Work

Construction of Recombinant Mycobacterium smegmatis Expressing the Pro-Apoptotic Protein BIK and Its Impact on Macrophage Apoptosis

Year: 2026

Type: article

Abstract: Tuberculosis (TB), caused by Mycobacterium tuberculosis, remains a major global health threat. A key virulence mechanism involves the pathogen’s ability to inhibit apoptosis in infected macrophages, thereby facilitating immune evasion and persistent infection. The pro-apoptotic protein Bcl-2-interacting killer (BIK) represents a critical mediator of macrophage apoptosis. In this study, we engineered a recombinant Mycobacterium smegmatis strain (rMs-BIK) designed to secrete BIK via fusion with the Ag85B signal peptide (ASP). Secretion and expression of the BIK protein were confirmed by Western blotting. Quantitative flow cytometric analysis revealed that rMs-BIK induced significant apoptosis in RAW264.7 macrophages, with rates of 14.49%, 14.22%, and 22.24% at 12, 24, and 48 h post-infection, respectively. These values were markedly higher than those observed in cells infected with the wild-type strain (7.68%, 9.24%, and 10.90%) or the empty vector control (8.80%, 11.19%, and 14.43%). Our findings demonstrate the feasibility of functional pro-apoptotic protein delivery using a mycobacterial vector, providing a robust foundation for the future development of recombinant BCG-based vaccine candidates.

Source: Pathogens

DOI: 10.3390/pathogens15080857

Authors: Yaning Pang, Jing Bi

Institutions: Southern University of Science and Technology, Shenzhen Third People’s Hospital

Language: English

Topic: Tuberculosis Research and Epidemiology

Subfield: Infectious Diseases

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: gold

Estimated APC paid: $2,654