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López-Collazo E, del Fresno C. Endotoxin tolerance and trained immunity: breaking down immunological memory barriers. Front Immunol 2024; 15:1393283. [PMID: 38742111 PMCID: PMC11089161 DOI: 10.3389/fimmu.2024.1393283] [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: 02/28/2024] [Accepted: 04/09/2024] [Indexed: 05/16/2024] Open
Abstract
For decades, innate immune cells were considered unsophisticated first responders, lacking the adaptive memory of their T and B cell counterparts. However, mounting evidence demonstrates the surprising complexity of innate immunity. Beyond quickly deploying specialized cells and initiating inflammation, two fascinating phenomena - endotoxin tolerance (ET) and trained immunity (TI) - have emerged. ET, characterized by reduced inflammatory response upon repeated exposure, protects against excessive inflammation. Conversely, TI leads to an enhanced response after initial priming, allowing the innate system to mount stronger defences against subsequent challenges. Although seemingly distinct, these phenomena may share underlying mechanisms and functional implications, blurring the lines between them. This review will delve into ET and TI, dissecting their similarities, differences, and the remaining questions that warrant further investigation.
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Affiliation(s)
- Eduardo López-Collazo
- The Innate Immune Response Group, Hospital la Paz Institute for Health Research (IdiPAZ), La Paz University Hospital, Madrid, Spain
- Tumour Immunology Laboratory, IdiPAZ, La Paz University Hospital, Madrid, Spain
- Centro de Investigación Biomédica en Red (CIBER), Respiratory Diseases (CIBRES), Madrid, Spain
| | - Carlos del Fresno
- The Innate Immune Response Group, Hospital la Paz Institute for Health Research (IdiPAZ), La Paz University Hospital, Madrid, Spain
- Immunomodulation Laboratory, IdiPAZ, La Paz University Hospital, Madrid, Spain
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Wan R, Srikaram P, Xie S, Chen Q, Hu C, Wan M, Li Y, Gao P. PPARγ attenuates cellular senescence of alveolar macrophages in asthma-COPD overlap. Respir Res 2024; 25:174. [PMID: 38643159 PMCID: PMC11032609 DOI: 10.1186/s12931-024-02790-6] [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: 03/03/2024] [Accepted: 03/25/2024] [Indexed: 04/22/2024] Open
Abstract
BACKGROUND Asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO) represents a complex condition characterized by shared clinical and pathophysiological features of asthma and COPD in older individuals. However, the pathophysiology of ACO remains unexplored. We aimed to identify the major inflammatory cells in ACO, examine senescence within these cells, and elucidate the genes responsible for regulating senescence. METHODS Bioinformatic analyses were performed to investigate major cell types and cellular senescence signatures in a public single-cell RNA sequencing (scRNA-Seq) dataset derived from the lung tissues of patients with ACO. Similar analyses were carried out in an independent cohort study Immune Mechanisms Severe Asthma (IMSA), which included bulk RNA-Seq and CyTOF data from bronchoalveolar lavage fluid (BALF) samples. RESULTS The analysis of the scRNA-Seq data revealed that monocytes/ macrophages were the predominant cell type in the lung tissues of ACO patients, constituting more than 50% of the cells analyzed. Lung monocytes/macrophages from patients with ACO exhibited a lower prevalence of senescence as defined by lower enrichment scores of SenMayo and expression levels of cellular senescence markers. Intriguingly, analysis of the IMSA dataset showed similar results in patients with severe asthma. They also exhibited a lower prevalence of senescence, particularly in airway CD206 + macrophages, along with increased cytokine expression (e.g., IL-4, IL-13, and IL-22). Further exploration identified alveolar macrophages as a major subtype of monocytes/macrophages driving cellular senescence in ACO. Differentially expressed genes related to oxidation-reduction, cytokines, and growth factors were implicated in regulating senescence in alveolar macrophages. PPARγ (Peroxisome Proliferator-Activated Receptor Gamma) emerged as one of the predominant regulators modulating the senescent signature of alveolar macrophages in ACO. CONCLUSION The findings suggest that senescence in macrophages, particularly alveolar macrophages, plays a crucial role in the pathophysiology of ACO. Furthermore, PPARγ may represent a potential therapeutic target for interventions aimed at modulating senescence-associated processes in ACO.Key words ACO, Asthma, COPD, Macrophages, Senescence, PPARγ.
