治療物質を分泌するスマート微生物を開発(Smart Microbes Use Pathogenic Tools to Deliver Therapeutics)

2025-06-03 タフツ大学

<関連情報>

• https://now.tufts.edu/2025/06/03/smart-microbes-use-pathogenic-tools-deliver-therapeutics
• https://www.cell.com/cell-host-microbe/fulltext/S1931-3128(23)00111-7
• https://academic.oup.com/pnasnexus/article/3/9/pgae374/7747221

腸管内で治療用ナノボディをその場で分泌するための遺伝子組み換え大腸菌 Engineered Escherichia coli for the in situ secretion of therapeutic nanobodies in the gut

Jason P. Lynch ∙ Coral González-Prieto^, ∙ Analise Z. Reeves ∙ … ∙ Charles B. Shoemaker ∙ Wendy S. Garrett ∙ Cammie F. Lesser
Cell Host & Microbe  Published:March 31, 2023
DOI:https://doi.org/10.1016/j.chom.2023.03.007

Graphical abstract

Highlights

• Engineering of PROT₃EcT, E. coli outfitted with a programmable protein secretion system
• PROT₃EcT secrete functional nanobodies into their surroundings
• Pretreating with anti-TNF-α-secreting PROT₃EcT limits colitis in a preclinical IBD model

Summary

Drug platforms that enable the directed delivery of therapeutics to sites of diseases to maximize efficacy and limit off-target effects are needed. Here, we report the development of PROT₃EcT, a suite of commensal Escherichia coli engineered to secrete proteins directly into their surroundings. These bacteria consist of three modular components: a modified bacterial protein secretion system, the associated regulatable transcriptional activator, and a secreted therapeutic payload. PROT₃EcT secrete functional single-domain antibodies, nanobodies (Nbs), and stably colonize and maintain an active secretion system within the intestines of mice. Furthermore, a single prophylactic dose of a variant of PROT₃EcT that secretes a tumor necrosis factor-alpha (TNF-α)-neutralizing Nb is sufficient to ablate pro-inflammatory TNF levels and prevent the development of injury and inflammation in a chemically induced model of colitis. This work lays the foundation for developing PROT₃EcT as a platform for the treatment of gastrointestinal-based diseases.

人工的に作られた常在微生物によるナノボディの原位置沈着は、腸管出血性大腸菌のマウスモデルにおける生存を促進する In situ deposition of nanobodies by an engineered commensal microbe promotes survival in a mouse model of enterohemorrhagic E. coli

Rajkamal Srivastava , Coral González-Prieto , Jason P Lynch , Michele E Muscolo , Catherine Y Lin , Markus A Brown , Luisa Lemos , Anishma Shrestha , Marcia S Osburne , John M Leong …
PNAS Nexus  Published:02 September 2024
DOI:https://doi.org/10.1093/pnasnexus/pgae374

Abstract

Engineered smart microbes that deliver therapeutic payloads are emerging as treatment modalities, particularly for diseases with links to the gastrointestinal tract. Enterohemorrhagic Escherichia coli (EHEC) is a causative agent of potentially lethal hemolytic uremic syndrome. Given concerns that antibiotic treatment increases EHEC production of Shiga toxin (Stx), which is responsible for systemic disease, novel remedies are needed. EHEC encodes a type III secretion system (T3SS) that injects Tir into enterocytes. Tir inserts into the host cell membrane, exposing an extracellular domain that subsequently binds intimin, one of its outer membrane proteins, triggering the formation of attaching and effacing (A/E) lesions that promote EHEC mucosal colonization. Citrobacter rodentium (Cr), a natural A/E mouse pathogen, similarly requires Tir and intimin for its pathogenesis. Mice infected with Cr(ΦStx2dact), a variant lysogenized with an EHEC-derived phage that produces Stx2dact, develop intestinal A/E lesions and toxin-dependent disease. Stx2a is more closely associated with human disease. By developing an efficient approach to seamlessly modify the C. rodentium genome, we generated Cr_Tir-M^EHEC(ΦStx2a), a variant that expresses Stx2a and the EHEC extracellular Tir domain. We found that mouse precolonization with HS-PROT₃EcT-TD4, a human commensal E. coli strain (E. coli HS) engineered to efficiently secrete an anti-EHEC Tir nanobody, delayed bacterial colonization and improved survival after challenge with Cr_Tir-M^EHEC(ΦStx2a). This study suggests that commensal E. coli engineered to deliver payloads that block essential virulence determinants can be developed as a new means to prevent and potentially treat infections including those due to antibiotic resistant microbes.