RESUMO
Rheumatoid arthritis (RA) patients present higher risk of SARS-CoV-2 infection (COVID-19), and proper management of the disease in this population requires a better understanding of how the immune system controls the virus. We analyzed the T cell and B cell phenotypes, and their repertoire in a pair of monozygotic twins with RA mismatched for COVID-19 infection. Twin- was not infected, while Twin+ was infected and effectively controlled the infection. We found no significant changes on the αß T cell composition, while γδ T cells and B cells presented considerable expansion of memory population in Twin+ and robust T/B cell responses to several SARS-CoV-2 peptides. T cell receptor ß/γ-chain and immunoglobulin heavy chain next-generation sequencing depicted a remarkable higher diversity in Twin+ compared with Twin-, despite no significant changes being found in variable/joining family usage. Repertoire overlap analyses showed that, although being identical twins, very few clones were shared between them, indicating that COVID-19 may lead to deep changes on the immune cell repertoire in RA patients. Altogether, our results indicate that RA patients may develop robust and persistent COVID-19-specific T/B cell responses; γδ T cells and B cells may play a key role in the management of COVID-19 in RA, and the infection may lead to a profound reshaping of immune cell receptor specificities.
Assuntos
Artrite Reumatoide , COVID-19 , Doenças em Gêmeos/genética , Humanos , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Receptores de Antígenos de Linfócitos T gama-delta , SARS-CoV-2 , Linfócitos T , Gêmeos Monozigóticos/genéticaRESUMO
Less than a third of patients with acute myeloid leukemia (AML) are cured by chemotherapy and/or hematopoietic stem cell transplantation, highlighting the need to develop more efficient drugs. The low efficacy of standard treatments is associated with inadequate depletion of CD34+ blasts and leukemic stem cells, the latter a drug-resistant subpopulation of leukemia cells characterized by the CD34+CD38- phenotype. To target these drug-resistant primitive leukemic cells better, we have designed a CD34/CD3 bi-specific T-cell engager (BTE) and characterized its anti-leukemia potential in vitro, ex vivo and in vivo. Our results show that this CD34-specific BTE induces CD34-dependent T-cell activation and subsequent leukemia cell killing in a dose-dependent manner, further corroborated by enhanced T-cell-mediated killing at the singlecell level. Additionally, the BTE triggered efficient T-cell-mediated depletion of CD34+ hematopoietic stem cells from peripheral blood stem cell grafts and CD34+ blasts from AML patients. Using a humanized AML xenograft model, we confirmed that the CD34-specific BTE had in vivo efficacy by depleting CD34+ blasts and leukemic stem cells without side effects. Taken together, these data demonstrate that the CD34-specific BTE has robust antitumor effects, supporting development of a novel treatment modality with the aim of improving outcomes of patients with AML and myelodysplastic syndromes.
Assuntos
Leucemia Mieloide Aguda , Células-Tronco Neoplásicas , Antígenos CD34 , Moléculas de Adesão Celular , Humanos , Imunofenotipagem , Leucemia Mieloide Aguda/patologia , Leucemia Mieloide Aguda/terapia , Células-Tronco Neoplásicas/patologia , Linfócitos T/patologiaRESUMO
OBJECTIVES: The rationale of autologous haematopoietic stem cell transplantation (AHSCT) for autoimmune diseases is that high-dose immunosuppression eradicates autoreactive T and B cells and the infused autologous haematopoietic stem cells promote reconstitution of a naïve and self-tolerant immune system. The aim of this study was to evaluate the reconstitution of different B cell subsets, both quantitatively and functionally, in SSc patients treated with AHSCT. METHODS: Peripheral blood was harvested from 22 SSc patients before transplantation and at 30, 60, 120, 180 and 360 days post-AHSCT. Immunophenotyping of B cell subsets, B cell cytokine production, signalling pathways and suppressive capacity of regulatory B cells (Bregs) were assessed by flow cytometry. RESULTS: Naïve B cell frequencies increased from 60 to 360 days post-AHSCT compared with pre-transplantation. Conversely, memory B cell frequencies decreased during the same period. Plasma cell frequencies transiently decreased at 60 days post-AHSCT. IL-10-producing Bregs CD19+CD24hiCD38hi and CD19+CD24hiCD27+ frequencies increased at 180 days. Moreover, the phosphorylation of extracellular signal-regulated kinase 1/2 and p38 mitogen-activated protein kinase increased in B cells reconstituted post-AHSCT. Notably, CD19+CD24hiCD38hi Bregs recovered their ability to suppress production of Th1 cytokines by CD4+ T cells at 360 days post-AHSCT. Finally, IL-6 and TGF-ß1-producing B cells decreased following AHSCT. CONCLUSION: Taken together, these results suggest improvements in immunoregulatory and anti-fibrotic mechanisms after AHSCT for SSc, which may contribute to re-establishment of self-tolerance and clinical remission.
