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The Presence of a Marked Imbalance Between Regulatory T Cells and Effector T Cells Reveals That Tolerance Mechanisms Could Be Compromised in Heart Transplant Children. Transplant Direct 2021; 7:e693. [PMID: 33928185 PMCID: PMC8078462 DOI: 10.1097/txd.0000000000001152] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 03/05/2021] [Accepted: 03/06/2021] [Indexed: 12/19/2022] Open
Abstract
Regulatory T cells (Treg) are crucial for the induction and maintenance of graft tolerance. In pediatric heart transplant procedures, the thymus is routinely excised, removing the primary source of T-cell replenishment. Consequently, thymectomy joined to the effects of immunosuppression on the T-cell compartment may have a detrimental impact on Treg values, compromising the intrinsic tolerance mechanisms and the protective role of Treg preventing graft rejection in heart transplant children.
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López-Abente J, Martínez-Bonet M, Bernaldo-de-Quirós E, Camino M, Gil N, Panadero E, Gil-Jaurena JM, Clemente M, Urschel S, West L, Pion M, Correa-Rocha R. Basiliximab impairs regulatory T cell (TREG) function and could affect the short-term graft acceptance in children with heart transplantation. Sci Rep 2021; 11:827. [PMID: 33436905 PMCID: PMC7803770 DOI: 10.1038/s41598-020-80567-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 12/21/2020] [Indexed: 12/26/2022] Open
Abstract
CD25, the alpha chain of the IL-2 receptor, is expressed on activated effector T cells that mediate immune graft damage. Induction immunosuppression is commonly used in solid organ transplantation and can include antibodies blocking CD25. However, regulatory T cells (Tregs) also rely on CD25 for their proliferation, survival, and regulatory function. Therefore, CD25-blockade may compromise Treg protective role against rejection. We analysed in vitro the effect of basiliximab (BXM) on the viability, phenotype, proliferation and cytokine production of Treg cells. We also evaluated in vivo the effect of BXM on Treg in thymectomized heart transplant children receiving BXM in comparison to patients not receiving induction therapy. Our results show that BXM reduces Treg counts and function in vitro by affecting their proliferation, Foxp3 expression, and IL-10 secretion capacity. In pediatric heart-transplant patients, we observed decreased Treg counts and a diminished Treg/Teff ratio in BXM-treated patients up to 6-month after treatment, recovering baseline values at the end of the 12-month follow up period. These results reveal that the use of BXM could produce detrimental effects on Tregs, and support the evidence suggesting that BXM induction could impair the protective role of Tregs in the period of highest incidence of acute graft rejection.
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Affiliation(s)
- Jacobo López-Abente
- Laboratory of Immune-Regulation, Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Pabellón de Medicina Experimental, Planta Baja. C/ Maiquez, 6., 28006, Madrid, Spain
| | - Marta Martínez-Bonet
- Laboratory of Immune-Regulation, Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Pabellón de Medicina Experimental, Planta Baja. C/ Maiquez, 6., 28006, Madrid, Spain
| | - Esther Bernaldo-de-Quirós
- Laboratory of Immune-Regulation, Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Pabellón de Medicina Experimental, Planta Baja. C/ Maiquez, 6., 28006, Madrid, Spain
| | - Manuela Camino
- Pediatric-Cardiology Department, Hospital General Universitario Gregorio Marañón, Madrid, Spain
| | - Nuria Gil
- Pediatric-Cardiology Department, Hospital General Universitario Gregorio Marañón, Madrid, Spain
| | - Esther Panadero
- Pediatric-Cardiology Department, Hospital General Universitario Gregorio Marañón, Madrid, Spain
| | - Juan Miguel Gil-Jaurena
- Pediatric Cardiac Surgery Unit, Hospital General Universitario Gregorio Marañón, Madrid, Spain
| | - Maribel Clemente
- Cell Culture Unit, Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Madrid, Spain
| | - Simon Urschel
- Pediatric Cardiac Transplantation, University of Alberta/Stollery Children's Hospital, Edmonton, AB, Canada.,Alberta Transplant Institute, University of Alberta, Edmonton, AB, Canada.,Canadian National Transplant Research Program Investigator, CNTRP, Edmonton, AB, Canada
| | - Lori West
- Pediatric Cardiac Transplantation, University of Alberta/Stollery Children's Hospital, Edmonton, AB, Canada.,Alberta Transplant Institute, University of Alberta, Edmonton, AB, Canada.,Canadian National Transplant Research Program Investigator, CNTRP, Edmonton, AB, Canada
| | - Marjorie Pion
- Laboratory of Immune-Regulation, Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Pabellón de Medicina Experimental, Planta Baja. C/ Maiquez, 6., 28006, Madrid, Spain
| | - Rafael Correa-Rocha
- Laboratory of Immune-Regulation, Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Pabellón de Medicina Experimental, Planta Baja. C/ Maiquez, 6., 28006, Madrid, Spain. .,Canadian National Transplant Research Program Investigator, CNTRP, Edmonton, AB, Canada.
