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Xu N, Fan L, Li L, Guo Y. Exploring the pathogenicity of Mycoplasma pneumoniae: Focus on community-acquired respiratory distress syndrome toxins. Microb Pathog 2024; 195:106865. [PMID: 39153578 DOI: 10.1016/j.micpath.2024.106865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Revised: 08/12/2024] [Accepted: 08/14/2024] [Indexed: 08/19/2024]
Abstract
Community-Acquired Respiratory Distress Syndrome Toxin (CARDS TX) is a unique exotoxin produced by Mycoplasma pneumoniae (MP) and has been confirmed to possess ADP-ribosyltransferase (ART) and vacuolating activities. CARDS TX binds to receptors on the surfaces of mammalian cells followed by entry into the cells through clathrin-mediated endocytosis, and exerts cytotoxic effects by undergoing retrograde transport and finally cleavage on endosomes and cellular organelles. In addition, CARDS TX can trigger severe inflammatory reactions resulting in airway dysfunction, producing allergic inflammation and asthma-like conditions. As a newly discovered virulence factor of MP, CARDS TX has been extensively studied in recent years. As resistance to macrolide drugs has increased significantly in recent years and there is no vaccine against MP, the development of a vaccine targeting CARDS TX is considered a potential preventive measure. This review focuses on recent studies and insights into this toxin, providing directions for a better understanding of MP pathogenesis and treatment. IMPORTANCE: A serious hazard to worldwide public health in recent years, Mycoplasma pneumoniae (MP) is a prominent bacterium that causes community-acquired pneumonia (CAP) in hospitalized children. Due to their high prevalence and fatality rates, MP infections often cause both respiratory illnesses and extensive extrapulmonary symptoms. It has recently been shown that MP produces a distinct exotoxin known as Community-Acquired Respiratory Distress Syndrome Toxin (CARDS TX). Mycoplasma pneumoniae pneumonia (MPP)-like tissue injury is caused by this toxin because it has both ADP-ribosyltransferase and vacuolating properties. A better knowledge of MP etiology and therapy is provided by this review, which focuses on latest research and insights into this toxin.
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Affiliation(s)
- Nuo Xu
- Department of Respiratory Medicine, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi Children's Hospital, Wuxi, 214000, China
| | - Lu Fan
- Department of Respiratory Medicine & Clinical Allergy Center, Affiliated Children's Hospital of Jiangnan University (Wuxi Children's Hospital), Wuxi, 214000, China
| | - Ling Li
- Department of Respiratory Medicine, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi Children's Hospital, Wuxi, 214000, China; Department of Respiratory Medicine & Clinical Allergy Center, Affiliated Children's Hospital of Jiangnan University (Wuxi Children's Hospital), Wuxi, 214000, China.
| | - Yun Guo
- Department of Respiratory Medicine, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi Children's Hospital, Wuxi, 214000, China; Department of Respiratory Medicine & Clinical Allergy Center, Affiliated Children's Hospital of Jiangnan University (Wuxi Children's Hospital), Wuxi, 214000, China.