Assuntos
Linfócitos B Reguladores/imunologia , Transplante de Células-Tronco Hematopoéticas/métodos , Células B de Memória/imunologia , Escleroderma Sistêmico/terapia , Adolescente , Adulto , Linfócitos B Reguladores/patologia , Células Cultivadas , Citocinas/metabolismo , Feminino , Citometria de Fluxo , Seguimentos , Humanos , Imunofenotipagem , Contagem de Linfócitos , Masculino , Células B de Memória/patologia , Pessoa de Meia-Idade , Estudos Retrospectivos , Escleroderma Sistêmico/imunologia , Escleroderma Sistêmico/patologia , Fatores de Tempo , Transplante Autólogo , Resultado do Tratamento , Adulto JovemRESUMO
Although the impact of donor graft composition on clinical outcomes after hematopoietic stem cell transplantation (HSCT) has been studied, little is known about the role of intragraft γδ TCR repertoire on clinical outcomes following HSCT. Using a high-throughput sequencing platform, we sought to analyze the TCR γ-chain (TRG) repertoire of γδ T cells within donor stem cell grafts and address its potential impact on clinical response in the corresponding patients. A total of 20 peripheral blood stem cell grafts were analyzed, and donors were classified as CMV+/- The respective acute myeloid leukemia recipients were followed for disease relapse and acute graft-versus-host disease (aGvHD) development post-HSCT. In all samples, TRG repertoire showed a reduced diversity and displayed overrepresented clones. This was more prominent in grafts from CMV+ donors, which presented a more private repertoire, lower diversity, skewed distribution, and reduced usage of the V9-JP pairing. Grafts given to nonrelapse patients presented a more public repertoire and increased presence of long sequence clonotypes. Variable-joining gene segment usage was not associated with aGvHD development, but a higher usage of V2-JP1 pairing and lower usage of V4-J2/V5-J2/V8-JP2 were observed in grafts given to nonrelapse patients. Our work identified five private overrepresented and one public CDR3 sequence (CATWDGPYYKKLF) associated with CMV infection, in addition to 12 highly frequent public sequences present exclusively in grafts given to nonrelapse patients. Our findings show that, despite CMV infection reshaping the TRG repertoire, TRG composition is not associated with aGvHD development, and several public sequences are associated with clinical remission.
