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1.
Nat Commun ; 14(1): 3286, 2023 06 13.
Artículo en Inglés | MEDLINE | ID: mdl-37311745

RESUMEN

Some people remain healthier throughout life than others but the underlying reasons are poorly understood. Here we hypothesize this advantage is attributable in part to optimal immune resilience (IR), defined as the capacity to preserve and/or rapidly restore immune functions that promote disease resistance (immunocompetence) and control inflammation in infectious diseases as well as other causes of inflammatory stress. We gauge IR levels with two distinct peripheral blood metrics that quantify the balance between (i) CD8+ and CD4+ T-cell levels and (ii) gene expression signatures tracking longevity-associated immunocompetence and mortality-associated inflammation. Profiles of IR metrics in ~48,500 individuals collectively indicate that some persons resist degradation of IR both during aging and when challenged with varied inflammatory stressors. With this resistance, preservation of optimal IR tracked (i) a lower risk of HIV acquisition, AIDS development, symptomatic influenza infection, and recurrent skin cancer; (ii) survival during COVID-19 and sepsis; and (iii) longevity. IR degradation is potentially reversible by decreasing inflammatory stress. Overall, we show that optimal IR is a trait observed across the age spectrum, more common in females, and aligned with a specific immunocompetence-inflammation balance linked to favorable immunity-dependent health outcomes. IR metrics and mechanisms have utility both as biomarkers for measuring immune health and for improving health outcomes.


Asunto(s)
COVID-19 , Longevidad , Femenino , Humanos , Envejecimiento , Inflamación , Evaluación de Resultado en la Atención de Salud
2.
Front Immunol ; 13: 901273, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35844527

RESUMEN

Background: Malignancy is a major cause of morbidity and mortality in transplant recipients. Identification of those at highest risk could facilitate pre-emptive intervention such as reduction of immunosuppression. Reduced circulating monocytic HLA-DR density is a marker of immune depression in the general population and associates with poorer outcome in critical illness. It has recently been used as a safety marker in adoptive cell therapy trials in renal transplantation. Despite its potential as a marker of dampened immune responses, factors that impact upon monocytic HLA-DR density and the long-term clinical sequelae of this have not been assessed in transplant recipients. Methods: A cohort study of stable long-term renal transplant recipients was undertaken. Serial circulating monocytic HLA-DR density and other leucocyte populations were quantified by flow cytometry. Gene expression of monocytes was performed using the Nanostring nCounter platform, and 13-plex cytokine bead array used to quantify serum concentrations. The primary outcome was malignancy development during one-year follow-up. Risk of malignancy was calculated by univariate and multivariate proportionate hazards modelling with and without adjustment for competing risks. Results: Monocytic HLA-DR density was stable in long-term renal transplant recipients (n=135) and similar to non-immunosuppressed controls (n=29), though was suppressed in recipients receiving prednisolone. Decreased mHLA-DRd was associated with accumulation of CD14+CD11b+CD33+HLA-DRlo monocytic myeloid-derived suppressor-like cells. Pathway analysis revealed downregulation of pathways relating to cytokine and chemokine signalling in monocytes with low HLA-DR density; however serum concentrations of major cytokines did not differ between these groups. There was an independent increase in malignancy risk during follow-up with decreased HLA-DR density. Conclusions: Dampened chemokine and cytokine signalling drives a stable reduction in monocytic HLA-DR density in long-term transplant recipients and associates with subsequent malignancy risk. This may function as a novel marker of excess immunosuppression. Further study is needed to understand the mechanism behind this association.


Asunto(s)
Antígenos HLA-DR , Trasplante de Riñón , Monocitos , Células Supresoras de Origen Mieloide , Neoplasias , Estudios de Cohortes , Citocinas/inmunología , Antígenos HLA-DR/inmunología , Humanos , Monocitos/inmunología , Monocitos/patología , Células Supresoras de Origen Mieloide/inmunología , Células Supresoras de Origen Mieloide/patología , Neoplasias/sangre , Neoplasias/inmunología , Neoplasias/patología , Receptores de Trasplantes
3.
Am J Transplant ; 21(8): 2833-2845, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-33725408

