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Zhai Z, Xiong Y, Gu Y, Lei Y, An H, Yi H, Zhao L, Ren F, Hao Y. Up-regulation of sortase-dependent pili in Bifidobacterium longum BBMN68 in response to bile stress enhances its adhesion to HT-29 cells. Int J Biol Macromol 2024; 257:127527. [PMID: 37866558 DOI: 10.1016/j.ijbiomac.2023.127527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 10/14/2023] [Accepted: 10/16/2023] [Indexed: 10/24/2023]
Abstract
Adhesion to gastrointestinal tract is crucial for bifidobacteria to exert their probiotic effects. Our previous work found that bile salts significantly enhance the adhesion ability of Bifidobacterium longum BBMN68 to HT-29 cells. In this study, trypsin-shaving and LC-MS/MS-based surface proteomics were employed to identify surface proteins involved in bile stress response. Among the 829 differentially expressed proteins, 56 up-regulated proteins with a fold change >1.5 were subjected to further analysis. Notably, the minor pilin subunit FimB was 4.98-fold up-regulated in response to bile stress. In silico analysis and RT-PCR confirmed that gene fimB, fimA and srtC were co-transcribed and contributed to the biosynthesis of sortase-dependent pili Pil1. Moreover, scanning electron microscopy and immunogold electron microscopy assays showed increased abundance and length of Pil1 on BBMN68 under bile stress. As the major pilin subunit FimA serves as adhesion component of Pil1, an inhibition assay using anti-FimA antibodies further confirmed the critical role of Pil1 in mediating the adhesion of BBMN68 to HT-29 cells under bile stress. Our findings suggest that the up-regulation of Pil1 in response to bile stress enhances the adhesion of BBMN68 to intestinal epithelial cells, highlighting a novel mechanism of gut persistence in B. longum strains.
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Affiliation(s)
- Zhengyuan Zhai
- Key Laboratory of Functional Dairy, Co-constructed by Ministry of Education and Beijing Municipality, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China; Food Laboratory of Zhongyuan, Luohe 462300, Henan, China
| | - Yao Xiong
- Key Laboratory of Functional Dairy, Co-constructed by Ministry of Education and Beijing Municipality, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China
| | - Yaxin Gu
- Key Laboratory of Functional Dairy, Co-constructed by Ministry of Education and Beijing Municipality, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China
| | - Yuanqiu Lei
- Key Laboratory of Functional Dairy, Co-constructed by Ministry of Education and Beijing Municipality, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China
| | - Haoran An
- Center for Infectious Disease Research, Tsinghua-Peking Joint Center for Life Science, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Huaxi Yi
- Food Laboratory of Zhongyuan, Luohe 462300, Henan, China; College of Food Science and Engineering, Ocean University of China, Qingdao 266100, Shandong, China
| | - Liang Zhao
- Key Laboratory of Functional Dairy, Co-constructed by Ministry of Education and Beijing Municipality, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China
| | - Fazheng Ren
- Key Laboratory of Precision Nutrition and Food Quality, Department of Nutrition and Health, China Agricultural University, Beijing 100093, China
| | - Yanling Hao
- Key Laboratory of Precision Nutrition and Food Quality, Department of Nutrition and Health, China Agricultural University, Beijing 100093, China; Food Laboratory of Zhongyuan, Luohe 462300, Henan, China.
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Solis N, Cordwell SJ. Cell Shaving and False-Positive Control Strategies Coupled to Novel Statistical Tools to Profile Gram-Positive Bacterial Surface Proteomes. Methods Mol Biol 2016; 1440:47-55. [PMID: 27311663 DOI: 10.1007/978-1-4939-3676-2_4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
A powerful start to the discovery and design of novel vaccines, and for better understanding of host-pathogen interactions, is to profile bacterial surfaces using the proteolytic digestion of surface-exposed proteins under mild conditions. This "cell shaving" approach has the benefit of both identifying surface proteins and their surface-exposed epitopes, which are those most likely to interact with host cells and/or the immune system, providing a comprehensive overview of bacterial cell topography. An essential requirement for successful cell shaving is to account for (or minimize) cellular lysis that can occur during the shaving procedure and thus generate data that is biased towards non-surface (e.g., cytoplasmic) proteins. This is further complicated by the presence of "moonlighting" proteins, which are proteins predicted to be intracellular but with validated surface or extracellular functions. Here, we describe an optimized cell shaving protocol for Gram-positive bacteria that uses proteolytic digestion and a "false-positive" control to reduce the number of intracellular contaminants in these datasets. Released surface-exposed peptides are analyzed by liquid chromatography (LC) coupled to high-resolution tandem mass spectrometry (MS/MS). Additionally, the probabilities of proteins being surface exposed can be further calculated by applying novel statistical tools.
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Affiliation(s)
- Nestor Solis
- School of Molecular Bioscience, The University of Sydney, Sydney, NSW, Australia
- Department of Oral Biological and Medical Sciences, Centre for Blood Research, University of British Columbia, Vancouver, BC, Canada
| | - Stuart J Cordwell
- School of Molecular Bioscience, The University of Sydney, Sydney, NSW, Australia.
- Discipline of Pathology, School of Medical Sciences, The University of Sydney, The Hub Building D17, Sydney, NSW, 2006, Australia.
- Charles Perkins Centre, The University of Sydney, Sydney, NSW, Australia.
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