Assuntos
Infecções por Citomegalovirus/imunologia , Transplante de Células-Tronco Hematopoéticas , Leucemia Mieloide Aguda/terapia , Receptores de Antígenos de Linfócitos T gama-delta/imunologia , Transplantes/virologia , Resultado do Tratamento , Adulto , Idoso , Células Clonais , Feminino , Doença Enxerto-Hospedeiro/epidemiologia , Doença Enxerto-Hospedeiro/imunologia , Doença Enxerto-Hospedeiro/virologia , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/virologia , Adulto JovemRESUMO
High dose immunosuppression followed by autologous hematopoietic stem cell transplantation (AHSCT) induces prolonged clinical remission in multiple sclerosis (MS) patients. However, how patient immune profiles are associated with clinical outcomes has not yet been completely elucidated. In this study, 37 MS patients were assessed for neurological outcomes, thymic function and long-term immune reconstitution after AHSCT. Patients were followed for a mean (SD) of 68.5 (13.9) months post-transplantation and were retrospectively clustered into progression- and non-progression groups, based on Expanded Disease Status Scale (EDSS) outcomes at last visit. After AHSCT, both patient groups presented increased regulatory T-cell subset counts, early expansion of central- and effector-memory CD8(+)T-cells and late thymic reactivation. However, the non-progression group presented early expansion of PD-1(+)CD8(+)T-cells and of PD-1-expressing CD19(+) B-cells. Here, we suggest that along with increased numbers of regulatory T-cell subsets, PD-1 inhibitory signaling is one possible immunoregulatory mechanism by which AHSCT restores immune tolerance in MS patients.
Assuntos
Transplante de Células-Tronco Hematopoéticas/métodos , Esclerose Múltipla Recidivante-Remitente/terapia , Linfócitos T/imunologia , Timo/imunologia , Adulto , Antígenos CD19/imunologia , Antígenos CD19/metabolismo , Linfócitos B/imunologia , Linfócitos B/metabolismo , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Progressão da Doença , Feminino , Humanos , Contagem de Linfócitos , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla Recidivante-Remitente/imunologia , Avaliação de Resultados em Cuidados de Saúde , Receptor de Morte Celular Programada 1/imunologia , Receptor de Morte Celular Programada 1/metabolismo , Estudos Retrospectivos , Transdução de Sinais/imunologia , Linfócitos T/metabolismo , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/metabolismo , Fatores de Tempo , Transplante Autólogo , Adulto JovemAssuntos
Variação Antigênica , Células Clonais/imunologia , Citomegalovirus/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Escleroderma Sistêmico/virologia , Adulto , Células Clonais/virologia , Feminino , Transplante de Células-Tronco Hematopoéticas , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Recidiva , Escleroderma Sistêmico/imunologia , Escleroderma Sistêmico/terapia , Transplante Autólogo , Adulto JovemRESUMO
Despite the considerable progress in acute myeloid leukemia (AML) treatment, relapse after allogeneic hematopoietic stem cell transplantation (HSCT) is still frequent and associated with a poor prognosis. Relapse has been shown to be correlated with an incomplete eradication of CD34+ leukemic stem cells prior to HSCT. Previously, we have shown that a novel CD34-directed, bispecific T-cell engager (BTE) can efficiently redirect the T-cell effector function toward cancer cells, thus eliminating leukemic cells in vitro and in vivo. However, its impact on γδ T-cells is still unclear. In this study, we tested the efficacy of the CD34-specific BTE using in vitro expanded γδ T-cells as effectors. We showed that the BTEs bind to γδ T-cells and CD34+ leukemic cell lines and induce target cell killing in a dose-dependent manner. Additionally, γδ T-cell mediated killing was found to be superior to αß T-cell mediated cytotoxicity. Furthermore, we observed that only in the presence of BTE the γδ T-cells induced primary AML blast killing in vitro. Importantly, our results show that γδ T-cells did not target the healthy CD34intermediate endothelial blood-brain barrier cell line (hCMEC/D3) nor lysed CD34+ HSCs from healthy bone marrow samples.