RESUMEN

Personalizing immunosuppression is a major objective in transplantation. Transplant recipients are heterogeneous regarding their immunological memory and primary alloimmune susceptibility. This biomarker-guided trial investigated whether in low immunological-risk kidney transplants without pretransplant DSA and donor-specific T cells assessed by a standardized IFN-γ ELISPOT, low immunosuppression (LI) with tacrolimus monotherapy would be non-inferior regarding 6-month BPAR than tacrolimus-based standard of care (SOC). Due to low recruitment rates, the trial was terminated when 167 patients were enrolled. ELISPOT negatives (E-) were randomized to LI (n = 48) or SOC (n = 53), E+ received the same SOC. Six- and 12-month BPAR rates were higher among LI than SOC/E- (4/35 [13%] vs. 1/43 [2%], p = .15 and 12/48 [25%] vs. 6/53 [11.3%], p = .073, respectively). E+ patients showed similarly high BPAR rates than LI at 6 and 12 months (12/55 [22%] and 13/66 [20%], respectively). These differences were stronger in per-protocol analyses. Post-hoc analysis revealed that poor class-II eplet matching, especially DQ, discriminated E- patients, notably E-/LI, developing BPAR (4/28 [14%] low risk vs. 8/20 [40%] high risk, p = .043). Eplet mismatch also predicted anti-class-I (p = .05) and anti-DQ (p < .001) de novo DSA. Adverse events were similar, but E-/LI developed fewer viral infections, particularly polyoma-virus-associated nephropathy (p = .021). Preformed T cell alloreactivity and HLA eplet mismatch assessment may refine current baseline immune-risk stratification and guide immunosuppression decision-making in kidney transplantation.


Asunto(s)
Trasplante de Riñón , Tacrolimus , Rechazo de Injerto/etiología , Rechazo de Injerto/prevención & control , Supervivencia de Injerto , Prueba de Histocompatibilidad , Humanos , Terapia de Inmunosupresión , Inmunosupresores/uso terapéutico , Trasplante de Riñón/efectos adversos , Linfocitos T , Tacrolimus/uso terapéutico
4.
Am J Transplant ; 21(1): 21-31, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-32529725

RESUMEN

The International Workshop on Clinical Transplant Tolerance is a biennial meeting that aims to provide an update on the progress of studies of immunosuppression minimization or withdrawal in solid organ transplantation. The Fourth International Workshop on Clinical Tolerance was held in Pittsburgh, Pennsylvania, September 5-6, 2019. This report is a summary of presentations on the status of clinical trials designed to minimize or withdraw immunosuppressive drugs in kidney, liver, and lung transplantation without subsequent evidence of rejection. All protocols had in common the use of donor or recipient cell therapy combined with organ transplantation. The workshop also included presentations of mechanistic studies designed to improve understanding of the cellular and molecular basis of tolerance and to identify potential predictors/biomarkers of tolerance. Strategies to enhance the safety of hematopoietic cell transplantation and to improve patient selection/risk stratification for clinical trials were also discussed.


Asunto(s)
Trasplante de Órganos , Tolerancia al Trasplante , Rechazo de Injerto/etiología , Rechazo de Injerto/prevención & control , Humanos , Tolerancia Inmunológica , Terapia de Inmunosupresión , Inmunosupresores , Pennsylvania
5.
Am J Transplant ; 21(4): 1603-1611, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33171020

RESUMEN

Short-term outcomes in kidney transplantation are marred by progressive transplant failure and mortality secondary to immunosuppression toxicity. Immune modulation with autologous polyclonal regulatory T cell (Treg) therapy may facilitate immunosuppression reduction promoting better long-term clinical outcomes. In a Phase I clinical trial, 12 kidney transplant recipients received 1-10 × 106 Treg per kg at Day +5 posttransplantation in lieu of induction immunosuppression (Treg Therapy cohort). Nineteen patients received standard immunosuppression (Reference cohort). Primary outcomes were rejection-free and patient survival. Patient and transplant survival was 100%; acute rejection-free survival was 100% in the Treg Therapy versus 78.9% in the reference cohort at 48 months posttransplant. Treg therapy revealed no excess safety concerns. Four patients in the Treg Therapy cohort had mycophenolate mofetil withdrawn successfully and remain on tacrolimus monotherapy. Treg infusion resulted in a long-lasting dose-dependent increase in peripheral blood Tregs together with an increase in marginal zone B cell numbers. We identified a pretransplantation immune phenotype suggesting a high risk of unsuccessful ex-vivo Treg expansion. Autologous Treg therapy is feasible, safe, and is potentially associated with a lower rejection rate than standard immunosuppression. Treg therapy may provide an exciting opportunity to minimize immunosuppression therapy and improve long-term outcomes.


