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Khan MA, Lau CL, Krupnick AS. Monitoring regulatory T cells as a prognostic marker in lung transplantation. Front Immunol 2023; 14:1235889. [PMID: 37818354 PMCID: PMC10561299 DOI: 10.3389/fimmu.2023.1235889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 09/11/2023] [Indexed: 10/12/2023] Open
Abstract
Lung transplantation is the major surgical procedure, which restores normal lung functioning and provides years of life for patients suffering from major lung diseases. Lung transplant recipients are at high risk of primary graft dysfunction, and chronic lung allograft dysfunction (CLAD) in the form of bronchiolitis obliterative syndrome (BOS). Regulatory T cell (Treg) suppresses effector cells and clinical studies have demonstrated that Treg levels are altered in transplanted lung during BOS progression as compared to normal lung. Here, we discuss levels of Tregs/FOXP3 gene expression as a crucial prognostic biomarker of lung functions during CLAD progression in clinical lung transplant recipients. The review will also discuss Treg mediated immune tolerance, tissue repair, and therapeutic strategies for achieving in-vivo Treg expansion, which will be a potential therapeutic option to reduce inflammation-mediated graft injuries, taper the toxic side effects of ongoing immunosuppressants, and improve lung transplant survival rates.
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Kazmi S, Khan MA, Shamma T, Altuhami A, Assiri AM, Broering DC. Therapeutic nexus of T cell immunometabolism in improving transplantation immunotherapy. Int Immunopharmacol 2022; 106:108621. [DOI: 10.1016/j.intimp.2022.108621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 02/03/2022] [Accepted: 02/10/2022] [Indexed: 11/26/2022]
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Khan MA, Shamma T, Altuhami A, Ahmed HA, Assiri AM, Broering DC. CTLA4-Ig mediated immunosuppression favors immunotolerance and restores graft in mouse airway transplants. Pharmacol Res 2022; 178:106147. [DOI: 10.1016/j.phrs.2022.106147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 02/21/2022] [Accepted: 02/24/2022] [Indexed: 11/25/2022]
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Targeting Interleukin-10 Restores Graft Microvascular Supply and Airway Epithelium in Rejecting Allografts. Int J Mol Sci 2022; 23:ijms23031269. [PMID: 35163192 PMCID: PMC8836023 DOI: 10.3390/ijms23031269] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 01/09/2022] [Accepted: 01/12/2022] [Indexed: 12/12/2022] Open
Abstract
Interleukin-10 (IL-10) is a vital regulatory cytokine, which plays a constructive role in maintaining immune tolerance during an alloimmune inflammation. Our previous study highlighted that IL-10 mediated immunosuppression established the immune tolerance phase and thereby modulated both microvascular and epithelial integrity, which affected inflammation-associated graft malfunctioning and sub-epithelial fibrosis in rejecting allografts. Here, we further investigated the reparative effects of IL-10 on microvasculature and epithelium in a mouse model of airway transplantation. To investigate the IL-10 mediated microvascular and epithelial repair, we depleted and reconstituted IL-10, and monitored graft microvasculature, airway epithelium, and associated repair proteins. Our data demonstrated that both untreated control allografts and IL-10 (−) allografts showed a significant early (d6) increase in microvascular leakiness, drop-in tissue oxygenation, blood perfusion, and denuded airway epithelium, which is associated with loss of adhesion protein Fascin-1 and β-catenin on vascular endothelial cells at d10 post-transplantation. However, IL-10 (+) promotes early microvascular and airway epithelial repair, and a proportional increase in endothelial Fascin-1, and β-catenin at d10 post-transplantation. Moreover, airway epithelial cells also express a significantly higher expression of FOXJ1 and β-catenin in syngrafts and IL-10 (+) allografts as compared to IL-10 (−) and untreated controls at d10 post-transplantation. Collectively, these findings demonstrated that IL-10 mediated microvascular and epithelial changes are associated with the expression of FOXJ1, β-catenin, and Fascin-1 proteins on the airway epithelial and vascular endothelial cells, respectively. These findings establish a potential reparative modulation of IL-10 associated microvascular and epithelial repair, which could provide a vital therapeutic strategy to facilitate graft repair in clinical settings.
