1
|
Ning H, Liang X, Xie Y, Bai L, Zhang W, Wang L, Kang J, Lu Y, Ma Y, Bai G, Bai Y. c-di-AMP Accumulation Regulates Growth, Metabolism, and Immunogenicity of Mycobacterium smegmatis. Front Microbiol 2022; 13:865045. [PMID: 35685938 PMCID: PMC9171234 DOI: 10.3389/fmicb.2022.865045] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Accepted: 04/14/2022] [Indexed: 11/13/2022] Open
Abstract
Cyclic dimeric adenosine monophosphate (c-di-AMP) is a ubiquitous second messenger of bacteria involved in diverse physiological processes as well as host immune responses. MSMEG_2630 is a c-di-AMP phosphodiesterase (cnpB) of Mycobacterium smegmatis, which is homologous to Mycobacterium tuberculosis Rv2837c. In this study, cnpB-deleted (ΔcnpB), -complemented (ΔcnpB::C), and -overexpressed (ΔcnpB::O) strains of M. smegmatis were constructed to investigate the role of c-di-AMP in regulating mycobacterial physiology and immunogenicity. This study provides more precise evidence that elevated c-di-AMP level resulted in smaller colonies, shorter bacteria length, impaired growth, and inhibition of potassium transporter in M. smegmatis. This is the first study to report that elevated c-di-AMP level could inhibit biofilm formation and induce porphyrin accumulation in M. smegmatis by regulating associated gene expressions, which may have effects on drug resistance and virulence of mycobacterium. Moreover, the cnpB-deleted strain with an elevated c-di-AMP level could induce enhanced Th1 immune responses after M. tuberculosis infection. Further, the pathological changes and the bacteria burden in ΔcnpB group were comparable with the wild-type M. smegmatis group against M. tuberculosis venous infection in the mouse model. Our findings enhanced the understanding of the physiological role of c-di-AMP in mycobacterium, and M. smegmatis cnpB-deleted strain with elevated c-di-AMP level showed the potential for a vaccine against tuberculosis.
Collapse
Affiliation(s)
- Huanhuan Ning
- Department of Microbiology and Pathogen Biology, Air Force Medical University, Xi’an, China
| | - Xuan Liang
- Department of Microbiology and Pathogen Biology, Air Force Medical University, Xi’an, China
- College of Life Sciences, Northwest University, Xi’an, China
| | - Yanling Xie
- Department of Microbiology and Pathogen Biology, Air Force Medical University, Xi’an, China
- School of Life Sciences, Yan’an University, Yan’an, China
| | - Lu Bai
- Department of Microbiology and Pathogen Biology, Air Force Medical University, Xi’an, China
- School of Life Sciences, Yan’an University, Yan’an, China
| | - Wei Zhang
- Department of Pediatrics, Tangdu Hospital, Air Force Medical University, Xi’an, China
| | - Lifei Wang
- Graduate School, Chang’an University, Xi’an, China
| | - Jian Kang
- Department of Microbiology and Pathogen Biology, Air Force Medical University, Xi’an, China
| | - Yanzhi Lu
- Department of Microbiology and Pathogen Biology, Air Force Medical University, Xi’an, China
| | - Yanling Ma
- College of Life Sciences, Northwest University, Xi’an, China
| | - Guangchun Bai
- Department of Immunology and Microbial Disease, Albany Medical College, Albany, NY, United States
- *Correspondence: Guangchun Bai,
| | - Yinlan Bai
- Department of Microbiology and Pathogen Biology, Air Force Medical University, Xi’an, China
- Yinlan Bai,
| |
Collapse
|
2
|
Dokic A, Peterson E, Arrieta-Ortiz ML, Pan M, Di Maio A, Baliga N, Bhatt A. Mycobacterium abscessus biofilms produce an extracellular matrix and have a distinct mycolic acid profile. Cell Surf 2021; 7:100051. [PMID: 33912773 PMCID: PMC8066798 DOI: 10.1016/j.tcsw.2021.100051] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 03/25/2021] [Accepted: 03/26/2021] [Indexed: 02/06/2023] Open
Abstract