Asunto(s)
Trasplante de Riñón , Estudios de Factibilidad , Rechazo de Injerto/etiología , Rechazo de Injerto/prevención & control , Humanos , Inmunosupresores/uso terapéutico , Donadores Vivos , Monitorización Inmunológica , Linfocitos T Reguladores
6.
Sci Rep ; 10(1): 18397, 2020 10 27.
Artículo en Inglés | MEDLINE | ID: mdl-33110123

RESUMEN

The current state-of-the-art technology employed to assess anti-human leukocyte antigen antibodies (Anti-HLA Ab) for donor-recipient matching and patient risk stratification in renal transplantation is the single antigen bead (SAB) assay. However, there are limitations to the SAB assay as it is not quantitative and due to variations in techniques and reagents, there is no standardization across laboratories. In this study, a structurally-defined human monoclonal alloantibody was employed to provide a mechanistic explanation for how fundamental alloantibody biology influences the readout from the SAB assay. Performance of the clinical SAB assay was evaluated by altering Anti-HLA Ab concentration, subclass, and detection reagents. Tests were conducted in parallel by two internationally accredited laboratories using standardized protocols and reagents. We show that alloantibody concentration, subclass, laboratory-specific detection devices, subclass-specific detection reagents all contribute to a significant degree of variation in the readout. We report a significant prozone effect affecting HLA alleles that are bound strongly by the test alloantibody as opposed to those bound weakly and this phenomenon is independent of complement. These data highlight the importance for establishing international standards for SAB assay calibration and have significant implications for our understanding of discordance in previous studies that have analyzed its clinical relevance.


Asunto(s)
Antígenos HLA/inmunología , Algoritmos , Anticuerpos Monoclonales/inmunología , Antígenos HLA/química , Humanos , Estructura Molecular
7.
Commun Biol ; 3(1): 375, 2020 07 14.
Artículo en Inglés | MEDLINE | ID: mdl-32665635

RESUMEN

Regulatory T cells (Tregs) are critical mediators of immune homeostasis. The co-stimulatory molecule CD27 is a marker of highly suppressive Tregs, although the role of the CD27-CD70 receptor-ligand interaction in Tregs is not clear. Here we show that after prolonged in vitro stimulation, a significant proportion of human Tregs gain stable CD70 expression while losing CD27. The expression of CD70 in expanded Tregs is associated with a profound loss of regulatory function and an unusual ability to provide CD70-directed co-stimulation to TCR-activated conventional T cells. Genetic deletion of CD70 or its blockade prevents Tregs from delivering this co-stimulatory signal, thus maintaining their regulatory activity. High resolution targeted single-cell RNA sequencing of human peripheral blood confirms the presence of CD27-CD70+ Treg cells. These findings have important implications for Treg-based clinical studies where cells are expanded over extended periods in order to achieve sufficient treatment doses.


Asunto(s)
Ligando CD27/metabolismo , Linfocitos T Reguladores/inmunología , Animales , Ligando CD27/genética , Proteína 9 Asociada a CRISPR , Sistemas CRISPR-Cas , Femenino , Citometría de Flujo , Factores de Transcripción Forkhead/metabolismo , Edición Génica , Técnicas de Inactivación de Genes , Humanos , Ratones Endogámicos BALB C , Análisis de Secuencia de ARN , Linfocitos T Reguladores/metabolismo , Linfocitos T Reguladores/trasplante , Transcriptoma , Miembro 7 de la Superfamilia de Receptores de Factores de Necrosis Tumoral/metabolismo
8.
Front Immunol ; 10: 889, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31068951