Assuntos
Anticorpos Biespecíficos , Antígenos CD34 , Complexo CD3 , Leucemia Mieloide Aguda , Receptores de Antígenos de Linfócitos T gama-delta , Humanos , Anticorpos Biespecíficos/farmacologia , Anticorpos Biespecíficos/uso terapêutico , Leucemia Mieloide Aguda/imunologia , Leucemia Mieloide Aguda/terapia , Leucemia Mieloide Aguda/patologia , Leucemia Mieloide Aguda/metabolismo , Antígenos CD34/metabolismo , Complexo CD3/imunologia , Receptores de Antígenos de Linfócitos T gama-delta/metabolismo , Receptores de Antígenos de Linfócitos T gama-delta/imunologia , Ativação Linfocitária/imunologia , Linhagem Celular Tumoral , Citotoxicidade Imunológica , Linfócitos T/imunologia , Linfócitos T/metabolismo , Linfócitos Intraepiteliais/imunologia , Linfócitos Intraepiteliais/metabolismoRESUMO
Allogeneic Hematopoietic stem cell transplantation (allo-HCT) is a curative platform for several hematological diseases. Despite its therapeutic benefits, the profound immunodeficiency associated with the transplant procedure remains a major challenge that renders patients vulnerable to several complications. Today, It is well established that a rapid and efficient immune reconstitution, particularly of the T cell compartment is pivotal to both a short-term and a long-term favorable outcome. T cells expressing a TCR heterodimer comprised of gamma (γ) and delta (δ) chains have received particular attention in allo-HCT setting, as a large body of evidence has indicated that γδ T cells can exert favorable potent anti-tumor effects without inducing severe graft versus host disease (GVHD). However, despite their potential role in allo-HCT, studies investigating their detailed reconstitution in patients after allo-HCT are scarce. In this review we aim to shed lights on the current literature and understanding of γδ T cell reconstitution kinetics as well as the different transplant-related factors that may influence γδ reconstitution in allo-HCT. Furthermore, we will present data from available reports supporting a role of γδ cells and their subsets in patient outcome. Finally, we discuss the current and future strategies to develop γδ cell-based therapies to exploit the full immunotherapeutic potential of γδ cells in HCT setting.
Assuntos
Doença Enxerto-Hospedeiro , Transplante de Células-Tronco Hematopoéticas , Reconstituição Imune , Linfócitos Intraepiteliais , Neoplasias , Transplante de Células-Tronco Hematopoéticas/métodos , Humanos , Linfócitos Intraepiteliais/patologiaRESUMO
As the thymus represents the primary site of T-cell development, optimal thymic function is of paramount importance for the successful reconstitution of the adaptive immunity after allogeneic hematopoietic stem cell transplantation. Thymus involutes as part of the aging process and several factors, including previous chemotherapy treatments, conditioning regimen used in preparation to the allograft, occurrence of graft-versus-host disease, and steroid therapy that impair the integrity of the thymus, thus affecting its role in supporting T-cell neogenesis. Although the pathways governing its regeneration are still poorly understood, the thymus has a remarkable capacity to recover its function after damage. Measurement of both recent thymic emigrants and T-cell receptor excision circles is valuable tools to assess thymic output and gain insights on its function. In this review, we will extensively discuss available data on factors regulating thymic function after allogeneic hematopoietic stem cell transplantation, as well as the strategies and therapeutic approaches under investigation to promote thymic reconstitution and accelerate immune recovery in transplanted patients, including the use of cytokines, sex-steroid ablation, precursor T-cells, and thymus bioengineering. Although none of them is routinely used in the clinic, these approaches have the potential to enhance thymic function and immune recovery, not only in patients given an allograft but also in other conditions characterized by immune deficiencies related to a defective function of the thymus.
