1
|
Comprehensive Analysis of the Nocardia cyriacigeorgica Complex Reveals Five Species-Level Clades with Different Evolutionary and Pathogenicity Characteristics. mSystems 2022; 7:e0140621. [PMID: 35430877 PMCID: PMC9239197 DOI: 10.1128/msystems.01406-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Nocardia cyriacigeorgica is a common etiological agent of nocardiosis that has increasingly been implicated in serious pulmonary infections, especially in immunocompromised individuals. However, the evolution, diversity, and pathogenesis of N. cyriacigeorgica have remained unclear. Here, we performed a comparative genomic analysis using 91 N. cyriacigeorgica strains, 45 of which were newly sequenced in this study. Phylogenetic and average nucleotide identity (ANI) analyses revealed that N. cyriacigeorgica contained five species-level clades (8.6 to 14.6% interclade genetic divergence), namely, the N. cyriacigeorgica complex (NCC). Further pan-genome analysis revealed extensive differences among the five clades in nine functional categories, such as energy production, lipid metabolism, secondary metabolites, and signal transduction mechanisms. All 2,935 single-copy core genes undergoing purifying selection were highly conserved across NCC. However, clades D and E exhibited reduced selective constraints, compared to clades A to C. Horizontal gene transfer (HGT) and mobile genetic elements contributed to genomic plasticity, and clades A and B had experienced a higher level of HGT events than other clades. A total of 129 virulence factors were ubiquitous across NCC, such as the mce operon, hemolysin, and type VII secretion system (T7SS). However, different distributions of three toxin-coding genes and two new types of mce operons were detected, which might contribute to pathogenicity differences among the members of the NCC. Overall, our study provides comprehensive insights into the evolution, genetic diversity, and pathogenicity of NCC, facilitating the prevention of infections. IMPORTANCENocardia species are opportunistic bacterial pathogens that can affect all organ systems, primarily the skin, lungs, and brain. N. cyriacigeorgica is the most prevalent species within the genus, exhibits clinical significance, and can cause severe infections when disseminated throughout the body. However, the evolution, diversity, and pathogenicity of N. cyriacigeorgica remain unclear. Here, we have conducted a comparative genomic analysis of 91 N. cyriacigeorgica strains and revealed that N. cyriacigeorgica is not a single species but is composed of five closely related species. In addition, we discovered that these five species differ in many ways, involving selection pressure, horizontal gene transfer, functional capacity, pathogenicity, and antibiotic resistance. Overall, our work provides important clues in dissecting the evolution, genetic diversity, and pathogenicity of NCC, thereby advancing prevention measures against these infections.
Collapse
|
2
|
Ji X, Zhang X, Sun L, Hou X, Song J, Tan X, Song H, Qiu X, Li M, Tang L, Han L, Li Z. Mce1C and Mce1D facilitate N. farcinica invasion of host cells and suppress immune responses by inhibiting innate signaling pathways. Sci Rep 2020; 10:14908. [PMID: 32913259 PMCID: PMC7484815 DOI: 10.1038/s41598-020-71860-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 08/06/2020] [Indexed: 11/22/2022] Open
Abstract
The mammalian cell entry (Mce) family of proteins consists of invasin-like membrane-associated proteins. The roles of Mce1C and Mce1D proteins in host–pathogen interactions have not been investigated. In this study, we demonstrate that Mce1C and Mce1D protein is localized in the cell wall fraction of N. farcinica. Both N. farcinica Mce1C and Mce1D proteins are expressed at the level of protein and mRNA and elicit antibody responses during infection. Mce1C and Mce1D facilitate the internalization of Escherichia coli expressing Mce1C protein or latex beads coated with Mce1D protein by HeLa cells, respectively. We further demonstrate that Mce1C and Mce1D can suppress the secretion of the proinflammatory factors TNF-α and IL-6 in macrophages infected with Mycobacterium smegmatis expressing Mce1C or Mce1D and promote the survival of M. smegmatis expressing Mce1C or Mce1D in macrophages. In addition, Mce1C and Mce1D supress the activation of the NF-κB and MAPK signaling pathways by blocking the phosphorylation of AKT, P65, ERK1/2, JNK, or P38 in macrophages. These findings suggest that Mce1C and Mce1D proteins facilitate N. farcinica invasion of HeLa cells and suppress host innate immune responses by manipulating NF-κB and MAPK signaling pathways, which may provide a target for N. farcinica treatment.
Collapse
Affiliation(s)
- Xingzhao Ji
- Shandong Academy of Clinical Medicine, Provincial Hospital Affiliated to Shandong First Medical University, Jinan, 250000, China.,State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, 155 Changbai Road Changping District, Beijing, 102206, China
| | - Xiujuan Zhang
- Department of Endocrinology, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China
| | - Lina Sun
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, 155 Changbai Road Changping District, Beijing, 102206, China
| | - Xuexin Hou
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, 155 Changbai Road Changping District, Beijing, 102206, China
| | - Jingdong Song
- National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Xiaoluo Tan
- Chenzhou Center for Disease Control and Prevention, Chenzhou, China
| | - Han Song
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, 155 Changbai Road Changping District, Beijing, 102206, China
| | - Xiaotong Qiu
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, 155 Changbai Road Changping District, Beijing, 102206, China
| | - Minghui Li
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, 155 Changbai Road Changping District, Beijing, 102206, China
| | - Lu Tang
- First Affiliated Hospital of Chengdu Medical College, Chengdu, China
| | - Lichao Han
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, 155 Changbai Road Changping District, Beijing, 102206, China
| | - Zhenjun Li
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, 155 Changbai Road Changping District, Beijing, 102206, China.