RESUMEN

Regulatory T cells (Tregs) can control excessive or undesirable immune responses toward autoantigens, alloantigens, and pathogens. In transplantation, host immune responses against the allograft are suppressed through the use of immunosuppressive drugs, however this often results in life-threatening side effects including nephrotoxicity and an increased incidence of cancer and opportunistic infections. Tregs can control graft-vs.-host disease and transplant rejection in experimental models, providing impetus for the use of Tregs as a cellular therapy in clinical transplantation. One of the major barriers to the widespread use of Treg cellular therapy is the requirement to expand cells ex vivo to large numbers in order to alter the overall balance between regulatory and effector cells. Methods that enhance suppressive capacity thereby reducing the need for expansion are therefore of interest. Here, we have compared the function of freshly-isolated and ex vivo-manipulated human Tregs in a pre-clinical humanized mouse model of skin transplantation. Sorted human CD127loCD25+CD4+ Tregs were assessed in three different conditions: freshly-isolated, following transient in vitro activation with antiCD3/antiCD28 beads or after ex vivo-expansion for 2 weeks in the presence of antiCD3/antiCD28 beads and recombinant human IL2. While ex vivo-expansion of human Tregs increased their suppressive function moderately, transient in vitro-activation of freshly isolated Tregs resulted in a powerful enhancement of Treg activity sufficient to promote long-term graft survival of all transplants in vivo. In order to investigate the mechanisms responsible for these effects, we measured the expression of Treg-associated markers and susceptibility to apoptosis in activated Tregs. Transiently activated Tregs displayed enhanced survival and proliferation in vitro and in vivo. On a molecular level, Treg activation resulted in an increased expression of anti-apoptotic BCL2L1 (encoding BCL-XL) which may be at least partially responsible for the observed enhancement in function. Our results suggest that in vitro activation of human Tregs arms them with superior proliferative and survival abilities, enabling them to more effectively control alloresponses. Importantly, this transient activation results in a rapid functional enhancement of freshly-isolated Tregs, thereby providing an opportunity to eliminate the need for in vitro expansion in select circumstances. A protocol employing this technique would therefore benefit from a reduced requirement for large cell numbers for effective therapy.


Asunto(s)
Regulación de la Expresión Génica , Activación de Linfocitos/genética , Activación de Linfocitos/inmunología , Linfocitos T Reguladores/inmunología , Linfocitos T Reguladores/metabolismo , Proteína bcl-X/genética , Animales , Apoptosis/genética , Apoptosis/inmunología , Biomarcadores , Supervivencia Celular/genética , Supervivencia Celular/inmunología , Humanos , Tolerancia Inmunológica , Inmunomodulación , Inmunofenotipificación , Ratones , Ratones Noqueados , Trasplante de Piel , Proteína bcl-X/metabolismo
9.
Nat Commun ; 10(1): 893, 2019 02 21.
Artículo en Inglés | MEDLINE | ID: mdl-30792391

RESUMEN

Our understanding of the conformational and electrostatic determinants that underlie targeting of human leukocyte antigens (HLA) by anti-HLA alloantibodies is principally based upon in silico modelling. Here we provide a biochemical/biophysical and functional characterization of a human monoclonal alloantibody specific for a common HLA type, HLA-A*11:01. We present a 2.4 Å resolution map of the binding interface of this antibody on HLA-A*11:01 and compare the structural determinants with those utilized by T-cell receptor (TCR), killer-cell immunoglobulin-like receptor (KIR) and CD8 on the same molecule. These data provide a mechanistic insight into the paratope-epitope relationship between an alloantibody and its target HLA molecule in a biological context where other immune receptors are concomitantly engaged. This has important implications for our interpretation of serologic binding patterns of anti-HLA antibodies in sensitized individuals and thus, for the biology of human alloresponses.


Asunto(s)
Antígeno HLA-A11/química , Antígeno HLA-A11/metabolismo , Isoanticuerpos/química , Isoanticuerpos/metabolismo , Secuencia de Aminoácidos , Anticuerpos Monoclonales/química , Anticuerpos Monoclonales/genética , Anticuerpos Monoclonales/metabolismo , Especificidad de Anticuerpos , Complejo Antígeno-Anticuerpo/química , Complejo Antígeno-Anticuerpo/genética , Complejo Antígeno-Anticuerpo/metabolismo , Sitios de Unión de Anticuerpos/genética , Cristalografía por Rayos X , Epítopos/química , Epítopos/genética , Epítopos/metabolismo , Antígeno HLA-A11/genética , Humanos , Inmunoglobulina G/química , Inmunoglobulina G/genética , Inmunoglobulina G/metabolismo , Isoanticuerpos/genética , Modelos Moleculares , Biblioteca de Péptidos , Conformación Proteica
10.
Methods Mol Biol ; 1899: 43-54, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30649764