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Georgakopoulou VE, Lempesis IG, Sklapani P, Trakas N, Spandidos DA. Exploring the pathogenetic mechanisms of Mycoplasmapneumoniae (Review). Exp Ther Med 2024; 28:271. [PMID: 38765654 PMCID: PMC11097136 DOI: 10.3892/etm.2024.12559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2023] [Accepted: 04/17/2024] [Indexed: 05/22/2024] Open
Abstract
Mycoplasmas, the smallest self-replicating prokaryotes without a cell wall, are the most prevalent and extensively studied species in humans. They significantly contribute to chronic respiratory tract illnesses and pneumonia, with children and adolescents being particularly vulnerable. Mycoplasma pneumoniae (M. pneumoniae) infections typically tend to be self-limiting and mild but can progress to severe or even life-threatening conditions in certain individuals. Extrapulmonary effects often occur without pneumonia, and both intrapulmonary and extrapulmonary complications operate through separate pathological mechanisms. The indirect immune-mediated damage of the immune system, vascular blockages brought on by vasculitis or thrombosis and direct harm from invasion or locally induced inflammatory cytokines are potential causes of extrapulmonary manifestations due to M. pneumoniae. Proteins associated with adhesion serve as the primary factor crucial for the pathogenicity of M. pneumoniae, relying on a specialized polarized terminal attachment organelle. The type and density of these host receptors significantly impact the adhesion and movement of M. pneumoniae, subsequently influencing the pathogenic mechanism and infection outcomes. Adjacent proteins are crucial for the proper assembly of the attachment organelle, with variations in the genetic domains of P1, P40 and P90 surfaces contributing to the variability of clinical symptoms and offering new avenues for developing vaccines against M. pneumoniae infections. M. pneumoniae causes oxidative stress within respiratory tract epithelial cells by adhering to host cells and releasing hydrogen peroxide and superoxide radicals. This oxidative stress enhances the vulnerability of host cells to harm induced by oxygen molecules. The lack of superoxide dismutase and catalase of bacteria allows it to hinder the catalase activity of the host cell, leading to the reduced breakdown of peroxides. Lung macrophages play a significant role in managing M. pneumoniae infection, identifying it via Toll-like receptor 2 and initiating the myeloid differentiation primary response gene 88-nuclear factor κΒ signaling cascade. However, the precise mechanisms enabling M. pneumoniae to evade intracellular host defenses remain unknown, necessitating further exploration of the pathways involved in intracellular survival. The present comprehensive review delves into the pathogenesis of M. pneumoniae infection within the pulmonary system and into extrapulmonary areas, outlining its impact.
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Affiliation(s)
- Vasiliki Epameinondas Georgakopoulou
- Department of Pathophysiology, Laiko General Hospital, National and Kapodisttrian University of Athens, 11527 Athens, Greece
- Department of Infectious Diseases-COVID-19 Unit, Laiko General Hospital, 11527 Athens, Greece
| | - Ioannis G. Lempesis
- Department of Pathophysiology, Laiko General Hospital, National and Kapodisttrian University of Athens, 11527 Athens, Greece
| | - Pagona Sklapani
- Department of Biochemistry, Sismanogleio Hospital, 15126 Athens, Greece
| | - Nikolaos Trakas
- Department of Biochemistry, Sismanogleio Hospital, 15126 Athens, Greece
| | - Demetrios A. Spandidos
- Laboratory of Clinical Virology, School of Medicine, University of Crete, 71003 Heraklion, Greece
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Insight into the Pathogenic Mechanism of Mycoplasma pneumoniae. Curr Microbiol 2023; 80:14. [PMID: 36459213 PMCID: PMC9716528 DOI: 10.1007/s00284-022-03103-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 10/28/2022] [Indexed: 12/04/2022]
Abstract
Mycoplasma pneumoniae, an obligate parasitic pathogen without cell wall, can cause severe upper and lower respiratory tract symptoms. It is the pathogen of human bronchitis and walking pneumonia, and named community-acquired pneumonia. In addition to severe respiratory symptoms, there are clinical extrapulmonary manifestations in the skin, brain, kidney, musculoskeletal, digestive system, and even blood system after M. pneumoniae infection. Hereby, we comprehensively summarized and reviewed the intrapulmonary and extrapulmonary pathogenesis of M. pneumoniae infection. The pathogenesis of related respiratory symptoms caused by M. pneumoniae is mainly adhesion damage, direct damage including nutrient predation, invasion and toxin, cytokine induced inflammation damage and immune evasion effect. The pathogenesis of extrapulmonary manifestations includes direct damage mediated by invasion and inflammatory factors, indirect damage caused by host immune response, and vascular occlusion. The intrapulmonary and extrapulmonary pathogenic mechanisms of M. pneumoniae infection are independent and interrelated, and have certain commonalities. In fact, the pathogenic mechanisms of M. pneumoniae are complicated, and the specific content is still not completely clear, further researches are necessary for determining the detailed pathogenesis of M. pneumoniae. This review can provide certain guidance for the effective prevention and treatment of M. pneumoniae infection.
