissues from pathological changes and avoid local or systemic allergic reactions specifically activated by rFel d 1, and prevent the imbalance of Th1/Th2 and Th17/Treg in the body. Based on the inherent colonization advantages and sustained-release properties of probiotic EcN, this study developed a preventive recombinant E. coli strain EcNrFel d 1, Which effectively prevents rFel d 1-induced allergic reactions by modulating Th1/Th2 and Treg/Th17 immune balance while inducing the production of blocking antibodies.

Key words: allergic asthma, allergens, probiotics, airway inflammation, protein vaccines

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