RESUMEN

Regulatory T cells (Tregs) are a population of lymphocytes that exerts suppressive effects upon the immune system. In human peripheral blood, the major population of T lymphocytes with suppressive capacity are defined by expression of the T cell co-receptor CD4 and the interleukin-2 receptor α-chain (CD25), combined with minimal expression of the interleukin-7 receptor α subunit (CD127). We begin by outlining the method for isolating peripheral blood mononuclear cells (PBMCs) from human blood by centrifugation of whole blood overlayed on a hydrophilic polysaccharide, with an additional erythrocyte lysis step. The protocol that follows utilizes Fluorescence-Activated Cell Sorting (FACS) for the isolation of this CD4+CD25+CD127lo population of regulatory T cells, with high yield and purity, from immunostained PBMCs. Prior to FACS isolation, this protocol exploits magnetic immunoselection for pre-enrichment of CD25+ PBMC, which reduces the duration of the subsequent FACS isolation.


Asunto(s)
Separación Celular/métodos , Citometría de Flujo/métodos , Linfocitos T Reguladores/citología , Antígenos CD4/genética , Humanos , Subunidad alfa del Receptor de Interleucina-2/genética , Subunidad alfa del Receptor de Interleucina-7/genética , Leucocitos Mononucleares/citología , Recuento de Linfocitos , Linfocitos T Reguladores/inmunología
11.
Methods Mol Biol ; 1899: 159-180, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30649772

RESUMEN

In this chapter, we describe the history of transplantation, the multiple cell types, and mechanisms that are involved in rejection and tolerance of a transplanted organ, as well as summarize the common and promising new therapeutics used in transplant patients.


Asunto(s)
Rechazo de Injerto/inmunología , Tolerancia Inmunológica , Trasplante de Órganos/métodos , Tolerancia al Trasplante/inmunología , Humanos , Terapia de Inmunosupresión
12.
Front Immunol ; 9: 1184, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29904381

RESUMEN

Background: T follicular helper (Tfh) cells are key players in the production of antibody-producing B cells via the germinal center reaction. Therapeutic strategies targeting Tfh cells are important where antibody formation is implicated in disease, such as transplant rejection and autoimmune diseases. We investigated the impact of the immunosuppressive agent tacrolimus on human Tfh cell differentiation and function in transplant recipients. Methods: Paired blood and lymph node (LN) samples were obtained from 61 transplant recipients immediately prior to organ implantation. Living-donor recipients received a week of tacrolimus prior to kidney transplantation. Deceased-donor recipients served as controls, as tacrolimus was not administered until after the transplant operation. Flow cytometry was used to compare LN and circulating cell subsets. Results: The calcineurin inhibitor (CNIs) tacrolimus specifically suppresses both LN Tfh cells and circulating Tfh cells, but not their regulatory counterparts or other CD4 T cell subsets. Conclusion: Our findings suggest that CNIs may have a more important role in the prevention of antibody formation than previously understood and, therefore, have potential for antibody-associated conditions in which aberrant Tfh function has been implicated in disease.


Asunto(s)
Rechazo de Injerto/inmunología , Trasplante de Riñón , Linfocitos T Reguladores/inmunología , Adulto , Anciano , Formación de Anticuerpos , Linfocitos B , Inhibidores de la Calcineurina , Diferenciación Celular , Citocinas/metabolismo , Femenino , Centro Germinal , Humanos , Inmunosupresores , Activación de Linfocitos , Masculino , Persona de Mediana Edad , Linfocitos T Colaboradores-Inductores , Tacrolimus , Receptores de Trasplantes
13.
JCI Insight ; 2(19)2017 10 05.
Artículo en Inglés | MEDLINE | ID: mdl-28978798

RESUMEN

T cells are central to the detrimental alloresponses that develop in autoimmunity and transplantation, with CD28 costimulatory signals being key to T cell activation and proliferation. CTLA4-Ig molecules that bind CD80/86 and inhibit CD28 costimulation offer an alternative immunosuppressive treatment, free from some of the chronic toxicities associated with calcineurin inhibition. However, CD80/86 blockade by CTLA4-Ig also results in the loss of coinhibitory CTLA4 signals that are critical to the regulation of T cell activation. Here, we show that a nonactivating monovalent anti-CD28 that spares CTLA4 signaling is an effective immunosuppressant in a clinically relevant humanized mouse transplant model. We demonstrate that selective CD28 blockade prolongs human skin allograft survival through a mechanism that includes a reduction in the cellular graft infiltrate. Critically, selective CD28 blockade promotes Treg function in vivo and synergizes with adoptive Treg therapy to promote transplant survival. In contrast to CTLA4-Ig treatment, selective CD28 blockade promotes regulation of alloimmune responses and facilitates Treg-based cellular therapy.