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Abstract
PURPOSE OF REVIEW To summarize the promises and limitations of candidate noninvasive immunological biomarkers in cardiac rejection, with a special focus on the chemokine CXCL10, as a pretransplant predictive marker of early heart acute rejection. Potential issues for transfer from research to the clinic are addressed. RECENT FINDINGS Early changes of immune biomolecules in peripheral blood, reflecting graft or heart recipient's immune status, are candidate biomarkers able to diagnose or predict cardiac rejection, ideally giving an opportunity to intervene before heart failure occurs. The support of robust analytical methodologies is necessary for the transition from biomarker discovery to clinical implementation. SUMMARY Cardiac rejection represents the main problem after heart transplantation. Endomyocardial biopsy, although invasive and not risk free, is the gold-standard procedure for rejection monitoring. Noninvasive heart damage biomarkers manifest substantially after rejection occurrence. The goal is to detect graft injury at the earliest possible stage in disease initiation. Some biomolecules associated with the early immune response to cardiac allograft retain the power to be diagnostic and, even better, predictive of acute rejection, as in the case of pretransplant CXCL10 serum level. Multicenter studies for assay validation and standardization, integrated analysis of multiple biomarkers, and cost-effectiveness evaluation are mandatory efforts.
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Frank R, Dean SA, Molina MR, Kamoun M, Lal P. Correlations of lymphocyte subset infiltrates with donor-specific antibodies and acute antibody-mediated rejection in endomyocardial biopsies. Cardiovasc Pathol 2014; 24:168-72. [PMID: 25440957 DOI: 10.1016/j.carpath.2014.11.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Revised: 10/31/2014] [Accepted: 11/03/2014] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND Acute antibody-mediated rejection (AMR) is a major complication after heart transplantation, posing a significant risk for allograft failure, cardiac allograft vasculopathy, and poor survival. While the inflammatory milieu of cellular rejection and Quilty lesions is well known, the immunologic components of AMR are not well understood. Our aim was to better define the immunophenotype of infiltrating lymphocytes in biopsies with AMR, specifically in relation to donor-specific antibodies to human leukocyte antigen (HLA) class I, II, or both. METHOD We performed a retrospective analysis of cardiac transplant patients with concurrent endomyocardial biopsies (EMB), donor-specific antibody (DSA) measurements, and immunofluorescence for C4d at our institution (2005-2011). DSA was evaluated against HLA class I and class II specificities pre- and posttransplant using flow cytometry and/or Luminex bead assays. Acute cellular rejection (ACR) and pathologic AMR (pAMR) were based on the International Society for Heart and Lung Transplantation 2005/2013 reports. Immunohistochemical analysis for CD3, CD4, CD8, and CD79a was performed using standard immunohistochemical protocols on one formalin-fixed, paraffin-embedded EMB from each patient. The number of lymphocytes expressing each protein was enumerated microscopically at 400×. Ratios of T:B cells and CD4:CD8 T cells were then calculated for each EMB. RESULTS Seventy-nine cardiac transplant patients who had pre- and posttransplant DSA measurements were analyzed. Of these 79 patients, 37 had DSA against HLA class I, HLA class II, or both. Of patients with DSA, the average CD4:CD8 ratio in the EMB was 0.80, while those with only ACR had a CD4:CD8 ratio of 1.49. Interestingly, the T:B cell ratio in patients with and without DSA was 5.7 and 5.5, respectively. CONCLUSION Cardiac transplant patients with DSA against HLA have more CD8 cytotoxic T cells than CD4 helper T cells in the EMB lymphocytic infiltrate compared with patients without DSA against HLA. The inflammatory infiltrate T:B cell ratio was similar in patients both with and without DSA. The relative increase of cytotoxic T cells in EMB while the patient has DSA suggests a possible pathogenic role of these cells and may aid in the diagnosis and treatment of AMR.
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Affiliation(s)
- Renee Frank
- Pathology and Laboratory Medicine, Hospital of the University of Pennsylvania, Philadelphia, PA, United States.
| | - Stephanie A Dean
- Pathology and Laboratory Medicine, Hospital of the University of Pennsylvania, Philadelphia, PA, United States
| | - Maria R Molina
- Heart Failure and Cardiac Transplant Program, Division of Cardiovascular Medicine, Hospital of the University of Pennsylvania, Philadelphia, PA, United States
| | - Malek Kamoun
- Pathology and Laboratory Medicine, Hospital of the University of Pennsylvania, Philadelphia, PA, United States
| | - Priti Lal
- Pathology and Laboratory Medicine, Hospital of the University of Pennsylvania, Philadelphia, PA, United States
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Abstract
Flow cytometry is increasingly recognized as an invaluable technology in biomarker research. Owing to its multiparametric nature it can provide highly detailed information on any single cell in a heterogeneous population. Its versatility means it can be conducted in both the preclinical and clinical setting, generating biomarker data that can drive decisions pertaining to dose selection in clinical trials, treatment options for cancer sufferers and even suitability of patients to receive transplants. Most tissue types can be utilized by the flow cytometrist, allowing the technology to be applied to many fields of research, yet consensus still needs to be reached on standardization, regulation and validation of multiparametric flow cytometry assays. In parallel, continual innovation in analysis software to manage the huge datasets that can be generated is also needed. Nevertheless, the flexibility of flow cytometry means that it remains at the forefront of both routine and exploratory biomarker studies.
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