A non-tuberculous mycobacterium, Mycobacterium abscessus is an emerging opportunistic pathogen associated with difficult to treat pulmonary infections, particularly in patients suffering from cystic fibrosis. It is capable of forming biofilms in vitro that result in an increase of already high levels of antibiotic resistance in this bacterium. Evidence that M. abscessus forms biofilm-like microcolonies in patient lungs and on medical devices further implicated the need to investigate this biofilm in detail. Therefore, in this study we characterized the M. abscessus pellicular biofilm, formed on a liquid-air interface, by studying its molecular composition, and its transcriptional profile in comparison to planktonic cells. Using scanning electron micrographs and fluorescence microscopy, we showed that M. abscessus biofilms produce an extracellular matrix composed of lipids, proteins, carbohydrates and extracellular DNA. Transcriptomic analysis of biofilms revealed an upregulation of pathways involved in the glyoxylate shunt, redox metabolism and mycolic acid biosynthesis. Genes involved in elongation and desaturation of mycolic acids were highly upregulated in biofilms and, mirroring those findings, biochemical analysis of mycolates revealed molecular changes and an increase in mycolic acid chain length. Together these results give us an insight into the complex structure of M. abscessus biofilms, the understanding of which may be adapted for clinical use in treatment of biofilm infections, including strategies for dispersing the extracellular matrix, allowing antibiotics to gain access to bacteria within the biofilm.
Collapse
Affiliation(s)
- Anja Dokic
- School of Biosciences and Institute of Microbiology and Infection, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | | | | | - Min Pan
- Institute for Systems Biology, Seattle, WA 98109 USA
| | - Alessandro Di Maio
- School of Biosciences and Institute of Microbiology and Infection, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - Nitin Baliga
- Institute for Systems Biology, Seattle, WA 98109 USA
| | - Apoorva Bhatt
- School of Biosciences and Institute of Microbiology and Infection, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| |
Collapse
|
3
|
Veyron-Churlet R, Saliou JM, Locht C. Interconnection of the mycobacterial heparin-binding hemagglutinin with cholesterol degradation and heme/iron pathways identified by proximity-dependent biotin identification in Mycobacterium smegmatis. Environ Microbiol 2021; 23:3212-3224. [PMID: 33913567 DOI: 10.1111/1462-2920.15547] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 04/15/2021] [Accepted: 04/26/2021] [Indexed: 11/28/2022]
Abstract
Deciphering protein-protein interactions is a critical step in the identification and the understanding of biological mechanisms deployed by pathogenic bacteria. The development of in vivo technologies to characterize these interactions is still in its infancy, especially for bacteria whose subcellular organization is particularly complex, such as mycobacteria. In this work, we used the proximity-dependent biotin identification (BioID) to define the mycobacterial heparin-binding hemagglutinin (HbhA) interactome in the saprophytic bacterium Mycobacterium smegmatis. M. smegmatis is a commonly used model to study and characterize the physiology of pathogenic mycobacteria, such as Mycobacterium tuberculosis. Here, we adapted the BioID technology to in vivo protein-protein interactions studies in M. smegmatis, which presents several advantages, such as maintaining the complex organization of the mycomembrane, offering the possibility to study membrane or cell wall-associated proteins, including HbhA, in the presence of cofactors and post-translational modifications, such as the complex methylation pattern of HbhA. Using this technology, we found that HbhA is interconnected with cholesterol degradation and heme/iron pathways. These results are in line with previous studies showing the dual localization of HbhA, associated with the cell wall and intracytoplasmic lipid inclusions, and its induction under high iron growth conditions.
Collapse
Affiliation(s)
- Romain Veyron-Churlet
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019 - UMR 9017 - CIIL - Center for Infection and Immunity of Lille, Lille, F-59000, France
| | - Jean-Michel Saliou
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, US 41 - UMS 2014 - PLBS, Lille, F-59000, France
| | - Camille Locht
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019 - UMR 9017 - CIIL - Center for Infection and Immunity of Lille, Lille, F-59000, France
| |
Collapse
|