Assuntos
Doença Enxerto-Hospedeiro , Transplante de Células-Tronco Hematopoéticas , Transplante de Medula Óssea , Doença Enxerto-Hospedeiro/etiologia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Humanos , Linfócitos T , Transplante HomólogoRESUMO
The role of γδ T cells in antitumor immunity has been under investigation for the past two decades, but little is known about their contribution to clinical outcomes in patients. Here, we set out to define the clonotypic, phenotypic, and functional features of γδ T cells in peripheral blood, ascites, and metastatic tumor tissue from patients with advanced epithelial ovarian cancer. T cell receptor (TCR) sequencing of the γ chain revealed that tumor-infiltrating γδ T cells have a unique and skewed repertoire with high TCR diversity and low clonality. In contrast, ascites-derived γδ T cells presented a lower TCR diversity and higher clonality, suggesting a TCR-dependent clonal focusing at this site. Further investigation showed that tumor samples had abundant γδ T cells with a tissue-resident, activation-associated phenotype, less usage of Vγ9 and an impaired response to adaptive-associated stimuli, implying an innate-like activation pathway, rather than an adaptive TCR-engaging pathway, at these tumor sites. Furthermore, high γδ T cell cytokine responsiveness upon stimulation was associated with a favorable outcome for patients in terms of both overall survival and reduced residual tumor burden after primary surgery. Last, the functionality of γδ T cells and patient survival were negatively affected by the proportions of CD39-expressing T cells, highlighting the potential of CD39 as a target to improve γδ T cell responses and unleash their antitumor capabilities.
Assuntos
Neoplasias Ovarianas , Receptores de Antígenos de Linfócitos T gama-delta , Ascite , Carcinoma Epitelial do Ovário , Feminino , Humanos , Linfócitos TRESUMO
Hematopoietic stem cell transplantation (HSCT) is an effective treatment option for several malignant and non-malignant hematological diseases. The clinical outcome of this procedure relies to a large extent on optimal recovery of adaptive immunity. In this regard, the thymus plays a central role as the primary site for de novo generation of functional, diverse, and immunocompetent T-lymphocytes. The thymus is exquisitely sensitive to several insults during HSCT, including conditioning drugs, corticosteroids, infections, and graft-vs.-host disease. Impaired thymic recovery has been clearly associated with increased risk of opportunistic infections and poor clinical outcomes in HSCT recipients. Therefore, better understanding of thymic function can provide valuable information for improving HSCT outcomes. Recent data have shown that, besides gender and age, a specific single-nucleotide polymorphism affects thymopoiesis and may also influence thymic output post-HSCT, suggesting that the time of precision medicine of thymic function has arrived. Here, we review the current knowledge about thymic role in HSCT and the recent work of genetic control of human thymopoiesis. We also discuss different transplant-related factors that have been associated with impaired thymic recovery and the use of T-cell receptor excision circles (TREC) to assess thymic output, including its clinical significance. Finally, we present therapeutic strategies that could boost thymic recovery post-HSCT.
Assuntos
Transplante de Células-Tronco Hematopoéticas/métodos , Linfopoese/imunologia , Medicina de Precisão , Timo/imunologia , Humanos , Medicina de Precisão/métodos , Medicina de Precisão/tendênciasRESUMO
The identification of specific cell surface glycoprotein receptors for Arg-Gly-Asp-containing extracellular matrix proteins such as fibronectin has focused attention on the role of gangliosides in this process. Is their involvement dependent or independent of the protein receptors? In attachment assays with cells from a human melanoma cell line, titration experiments with an antibody (Mel 3) with specificity for the disialogangliosides GD2 and GD3, used together with a synthetic peptide containing the cell binding sequence Arg-Gly-Asp, show that their joint effect is synergistic. Both the Mel 3 antibody and the synthetic peptide individually cause rapid detachment of melanoma cells from fibronectin substrate but, when used together, much smaller concentrations of both are required to achieve the same effect. The Mel 3 antibody was not nonspecifically reducing receptor binding to the Arg-Gly-Asp sequence since, in binding assays with radiolabeled peptide performed with cells in suspension, very little peptide is bound by the melanoma cells under these conditions but addition of Mel 3, an antibody of IgM isotype, causes a two- to threefold increase in specific binding. The simplest interpretation of these data is that the Mel 3 antibody is causing sufficient clustering of membrane gangliosides in local areas and producing a favorably charged environment to facilitate peptide binding by specific glycoprotein receptors.