Asunto(s)
Antígenos CD28/inmunología , Subgrupos de Linfocitos T/inmunología , Animales , Autoinmunidad , Antígeno CTLA-4/inmunología , Citocinas/sangre , Supervivencia de Injerto/inmunología , Xenoinjertos , Humanos , Mediadores de Inflamación/metabolismo , Activación de Linfocitos/inmunología , Ratones Endogámicos BALB C , Trasplante de Piel , Linfocitos T Reguladores/inmunología , Inmunología del Trasplante
14.
Immunol Lett ; 190: 139-147, 2017 10.
Artículo en Inglés | MEDLINE | ID: mdl-28823885

RESUMEN

Adoptive cellular therapies are gaining popularity as a means to treat clinical conditions, with potentially fewer risks and greater efficacy than traditional pharmacological strategies. Regulatory T cells (Tregs) are currently undergoing clinical trials in various immune-mediated pathologies, including transplant rejection and autoimmune conditions. In general, cell therapy relies upon ex vivo expansion of the cell product, in order to administer more cells than can be isolated from one person. In vitro manipulation of cell therapy products, prior to administration to patients, offers the opportunity to enhance the efficacy of the final cell therapy product in other ways. For example, cells can be exposed to reagents that enhance their longevity or functional potency after transfer into the patient. Genetic modification strategies can even permit the design of cells with bespoke functionality. Crucially, in vitro manipulation of therapeutic cells in isolation can exert these influences upon the biology of the therapeutic cells, without systemic exposure of the patient to the reagents being used. Quality control assessments can be integrated into the procedure prior to administration, to protect the patient from the risk of adverse events, should the procedure produce undesirable results. With a particular focus on Tregs, this review surveys the diverse strategies that are being employed to enhance the efficacy of cell therapy via in vitro manipulation of cells, and highlights some emerging technologies that may propel this endeavour in the future.


Asunto(s)
Enfermedades Autoinmunes/inmunología , Rechazo de Injerto/inmunología , Inmunoterapia Adoptiva/métodos , Técnicas de Cultivo de Célula , Humanos , Linfocitos T Reguladores/inmunología , Linfocitos T Reguladores/trasplante
15.
N Engl J Med ; 377(5): 442-453, 2017 08 03.
Artículo en Inglés | MEDLINE | ID: mdl-28767349

RESUMEN

BACKGROUND: Donor-specific antibodies create an immunologic barrier to transplantation. Current therapies to modify donor-specific antibodies are limited and ineffective in the most highly HLA-sensitized patients. The IgG-degrading enzyme derived from Streptococcus pyogenes (IdeS), an endopeptidase, cleaves human IgG into F(ab')2 and Fc fragments inhibiting complement-dependent cytotoxicity and antibody-dependent cellular cytotoxicity, which suggests that IdeS might be useful for desensitization. We report on the combined experience of two independently performed open-label, phase 1-2 trials (conducted in Sweden and the United States) that assessed the efficacy of IdeS with regard to desensitization and transplantation of a kidney from an HLA-incompatible donor. METHODS: We administered IdeS to 25 highly HLA-sensitized patients (11 patients in Uppsala or Stockholm, Sweden, and 14 in Los Angeles) before the transplantation of a kidney from an HLA-incompatible donor. Frequent monitoring for adverse events, outcomes, donor-specific antibodies, and renal function was performed, as were renal biopsies. Immunosuppression after transplantation consisted of tacrolimus, mycophenolate mofetil, and glucocorticoids. Patients in the U.S. study also received intravenous immune globulin and rituximab after transplantation to prevent antibody rebound. RESULTS: Recipients in the U.S. study had a significantly longer cold ischemia time (the time elapsed between procurement of the organ and transplantation), a significantly higher rate of delayed graft function, and significantly higher levels of class I donor-specific antibodies than those in the Swedish study. A total of 38 serious adverse events occurred in 15 patients (5 events were adjudicated as being possibly related to IdeS). At transplantation, total IgG and HLA antibodies were eliminated. A total of 24 of 25 patients had perfusion of allografts after transplantation. Antibody-mediated rejection occurred in 10 patients (7 patients in the U.S. study and 3 in the Swedish study) at 2 weeks to 5 months after transplantation; all these patients had a response to treatment. One graft loss, mediated by non-HLA IgM and IgA antibodies, occurred. CONCLUSIONS: IdeS reduced or eliminated donor-specific antibodies and permitted HLA-incompatible transplantation in 24 of 25 patients. (Funded by Hansa Medical; ClinicalTrials.gov numbers, NCT02224820 , NCT02426684 , and NCT02475551 .).


