Subcellular Localization Dictates Therapeutic Function: Spatially Targeted Delivery of Amuc_1100 by Engineered...

Area of Science:

• Microbiome research
• Gastroenterology
• Genetic engineering

Background:

• Impaired intestinal barrier function is a key feature of inflammatory bowel disease (IBD).
• Akkermansia muciniphila and its protein Amuc_1100 can strengthen the intestinal barrier.
• Clinical use of Amuc_1100 is hindered by the difficulty in culturing A. muciniphila.

Purpose of the Study:

• To engineer the probiotic Lacticaseibacillus paracasei L9 for expressing Amuc_1100.
• To evaluate the therapeutic potential of engineered Lc. paracasei L9 strains in models of IBD.
• To determine how subcellular localization of Amuc_1100 influences therapeutic effects.

Main Methods:

• Engineered Lc. paracasei L9 strains for intracellular, secretory, and surface-display of Amuc_1100.
• Assessed efficacy in LPS-stimulated macrophages and a DSS-induced colitis mouse model.
• Evaluated inflammation, barrier integrity, and mucosal repair markers.

Main Results:

• Secretory (pUA-L9) and surface-displayed (pUPA-L9) strains suppressed pro-inflammatory cytokines in macrophages.
• Both engineered strains alleviated colitis in mice, outperforming native A. muciniphila.
• pUA-L9 acted as a systemic immunomodulator, while pUPA-L9 enhanced local barrier repair and mucus production.

Conclusions:

• Subcellular localization of Amuc_1100 in engineered probiotics dictates therapeutic action.
• Secretory and surface-displayed Amuc_1100 provide complementary effects for IBD treatment.
• This approach offers a novel strategy for precision microbiome therapy in IBD.