Engineered <i>Lactobacillus casei</i> targets the IgT-pIgR axis to confer mucosal protection against <i>Aeromonas veronii</i> in snakehead (<i>Channa argus</i>).
- 2026-03-23
- Frontiers in immunology 17
- Kui-Peng Gao
- Jian-Ran Dou
- Bing-Bing Ma
- Tian-Bao Ma
- Na Li
- Ai-Dong Qian
- Xiao-Feng Shan
- Wu-Wen Sun
- Lei Zhang
- Di Zhang
- Chun-Feng Wang
- Dong-Xing Zhang
- PubMed: 41948342
- DOI: 10.3389/fimmu.2026.1759765
Introduction
Aeromonas veronii remains a pervasive aquatic pathogen precipitating catastrophic economic depletion and threats to global food security. Conventional therapeutic modalities are constrained by inadequate stability, prohibitive costs, and biosafety risks.Methods
To address such challenges, an engineered Lactobacillus casei strain was developed to constitutively express the A. veronii outer membrane protein OmpAI through a tandem promoter system to ensure optimized antigen delivery.Results
Anal intubation with engineered L. casei in Channa argus stimulated compartmentalized mucosal immunity, evidenced by a six-fold elevation in hindgut IgT transcripts, significant infiltration of IgT+ B cells, and pIgR mediated transcytosis, synchronized with systemic IgM activation. The probiotic treament accelerated pathogen clearance, improved survival rates to 42.9% compared to 12.5% in control group, and reorganized the commensal microbiome through a specific enrichment of beneficial Firmicutes.Discussion
This study elucidated a novel engineered-probiotic mucosal vaccination strategy for teleosts, providing a noninvasive, mucosal targeted immunoprophylactic strategy to decrease antibiotic dependency in aquaculture.Research Insights
| Supplement | Health Outcome | Effect Type | Effect Size |
|---|---|---|---|
| Lactobacillus casei Lc-11 | Enhanced Mucosal Immune Response | Beneficial | Large |
| Lactobacillus casei Lc-11 | Improved Mucosal Immunity | Beneficial | Large |
| Lactobacillus casei Lc-11 | Improved Survival | Beneficial | Large |