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Khan MA, Ashoor GA, Shamma T, Alanazi F, Altuhami A, Kazmi S, Ahmed HA, Mohammed Assiri A, Clemens Broering D. IL-10 Mediated Immunomodulation Limits Subepithelial Fibrosis and Repairs Airway Epithelium in Rejecting Airway Allografts. Cells 2021; 10:1248. [PMID: 34069395 PMCID: PMC8158696 DOI: 10.3390/cells10051248] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 04/01/2021] [Accepted: 04/20/2021] [Indexed: 12/11/2022] Open
Abstract
Interleukin-10 plays a vital role in maintaining peripheral immunotolerance and favors a regulatory immune milieu through the suppression of T effector cells. Inflammation-induced microvascular loss has been associated with airway epithelial injury, which is a key pathological source of graft malfunctioning and subepithelial fibrosis in rejecting allografts. The regulatory immune phase maneuvers alloimmune inflammation through various regulatory modulators, and thereby promotes graft microvascular repair and suppresses the progression of fibrosis after transplantation. The present study was designed to investigate the therapeutic impact of IL-10 on immunotolerance, in particular, the reparative microenvironment, which negates airway epithelial injury, and fibrosis in a mouse model of airway graft rejection. Here, we depleted and reconstituted IL-10, and serially monitored the phase of immunotolerance, graft microvasculature, inflammatory cytokines, airway epithelium, and subepithelial collagen in rejecting airway transplants. We demonstrated that the IL-10 depletion suppresses FOXP3+ Tregs, tumor necrosis factor-inducible gene 6 protein (TSG-6), graft microvasculature, and establishes a pro-inflammatory phase, which augments airway epithelial injury and subepithelial collagen deposition while the IL-10 reconstitution facilitates FOXP3+ Tregs, TSG-6 deposition, graft microvasculature, and thereby favors airway epithelial repair and subepithelial collagen suppression. These findings establish a potential reparative modulation of IL-10-associated immunotolerance on microvascular, epithelial, and fibrotic remodeling, which could provide a vital therapeutic option to rescue rejecting transplants in clinical settings.
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Affiliation(s)
- Mohammad Afzal Khan
- Organ Transplant Centre of Excellence, King Faisal Specialist Hospital and Research Centre, Riyadh 12713, Saudi Arabia; (T.S.); (F.A.); (A.A.); (S.K.); (D.C.B.)
| | | | - Talal Shamma
- Organ Transplant Centre of Excellence, King Faisal Specialist Hospital and Research Centre, Riyadh 12713, Saudi Arabia; (T.S.); (F.A.); (A.A.); (S.K.); (D.C.B.)
| | - Fatimah Alanazi
- Organ Transplant Centre of Excellence, King Faisal Specialist Hospital and Research Centre, Riyadh 12713, Saudi Arabia; (T.S.); (F.A.); (A.A.); (S.K.); (D.C.B.)
| | - Abdullah Altuhami
- Organ Transplant Centre of Excellence, King Faisal Specialist Hospital and Research Centre, Riyadh 12713, Saudi Arabia; (T.S.); (F.A.); (A.A.); (S.K.); (D.C.B.)
| | - Shadab Kazmi
- Organ Transplant Centre of Excellence, King Faisal Specialist Hospital and Research Centre, Riyadh 12713, Saudi Arabia; (T.S.); (F.A.); (A.A.); (S.K.); (D.C.B.)
| | - Hala Abdalrahman Ahmed
- Comparative Medicine Department, King Faisal Specialist Hospital and Research Centre, Riyadh 12713, Saudi Arabia; (H.A.A.); (A.M.A.)
| | - Abdullah Mohammed Assiri
- Comparative Medicine Department, King Faisal Specialist Hospital and Research Centre, Riyadh 12713, Saudi Arabia; (H.A.A.); (A.M.A.)