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Affiliation(s)
- Rongjun Wan
- Division of Allergy and Clinical Immunology, Johns Hopkins University School of Medicine, Baltimore, MD, 21224, USA
- Department of Respiratory and Critical Care Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, 410008, China
| | - Prakhyath Srikaram
- Division of Allergy and Clinical Immunology, Johns Hopkins University School of Medicine, Baltimore, MD, 21224, USA
| | - Shaobing Xie
- Division of Allergy and Clinical Immunology, Johns Hopkins University School of Medicine, Baltimore, MD, 21224, USA
- Department of Otolaryngology Head and Neck Surgery, Xiangya Hospital of Central South University, Changsha, China
| | - Qiong Chen
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, 410008, China
- Department of Geriatrics, Xiangya Hospital, Central South University, Changsha, 410008, China
| | - Chengping Hu
- Department of Respiratory and Critical Care Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China
| | - Mei Wan
- Department of Orthopaedic Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Yuanyuan Li
- Department of Respiratory and Critical Care Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China.
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, 410008, China.
| | - Peisong Gao
- Division of Allergy and Clinical Immunology, Johns Hopkins University School of Medicine, Baltimore, MD, 21224, USA.
- The Johns Hopkins Asthma & Allergy Center, 5501 Hopkins Bayview Circle, Room 3B.71, Baltimore, MD, 21224, USA.
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Wan R, Srikaram P, Xie S, Chen Q, Hu C, Wan M, Li Y, Gao P. PPARγ Attenuates Cellular Senescence of Alveolar Macrophages in Asthma- COPD Overlap. RESEARCH SQUARE 2024:rs.3.rs-4009724. [PMID: 38496493 PMCID: PMC10942556 DOI: 10.21203/rs.3.rs-4009724/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
Asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO) represents a complex condition characterized by shared clinical and pathophysiological features of asthma and COPD in older individuals. However, the pathophysiology of ACO remains unexplored. We aimed to identify the major inflammatory cells in ACO, examine senescence within these cells, and elucidate the genes responsible for regulating senescence. Bioinformatic analyses were performed to investigate major cell types and cellular senescence signatures in a public single-cell RNA sequencing (scRNA-Seq) dataset derived from the lung tissues of patients with ACO. Similar analyses were carried out in an independent cohort study Immune Mechanisms Severe Asthma (IMSA), which included bulk RNA-Seq and CyTOF data from bronchoalveolar lavage fluid (BALF) samples. The analysis of the scRNA-Seq data revealed that monocytes/ macrophages were the predominant cell type in the lung tissues of ACO patients, constituting more than 50% of the cells analyzed. Lung monocytes/macrophages from patients with ACO exhibited a lower prevalence of senescence as defined by lower enrichment scores of SenMayo and expression levels of cellular senescence markers. Intriguingly, analysis of the IMSA dataset showed similar results in patients with severe asthma. They also exhibited a lower prevalence of senescence, particularly in airway CD206 + macrophages, along with increased cytokine expression (e.g., IL-4, IL-13, and IL-22). Further exploration identified alveolar macrophages as a major subtype of monocytes/macrophages driving cellular senescence in ACO. Differentially expressed genes related to oxidation-reduction, cytokines, and growth factors were implicated in regulating senescence in alveolar macrophages. PPARγ (Peroxisome Proliferator-Activated Receptor Gamma) emerged as one of the predominant regulators modulating the senescent signature of alveolar macrophages in ACO. Collectively, the findings suggest that senescence in macrophages, particularly alveolar macrophages, plays a crucial role in the pathophysiology of ACO. Furthermore, PPARγ may represent a potential therapeutic target for interventions aimed at modulating senescence-associated processes in ACO.
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Affiliation(s)
| | | | | | | | | | - Mei Wan
- Johns Hopkins University School of Medicine
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Cho SX, Rudloff I, Ellisdon AM, Nold-Petry CA, Nold MF. Thirteen years to get from b to a: one of the neglected isoforms of IL-37 enters the stage. Cell Mol Immunol 2024; 21:201-202. [PMID: 38105292 PMCID: PMC10805707 DOI: 10.1038/s41423-023-01111-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Accepted: 11/15/2023] [Indexed: 12/19/2023] Open
Affiliation(s)
- Steven X Cho
- Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia
- Department of Pediatrics, Monash University, Melbourne, VIC, Australia
| | - Ina Rudloff
- Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia
- Department of Pediatrics, Monash University, Melbourne, VIC, Australia
| | - Andrew M Ellisdon
- Cancer Program, Biomedicine Discovery Institute, Monash University, Melbourne, VIC, Australia
| | - Claudia A Nold-Petry
- Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia
- Department of Pediatrics, Monash University, Melbourne, VIC, Australia
| | - Marcel F Nold
- Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia.
- Department of Pediatrics, Monash University, Melbourne, VIC, Australia.
- Monash Newborn, Monash Children's Hospital, Melbourne, VIC, Australia.
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