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Wang T, Sun H, Lu Z, Jiang W, Dai G, Huang L, Wang M, Zhu C, Wang Y, Hao C, Yan Y, Chen Z. The CARDS toxin of Mycoplasma pneumoniae induces a positive feedback loop of type 1 immune response. Front Immunol 2022; 13:1054788. [PMID: 36532054 PMCID: PMC9752573 DOI: 10.3389/fimmu.2022.1054788] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 11/10/2022] [Indexed: 12/04/2022] Open
Abstract
Background Within the past 3-5 years, Mycoplasma pneumoniae has become a major pathogen of community-acquired pneumonia in children. The pathogenic mechanisms involved in M. pneumoniae infection have not been fully elucidated. Methods Previous protein microarray studies have shown a differential expression of CXCL9 after M. pneumoniae infection. Here, we conducted a hospital-based study to explore the clinical significance of the type 1 immune response inflammatory factors interferon (IFN)-γ and CXCL9 in patients with M. pneumoniae pneumonia (MPP). Then, through in vitro experiments, we explored whether CARDS toxin stimulated F-DCs (dendritic cells incubated with Flt3L) to promote Th-cell differentiation; we also investigated the IFN-γ-induced CXCL9 secretion pathway in macrophages and the role of CXCL9 in promoting Th1 cell migration. Results The CXCL9 expression level was upregulated among patients with a higher fever peak, fever duration of greater than 7 days, an imaging manifestation of lobar or segmental, or combined pleural effusion (P<0.05). The peripheral blood levels of IFN-γ and CXCL9, which were higher in patients than in the healthy control group, were positively correlated with each other (r=0.502, P<0.05). In patients, the CXCL9 expression level was significantly higher in the bronchoalveolar lavage fluid (BALF) than in the peripheral blood, and the BALF CXCL9 expression level was higher than that in the healthy control group (all P<0.05). Our flow cytometry analysis revealed that M1-phenotype macrophages (CD16 + CD64 + CD163-) were predominant in the BALF from children with MPP. In in vitro experiments, F-DCs stimulated with CARDS toxin promoted the differentiation of CD4 + IFN-γ + Th (Th1) cells (P<0.05). Moreover, IFN-γ induced high levels of CXCL9 expression in M1-type macrophages in a dose-dependent and time-dependent manner. Additionally, macrophages transfection with STAT1-siRNA-1 downregulated the expression of CXCL9 (P<0.05), and CXCL9 promoted Th1 cell migration (P<0.05). Conclusions Our findings suggest that CARDS toxin induces a type 1 immune response positive feedback loop during M. pneumoniae infection; this putative mechanism may be useful in future investigations of immune intervention approaches for M. pneumoniae pneumonia.