Assuntos
Matriz Extracelular/metabolismo , Gangliosídeos/metabolismo , Glicoproteínas/metabolismo , Oligopeptídeos/metabolismo , Complexo Glicoproteico GPIb-IX de Plaquetas , Glicoproteínas da Membrana de Plaquetas , Receptores Imunológicos/metabolismo , Anticorpos Monoclonais/imunologia , Adesão Celular , Membrana Celular/metabolismo , Fibronectinas/metabolismo , Humanos , Imunoglobulina M/imunologia , Melanoma , Oligopeptídeos/imunologia , Receptores de Vitronectina , Células Tumorais CultivadasRESUMO
The role of gamma delta (γδ) T cells in human cytomegalovirus (HCMV) immune surveillance has been the focus of research interest for years. Recent reports have shown a substantial clonal proliferation of γδ T cells in response to HCMV, shedding light on the adaptive immune response of γδ T cells. Nevertheless, most efforts have focused on Vδ2neg γδ T cell subset while less attention has been given to investigate other less common γδ T cell subsets. In this regard, a distinct subpopulation of γδ T cells that expresses the CD8 coreceptor (CD8+ γδ T cells) has not been thoroughly explored. Whether it is implicated in HCMV response and its ability to generate adaptive response has not been thoroughly investigated. In this study, we combined flow cytometry and immune sequencing of the TCR γ-chain (TRG) to analyze in-depth bone marrow (BM) graft γδ T cells from CMV seropositive (CMV+) and CMV seronegative (CMV-) donors. We showed that the frequency of CD8+ γδ T cells was significantly higher in CMV+ grafts compared to CMV- grafts (P < 0.001). Further characterization revealed that CD8+ γδ T cells from CMV+ grafts express Vγ9- and preferentially differentiated from a naive to terminal effector memory phenotype (CD27low/-CD45RO-). In line with these findings, TRG immune sequencing revealed clonal focusing and reduced usage of the Vγ9/JP gene segment in a CMV+ graft. Furthermore, CD8+ γδ T cells showed an enhanced response to TCR/CD3 and cytokine stimulation in contrast to CD8- γδ T cells. We conclude that γδ T cells in BM grafts are reshaped by donor CMV serostatus and highlight the potential adaptive role of CD8+ γδ T cells in HCMV immune response.
RESUMO
Allogeneic hematopoietic stem cell transplantation (HSCT) using αß T-/B-cell-depleted grafts recently emerged as a transplant strategy and highlighted the potential role of γδ T cells on HSCT outcomes. Our aim was to scrutinize available evidence of γδ T-cell impact on relapse, infections, survival, and acute graft-versus-host disease (aGVHD). We performed a systematic review and meta-analysis of studies assessing γδ T cells in HSCT. We searched PubMed, Web of Science, Scopus, and conference abstracts from inception to March 2019 for relevant studies. We included all studies that assessed γδ T cells associated with HSCT. Data were extracted independently by 2 investigators based on strict selection criteria. A random-effects model was used to pool outcomes across studies. Primary outcome was disease relapse. We also assessed infections, survival, and aGVHD incidence. The review was registered with PROSPERO (CRD42019133344). Our search returned 2412 studies, of which 11 (919 patients) were eligible for meta-analysis. Median follow-up was 30 months (interquartile range, 22-32). High γδ T-cell values after HSCT were associated with less disease relapse (risk ratio [RR], 0.58; 95% confidence interval [95% CI], 0.40-0.84; P = .004; I2 = 0%), fewer viral infections (RR, 0.59; 95% CI, 0.43-0.82; P = .002; I2 = 0%) and higher overall (HR, 0.28; 95% CI, 0.18-0.44; P < .00001; I2 = 0%) and disease-free survivals (HR 0.29; 95% CI, 0.18-0.48; P < .00001; I2 = 0%). We found no association between high γδ T-cell values and aGVHD incidence (RR, 0.72; 95% CI, 0.41-1.27; P = .26; I2 = 0%). In conclusion, high γδ T cells after HSCT is associated with a favorable clinical outcome but not with aGVHD development, suggesting that γδ T cells have a significant effect on the success of HSCT. This study was registered with PROSPERO as #CRD42019133344.