- College of Medicine, Alfaisal University, Riyadh 11533, Saudi Arabia
| | - Dieter Clemens Broering
- Organ Transplant Centre of Excellence, King Faisal Specialist Hospital and Research Centre, Riyadh 12713, Saudi Arabia; (T.S.); (F.A.); (A.A.); (S.K.); (D.C.B.)
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Heim C, Kuckhahn A, Ramsperger-Gleixner M, Nicolls MR, Weyand M, Ensminger SM. Microvasculature in murine tracheal allografts after combined therapy with clopidogrel and everolimus. Interact Cardiovasc Thorac Surg 2021; 32:960-968. [PMID: 33550369 DOI: 10.1093/icvts/ivab021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 01/01/2021] [Indexed: 11/12/2022] Open
Abstract
OBJECTIVES Survival after lung transplantation is mainly limited by the development of chronic lung allograft dysfunction. Previous studies have suggested T-cell mediated proliferation and microvascular changes in experimental small airways models as potential therapeutic targets. The aim of this study was to assess microvascular changes in murine orthotopic tracheal allografts after treatment with everolimus alone or in combination with clopidogrel. METHODS C57Bl/6 (H-2b) donor tracheas were orthotopically transplanted into CBA (H-2k) recipients. Mice received daily injections of everolimus (0.05 mg/kg) alone or combined with clopidogrel (1 mg/kg). Twenty-eight days after transplantation, ratio of the thickness of tracheal epithelium and lamina propria was measured as an indicator for chronic rejection. Additionally, graft oxygenation and graft perfusion were detected on postoperative days 4, 10 and 28. Quantitative reverse transcription polymerase chain reaction analysis was used for gene expression analysis. RESULTS While syngeneic grafts showed a stable tissue pO2 and undisturbed microvascular perfusion, rejecting allografts had a drastic decline in both parameters as well as a flattened epithelium and an increased thickness of the lamina propria. Treatment with everolimus reduced allogeneic fibroproliferation, but had no protective effects on the microvasculature; polymerase chain reaction analysis indicated hypoxic stress and inflammation. Combining everolimus with clopidogrel improved microvascular integrity in the tracheal grafts, but had no synergistic effect in preventing obliterative bronchiolitis development. CONCLUSIONS These data demonstrate that the ability of everolimus to reduce the development of post-transplant obliterative bronchiolitis is not caused by microvascular protection and has no synergistic effects with clopidogrel in acute airway rejection.
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Affiliation(s)
- Christian Heim
- Department of Cardiac Surgery, University of Erlangen-Nuremberg, Erlangen, Germany
| | - Annika Kuckhahn
- Department of Cardiac Surgery, University of Erlangen-Nuremberg, Erlangen, Germany
| | | | - Mark R Nicolls
- Veterans Affairs Palo Alto Health Care System/Stanford University School of Medicine, Stanford, CA, USA
| | - Michael Weyand
- Department of Cardiac Surgery, University of Erlangen-Nuremberg, Erlangen, Germany
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Khan MA. Regulatory T cells mediated immunomodulation during asthma: a therapeutic standpoint. J Transl Med 2020; 18:456. [PMID: 33267824 PMCID: PMC7713035 DOI: 10.1186/s12967-020-02632-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 08/26/2020] [Indexed: 12/24/2022] Open
Abstract
Asthma is an inflammatory disease of the lung airway network, which is initiated and perpetuated by allergen-specific CD4+ T cells, IgE antibodies, and a massive release of Th2 cytokines. The most common clinical manifestations of asthma progression include airway inflammation, pathological airway tissue and microvascular remodeling, which leads to airway hyperresponsiveness (AHR), and reversible airway obstruction. In addition to inflammatory cells, a tiny population of Regulatory T cells (Tregs) control immune homeostasis, suppress allergic responses, and participate in the resolution of inflammation-associated tissue injuries. Preclinical and clinical studies have demonstrated a tremendous therapeutic potential of Tregs in allergic airway disease, which plays a crucial role in immunosuppression, and rejuvenation of inflamed airways. These findings supported to harness the immunotherapeutic potential of Tregs to suppress airway inflammation and airway microvascular reestablishment during the progression of the asthma disease. This review addresses the therapeutic impact of Tregs and how Treg mediated immunomodulation plays a vital role in subduing the development of airway inflammation, and associated airway remodeling during the onset of disease.