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Affiliation(s)
- Ting Wang
- Department of Respiratory Medicine, Children’s Hospital of Soochow University, Suzhou, China
| | - Huiming Sun
- Department of Respiratory Medicine, Children’s Hospital of Soochow University, Suzhou, China
| | - Zhitao Lu
- Department of Pediatrics, Zhangjiagang No.1 People’s Hospital, Affiliated Hospital of Soochow University, Suzhou, China
| | - Wujun Jiang
- Department of Respiratory Medicine, Children’s Hospital of Soochow University, Suzhou, China
| | - Ge Dai
- Department of Respiratory Medicine, Children’s Hospital of Soochow University, Suzhou, China
| | - Li Huang
- Department of Respiratory Medicine, Children’s Hospital of Soochow University, Suzhou, China
| | - Meijuan Wang
- Department of Respiratory Medicine, Children’s Hospital of Soochow University, Suzhou, China
| | - Canhong Zhu
- Department of Respiratory Medicine, Children’s Hospital of Soochow University, Suzhou, China
| | - Yuqing Wang
- Department of Respiratory Medicine, Children’s Hospital of Soochow University, Suzhou, China
| | - Chuangli Hao
- Department of Respiratory Medicine, Children’s Hospital of Soochow University, Suzhou, China
| | - Yongdong Yan
- Department of Respiratory Medicine, Children’s Hospital of Soochow University, Suzhou, China,*Correspondence: Zhengrong Chen, ; Yongdong Yan,
| | - Zhengrong Chen
- Department of Respiratory Medicine, Children’s Hospital of Soochow University, Suzhou, China,*Correspondence: Zhengrong Chen, ; Yongdong Yan,
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Acid-induced disassembly of the Haemophilus ducreyi cytolethal distending toxin. Biochem Biophys Res Commun 2022; 636:57-63. [DOI: 10.1016/j.bbrc.2022.10.068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 10/19/2022] [Indexed: 11/21/2022]
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Su X, You X, Luo H, Liang K, Chen L, Tian W, Ye Z, He J. Community-Acquired Respiratory Distress Syndrome Toxin: Unique Exotoxin for M. pneumoniae. Front Microbiol 2021; 12:766591. [PMID: 34867898 PMCID: PMC8640204 DOI: 10.3389/fmicb.2021.766591] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 10/19/2021] [Indexed: 11/13/2022] Open
Abstract
Mycoplasma pneumoniae infection often causes respiratory diseases in humans, particularly in children and adults with atypical pneumonia and community-acquired pneumonia (CAP), and is often exacerbated by co-infection with other lung diseases, such as asthma, bronchitis, and chronic obstructive pulmonary disorder. Community-acquired respiratory distress syndrome toxin (CARDS TX) is the only exotoxin produced by M. pneumoniae and has been extensively studied for its ADP-ribosyltransferase (ADPRT) activity and cellular vacuolization properties. Additionally, CARDS TX induces inflammatory responses, resulting in cell swelling, nuclear lysis, mucus proliferation, and cell vacuolization. CARDS TX enters host cells by binding to the host receptor and is then reverse transported to the endoplasmic reticulum to exert its pathogenic effects. In this review, we focus on the structural characteristics, functional activity, distribution and receptors, mechanism of cell entry, and inflammatory response of CARDS TX was examined. Overall, the findings of this review provide a theoretical basis for further investigation of the mechanism of M. pneumoniae infection and the development of clinical diagnosis and vaccines.
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Affiliation(s)
- Xiaoling Su
- The Affiliated Nanhua Hospital, Department of Clinical Laboratory, Hengyang Medical School, University of South China, Hengyang, China
| | - Xiaoxing You
- Institute of Pathogenic Biology, Hengyang Medical School, Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
| | - Haodang Luo
- The Affiliated Nanhua Hospital, Department of Clinical Laboratory, Hengyang Medical School, University of South China, Hengyang, China
| | - Keying Liang
- The Affiliated Nanhua Hospital, Department of Clinical Laboratory, Hengyang Medical School, University of South China, Hengyang, China
| | - Li Chen
- The Affiliated Nanhua Hospital, Department of Clinical Laboratory, Hengyang Medical School, University of South China, Hengyang, China
| | - Wei Tian
- The Affiliated Nanhua Hospital, Department of Clinical Laboratory, Hengyang Medical School, University of South China, Hengyang, China
| | - Zufeng Ye
- The Affiliated Nanhua Hospital, Department of Clinical Laboratory, Hengyang Medical School, University of South China, Hengyang, China
| | - Jun He
- The Affiliated Nanhua Hospital, Department of Clinical Laboratory, Hengyang Medical School, University of South China, Hengyang, China
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