Asunto(s)
Proteínas Bacterianas/uso terapéutico , Cisteína Endopeptidasas/uso terapéutico , Antígenos HLA/inmunología , Terapia de Inmunosupresión/métodos , Trasplante de Riñón , Inmunología del Trasplante , Adulto , Anticuerpos/sangre , Proteínas Bacterianas/efectos adversos , Complemento C1q/inmunología , Cisteína Endopeptidasas/efectos adversos , Femenino , Prueba de Histocompatibilidad , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina G/metabolismo , Masculino , Persona de Mediana Edad
17.
J Vis Exp ; (122)2017 04 19.
Artículo en Inglés | MEDLINE | ID: mdl-28448002

RESUMEN

The measurement of immunological reactivity to donor antigens in transplant recipients is likely to be crucial for the successful reduction or withdrawal of immunosuppression. The mixed leukocyte reaction (MLR), limiting dilution assays, and trans-vivo delayed-type hypersensitivity (DTH) assay have all been applied to this question, but these methods have limited predictive ability and/or significant practical limitations that reduce their usefulness. Imaging flow cytometry is a technique that combines the multiparametric quantitative powers of flow cytometry with the imaging capabilities of fluorescent microscopy. We recently made use of an imaging flow cytometry approach to define the proportion of recipient T cells capable of forming mature immune synapses with donor antigen-presenting cells (APCs). Using a well-characterized mouse heart transplant model, we have shown that the frequency of in vitro immune synapses among T-APC membrane contact events strongly predicted allograft outcome in rejection, tolerance, and a situation where transplant survival depends on induced regulatory T cells. The frequency of T-APC contacts increased with T cells from mice during acute rejection and decreased with T cells from mice rendered unresponsive to alloantigen. The addition of regulatory T cells to the in vitro system reduced prolonged T-APC contacts. Critically, this effect was also seen with human polyclonally expanded, naturally occurring regulatory T cells, which are known to control the rejection of human tissues in humanized mouse models. Further development of this approach may allow for a deeper characterization of the alloreactive T-cell compartment in transplant recipients. In the future, further development and evaluation of this method using human cells may form the basis for assays used to select patients for immunosuppression minimization, and it can be used to measure the impact of tolerogenic therapies in the clinic.


Asunto(s)
Citometría de Flujo/métodos , Isoantígenos/inmunología , Linfocitos T/inmunología , Animales , Antígenos/inmunología , Linfocitos T CD4-Positivos/inmunología , Células Dendríticas/inmunología , Supervivencia de Injerto/inmunología , Trasplante de Corazón/métodos , Tolerancia Inmunológica , Terapia de Inmunosupresión/métodos , Ratones Endogámicos CBA , Linfocitos T Reguladores/inmunología , Trasplante Homólogo
18.
Transplant Direct ; 3(1): e125, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28349125

RESUMEN

BACKGROUND: Renal transplant recipients (RTR) frequently develop complications relating to chronic immunosuppression. Identifying RTR who could safely reduce immunosuppression is therefore highly desirable. We hypothesized that "signatures" described in RTR who have stopped immunosuppression but maintained stable graft function ("operational tolerance") may enable identification of immunosuppressed RTR who are candidates for immunosuppression minimization. However, the effect of immunosuppression itself on these signatures and circulating B-cell populations is currently unknown. METHODS: We undertook a cross-sectional study of 117 RTR to assess the effect of immunosuppression upon circulating B cell populations, humoral alloresponse and 2 previously published "signatures" of operational tolerance. RESULTS: Immunosuppression associated with alterations in both published "signatures." Azathioprine associated with a decrease in transitional and naive B-cell numbers and calcineurin inhibition associated with an increase in the number of circulating plasmablasts. However, only azathioprine use associated with the presence of donor-specific anti-HLA IgG antibodies. Calcineurin inhibition associated with an increase in total serum IgM but not IgG. Data were corrected for age, time since last transplant, and other immunosuppression. CONCLUSIONS: Current signatures of operational tolerance may be significantly affected by immunosuppressive regimen, which may hinder use in their current form in clinical practice. Calcineurin inhibition may prevent the development of long-lasting humoral alloresponses, whereas azathioprine therapy may be associated with donor specific antibody development.