Assuntos
Transplante de Células-Tronco Hematopoéticas , Receptores de Antígenos de Linfócitos T gama-delta/metabolismo , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Animais , Biomarcadores , Feminino , Doença Enxerto-Hospedeiro/etiologia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Transplante de Células-Tronco Hematopoéticas/métodos , Humanos , Reconstituição Imune , Infecções/etiologia , Contagem de Linfócitos , Masculino , Prognóstico , Recidiva , Análise de Sobrevida , Resultado do TratamentoRESUMO
In the months that follow autologous hematopoietic stem cell transplantation (AHSCT), lymphopenia drives homeostatic proliferation, leading to oligoclonal expansion of residual cells. Here we evaluated how replicative senescent and exhausted cells associated with clinical outcomes of 25 systemic sclerosis (SSc) patients who underwent AHSCT. Patients were clinically monitored for skin (modified Rodnan's skin score, mRSS) and internal organ involvement and had blood samples collected before and semiannually, until 3 years post-AHSCT, for quantification of telomere length, CD8+CD28- and PD-1+ cells, and serum cytokines. Patients were retrospectively classified as responders (n = 19) and non-responders (n = 6), according to clinical outcomes. At 6 months post-AHSCT, mRSS decreased (P < 0.001) and the pulmonary function stabilized, when compared with pre-transplant measures. In parallel, inflammatory cytokine (IL-6 and IL-1ß) levels and telomere lengths decreased, whereas PD-1 expression on T-cells and the number of CD8+CD28- cells expressing CD57 and FoxP3 increased. After AHSCT, responder patients presented higher PD-1 expression on T- (P < 0.05) and B- (P < 0.01) cells, and lower TGF-ß, IL-6, G-CSF (P < 0.01), and IL-1ß, IL-17A, MIP-1α, and IL-12 (P < 0.05) levels than non-responders. Homeostatic proliferation after AHSCT results in transient telomere attrition and increased numbers of senescent and exhausted cells. High PD-1 expression is associated with better clinical outcomes after AHSCT.
Assuntos
Proliferação de Células , Transplante de Células-Tronco Hematopoéticas , Receptor de Morte Celular Programada 1/sangue , Escleroderma Sistêmico , Homeostase do Telômero , Telômero/metabolismo , Adulto , Linfócitos T CD8-Positivos/metabolismo , Linfócitos T CD8-Positivos/patologia , Citocinas/sangue , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Escleroderma Sistêmico/sangue , Escleroderma Sistêmico/patologia , Escleroderma Sistêmico/terapia , Transplante AutólogoRESUMO
To evaluate the immunological mechanisms associated with clinical outcomes after autologous hematopoietic stem cell transplantation (AHSCT), focusing on regulatory T- (Treg) and B- (Breg) cell immune reconstitution, 31 systemic sclerosis (SSc) patients underwent simultaneous clinical and immunological evaluations over 36-month posttransplantation follow-up. Patients were retrospectively grouped into responders (n = 25) and nonresponders (n = 6), according to clinical response after AHSCT. Thymic function and B-cell neogenesis were respectively assessed by quantification of DNA excision circles generated during T- and B-cell receptor rearrangements. At the 1-year post-AHSCT evaluation of the total set of transplanted SSc patients, thymic rebound led to renewal of the immune system, with higher T-cell receptor (TCR) diversity, positive correlation between recent thymic emigrant and Treg counts, and higher expression of CTLA-4 and GITR on Tregs, when compared with pretransplant levels. In parallel, increased bone marrow output of newly generated naive B-cells, starting at 6 months after AHSCT, renovated the B-cell populations in peripheral blood. At 6 and 12 months after AHSCT, Bregs increased and produced higher interleukin-10 levels than before transplant. When the nonresponder patients were evaluated separately, Treg and Breg counts did not increase after AHSCT, and high TCR repertoire overlap between pre- and posttransplant periods indicated maintenance of underlying disease mechanisms. These data suggest that clinical improvement of SSc patients is related to increased counts of newly generated Tregs and Bregs after AHSCT as a result of coordinated thymic and bone marrow rebound.