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Affiliation(s)
- Mohammad Afzal Khan
- Organ Transplant Research Section, Comparative Medicine Department, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia.
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Khan MA, Shamma T, Kazmi S, Altuhami A, Ahmed HA, Assiri AM, Broering DC. Hypoxia-induced complement dysregulation is associated with microvascular impairments in mouse tracheal transplants. J Transl Med 2020; 18:147. [PMID: 32234039 PMCID: PMC7110829 DOI: 10.1186/s12967-020-02305-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Accepted: 03/16/2020] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Complement Regulatory Proteins (CRPs), especially CD55 primarily negate complement factor 3-mediated injuries and maintain tissue homeostasis during complement cascade activation. Complement activation and regulation during alloimmune inflammation contribute to allograft injury and therefore we proposed to investigate a crucial pathological link between vascular expression of CD55, active-C3, T cell immunity and associated microvascular tissue injuries during allograft rejection. METHODS Balb/c→C57BL/6 allografts were examined for microvascular deposition of CD55, C3d, T cells, and associated tissue microvascular impairments during rejection in mouse orthotopic tracheal transplantation. RESULTS Our findings demonstrated that hypoxia-induced early activation of HIF-1α favors a cell-mediated inflammation (CD4+, CD8+, and associated proinflammatory cytokines, IL-2 and TNF-α), which proportionally triggers the downregulation of CRP-CD55, and thereby augments the uncontrolled release of active-C3, and Caspase-3 deposition on CD31+ graft vascular endothelial cells. These molecular changes are pathologically associated with microvascular deterioration (low tissue O2 and Blood flow) and subsequent airway epithelial injuries of rejecting allografts as compared to non-rejecting syngrafts. CONCLUSION Together, these findings establish a pathological correlation between complement dysregulation, T cell immunity, and microvascular associated injuries during alloimmune inflammation in transplantation.
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Affiliation(s)
- Mohammad Afzal Khan
- Organ Transplant Research Section, Comparative Medicine Department, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia.
| | - Talal Shamma
- Organ Transplant Research Section, Comparative Medicine Department, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia
| | - Shadab Kazmi
- Organ Transplant Research Section, Comparative Medicine Department, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia
| | - Abdullah Altuhami
- Organ Transplant Research Section, Comparative Medicine Department, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia
| | - Hala Abdalrahman Ahmed
- Comparative Medicine Department, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia
| | - Abdullah Mohammed Assiri
- Comparative Medicine Department, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia.,College of Medicine, Alfaisal University, Riyadh, Kingdom of Saudi Arabia.,Institute for Research and Medical Consultations, Imam Abdulrahman Bin Faisal University, Dammam, Kingdom of Saudi Arabia
| | - Dieter Clemens Broering
- Organ Transplant Research Section, Comparative Medicine Department, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia
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Platelets: Mechanistic and Diagnostic Significance in Transplantation. CURRENT TRANSPLANTATION REPORTS 2020. [DOI: 10.1007/s40472-020-00272-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Abstract
Purpose of Review
In addition to their function in coagulation, platelets recently have been recognized as an important component of innate immune responses. This review relates salient immune functions of platelets to transplants.
Recent Findings
Platelets are critical bridges between vascular endothelium and leukocytes. Real-time imaging of platelets has demonstrated that platelets rapidly adhere to vascular endothelium and form a nidus for attachment of neutrophils and then monocytes. However, the majority of platelets subsequently release from endothelium and return to the circulation in an activated state. These recycled platelets have the potential to transport proteins and RNA from the graft to the recipient. Some of the platelets that return to the circulation are attached to leukocytes.
Summary
Platelets have the potential to modulate many elements of the graft and the immune response from the time of organ retrieval through ischemia-reperfusion to acute and chronic rejection. Beyond mechanistic considerations, assays that detect changes in platelet protein or RNA expression could be used to monitor early inflammatory responses in transplants.
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