19.
Transplantation ; 101(2): 302-309, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-28118317

RESUMEN

BACKGROUND: Adoptive transfer of forkhead box protein (FOX)3 regulatory T (Treg) cells offers a promising strategy to reduce damage to an allograft by the recipient's immune system. Identification of cell surface markers sufficient to purify Treg cells expanded ex vivo to remove cellular contaminants requires optimization. Furthermore, the expanded Treg must be able to survive, expand, and suppress in allograft recipients exposed to immunosuppressants, such as tacrolimus (TAC). Reduced CD127 expression enhances identification of Treg in the human CD4CD25 population. CD45RA expression identifies naive CD4CD25 Treg with an enhanced stability of Treg phenotype. METHODS: We combine an analysis of CD45RA, CD25, and CD127 expression to identify subpopulations of CD4CD127CD25 cells. Regulatory T cells were sorted according to expression of CD25 and CD45RA and expanded in the presence of a physiological relevant concentration of TAC. Regulatory T cell-specific demethylation region (TSDR) demethylation, FOXP3 expression, and suppression were analyzed. RESULTS: CD4CD127CD25CD45RA Treg cells had a stable TSDR demethylated FOXP3 phenotype after expansion whereas CD4CD127CD25CD45RA Treg cell lost the TSDR demethylated phenotype. CD45RA Treg had a greater capacity to suppress after expansion with TAC. CONCLUSIONS: Although CD45RA Treg retained a greater suppressive capacity when expanded with TAC, the marked loss of the TSDR demethylated status highlights the potential for loss of stability of these cells in transplant recipients treated with TAC based immunosuppression. We show that a population of CD4CD127CD45RA Regulatory T cell may offer the best compromise between susceptibility to loss of suppression when exposed to TAC and maintenance of a TSDR demethylated phenotype following in vitro expansion.


Asunto(s)
Inhibidores de la Calcineurina/farmacología , Metilación de ADN , Inmunosupresores/farmacología , Subunidad alfa del Receptor de Interleucina-2/inmunología , Subunidad alfa del Receptor de Interleucina-7/inmunología , Antígenos Comunes de Leucocito/inmunología , Linfocitos T Reguladores/efectos de los fármacos , Tacrolimus/farmacología , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Citocinas/inmunología , Citocinas/metabolismo , Citometría de Flujo , Factores de Transcripción Forkhead/inmunología , Factores de Transcripción Forkhead/metabolismo , Humanos , Inmunofenotipificación/métodos , Subunidad alfa del Receptor de Interleucina-2/metabolismo , Subunidad alfa del Receptor de Interleucina-7/metabolismo , Antígenos Comunes de Leucocito/metabolismo , Activación de Linfocitos/efectos de los fármacos , Fenotipo , Linfocitos T Reguladores/inmunología , Linfocitos T Reguladores/metabolismo
20.
Transplantation ; 101(12): 2825-2829, 2017 12.
Artículo en Inglés | MEDLINE | ID: mdl-28072758

RESUMEN

Recent progress in deciphering the mechanisms underlying the concepts of tumor immunosurveillance and immunoevasion has opened new opportunities for the development of effective antitumor therapies. Transplant physicians and immunologists have much to learn from those direct clinical translations of basic science. The 2016 Beaune Seminar in Transplant research brought together researchers from both fields to explore and discuss significant advances in cancer biology, immunotherapies and their potential impacts for the management of cancer in transplant recipients.


Asunto(s)
Sistema Inmunológico , Neoplasias/inmunología , Neoplasias/cirugía , Trasplante/métodos , Alergia e Inmunología , Antineoplásicos/uso terapéutico , Congresos como Asunto , Humanos , Inmunosupresores/uso terapéutico , Inmunoterapia , Oncología Médica
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