| |
Collapse
|
3
|
Nfa34810 Facilitates Nocardia farcinica Invasion of Host Cells and Stimulates Tumor Necrosis Factor Alpha Secretion through Activation of the NF-κB and Mitogen-Activated Protein Kinase Pathways via Toll-Like Receptor 4. Infect Immun 2020; 88:IAI.00831-19. [PMID: 31964749 PMCID: PMC7093121 DOI: 10.1128/iai.00831-19] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 01/06/2020] [Indexed: 11/21/2022] Open
Abstract
The mechanism underlying the pathogenesis of Nocardia is not fully known. The Nfa34810 protein of Nocardia farcinica has been predicted to be a virulence factor. However, relatively little is known regarding the interaction of Nfa34810 with host cells, specifically invasion and innate immune activation. In this study, we aimed to determine the role of recombinant Nfa34810 during infection. We demonstrated that Nfa34810 is an immunodominant protein located in the cell wall. The mechanism underlying the pathogenesis of Nocardia is not fully known. The Nfa34810 protein of Nocardia farcinica has been predicted to be a virulence factor. However, relatively little is known regarding the interaction of Nfa34810 with host cells, specifically invasion and innate immune activation. In this study, we aimed to determine the role of recombinant Nfa34810 during infection. We demonstrated that Nfa34810 is an immunodominant protein located in the cell wall. Nfa34810 protein was able to facilitate the uptake and internalization of latex beads coated with Nfa34810 protein into HeLa cells. Furthermore, the deletion of the nfa34810 gene in N. farcinica attenuated the ability of the bacteria to infect both HeLa and A549 cells. Moreover, stimulation with Nfa34810 triggered macrophages to produce tumor necrosis factor alpha (TNF-α), and it also activated mitogen-activated protein kinase (MAPK) and nuclear factor κB (NF-κB) signaling pathways by inducing the phosphorylation of ERK1/2, p38, JNK, p65, and AKT in macrophages. Specific inhibitors of ERK1/2, JNK, and NF-κB significantly reduced the expression of TNF-α, which demonstrated that Nfa34810-mediated TNF-α production was dependent upon the activation of these kinases. We further found that neutralizing antibodies against Toll-like receptor 4 (TLR4) significantly inhibited TNF-α secretion. Taken together, our results indicated that Nfa34810 is a virulence factor of N. farcinica and plays an important role during infection. Nfa34810-induced production of TNF-α in macrophages also involves ERK, JNK, and NF-κB via the TLR4 pathway.
Collapse
|
4
|
Ji X, Zhang X, Sun L, Hou X, Song H, Han L, Xu S, Li H, Qiu X, Li M, Wang X, Zheng N, Li Z. The Heparin-Binding Hemagglutinin of Nocardia cyriacigeorgica GUH-2 Stimulates Inflammatory Cytokine Secretion Through Activation of Nuclear Factor κB and Mitogen-Activated Protein Kinase Pathways via TLR4. Front Cell Infect Microbiol 2020; 10:3. [PMID: 32117792 PMCID: PMC7031410 DOI: 10.3389/fcimb.2020.00003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Accepted: 01/07/2020] [Indexed: 01/14/2023] Open
Abstract
Heparin-binding hemagglutinin (HBHA) from mycobacteria is involved in the dissemination of infection and the activation of the host immune response. However, the interaction of Nocardia cyriacigeorgica HBHA with the host cells remains unknown. In the present study, we describe N. cyriacigeorgica HBHA interactions with epithelial cells and organ colonization. We then investigate the mechanisms by which HBHA induces the production of inflammatory cytokines in macrophages. Immunofluorescent microscopy showed that HBHA adhered to A549 cells and HeLa cells and that the C-terminal fragment, which contains a Pro-Ala-Lys–rich domain, was responsible for adhesion. The deletion of the hbha gene in N. cyriacigeorgica mutant strains impaired adhesion to A549 cells and HeLa cells. In addition, the HBHA protein activated the mitogen-activated protein kinase (MAPK) and nuclear factor kappa B (NF-κB) signaling pathways and promoted the production of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and IL-10 in macrophages. HBHA-mediated TNF-α production was dependent on the activation of the c-Jun N-terminal kinase (JNK) signal pathways, and the IL-6 and IL-10 production was dependent on the activation of extracellular regulated kinase (ERK) 1/2, MAPK p38 (p38), JNK, and nuclear NF-κB signaling pathways. Additionally, the HBHA-mediated activation of innate immunity was dependent on Toll-like receptor 4 (TLR4). Taken together, these results indicate that N. cyriacigeorgica HBHA not only adheres to epithelial cells and may be involved in organ colonization, but also plays a critical role in the modulation of innate immunity through the MAPK and NF-κB signaling pathways via TLR4.
Collapse
Affiliation(s)
- Xingzhao Ji
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Xiujuan Zhang
- Department of Endocrinology, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China
| | - Lina Sun
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Xuexin Hou
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Han Song
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.,School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China
| | - Lichao Han
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.,Department of Medicine, Tibet University, Lhasa, China
| | - Shuai Xu
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Heqiao Li
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Xiaotong Qiu
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Minghui Li
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Xuebing Wang
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Ningwei Zheng
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.,School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China
| | - Zhenjun Li
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| |
Collapse
|