Assuntos
Transplante de Células-Tronco Hematopoéticas/métodos , Sistema Imunitário/fisiologia , Escleroderma Sistêmico/terapia , Adulto , Linfócitos B/citologia , Medula Óssea/fisiologia , Feminino , Humanos , Sistema Imunitário/citologia , Contagem de Linfócitos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Escleroderma Sistêmico/imunologia , Escleroderma Sistêmico/mortalidade , Linfócitos T Reguladores/citologia , Timo/citologia , Timo/fisiologia , Transplante Autólogo/métodos , Resultado do Tratamento , Adulto JovemRESUMO
The determinants of clinical responses after autologous hematopoietic stem cell transplantation (aHSCT) in systemic sclerosis (SSc) are still unraveled. We analyzed long-term immune reconstitution (IR) and T cell receptor (TCR) repertoire diversity in 10 SSc patients, with at least 6 years simultaneous clinical and immunological follow-up after aHSCT. Patients were retrospectively classified as long-term responders (A, n = 5) or non-responders (B, n = 5), using modified Rodnan's skin score (mRSS) and forced vital capacity (FVC%). All patients had similar severe SSc before aHSCT. Number of reinjected CD34+ cells was higher in group B versus A (P = 0.02). Long-term mRSS fall >25% was more pronounced in group A (P = 0.004), the only to improve long-term FVC% >10% (P = 0.026). There was an overall trend toward increased of T cell reconstitution in group B versus A. B cells had a positive linear regression slope in group A (LRS = 11.1) and negative in group B (LRS = -11.6). TCR repertoire was disturbed before aHSCT and the percentage of polyclonal families significantly increased at long-term (P = 0.046), with no difference between groups. Despite improved skin score after aHSCT in all SSc patients, pretransplant B cell clonal expansion and faster post-transplant T cell IR in long-term non-responder/relapsing patients call for new therapeutic protocols guided by IR analysis to improve their outcome.
Assuntos
Transplante de Células-Tronco Hematopoéticas , Esclerodermia Difusa/terapia , Subpopulações de Linfócitos T/imunologia , Adulto , Antígenos de Diferenciação de Linfócitos T/análise , Contagem de Células , Feminino , Seguimentos , Sobrevivência de Enxerto , Humanos , Imunofenotipagem , Masculino , Pessoa de Meia-Idade , Esclerodermia Difusa/imunologia , Esclerodermia Difusa/patologia , Índice de Gravidade de Doença , Pele/imunologia , Pele/patologia , Transplante Autólogo , Adulto JovemRESUMO
Autologous hematopoietic stem cell transplantation (AHSCT) increases C-peptide levels and induces insulin independence in patients with type 1 diabetes. This study aimed to investigate how clinical outcomes may associate with the immunological status, especially concerning the balance between immunoregulation and autoreactivity. Twenty-one type 1 diabetes patients were monitored after AHSCT and assessed every 6 months for duration of insulin independence, C-peptide levels, frequencies of islet-specific autoreactive CD8+ T cells (CTL), regulatory lymphocyte subsets, thymic function, and T-cell repertoire diversity. In median follow-up of 78 (range 15-106) months, all patients became insulin-independent, resuming insulin after median of 43 (range 6-100) months. Patients were retrospectively divided into short- or prolonged-remission groups, according to duration of insulin independence. For the entire follow-up, CD3+CD4+ T-cell numbers remained lower than baseline in both groups, whereas CD3+CD8+ T-cell levels did not change, resulting in a CD4/CD8 ratio inversion. Memory CTL comprehended most of T cells detected on long-term follow-up of patients after AHSCT. B cells reconstituted to baseline levels at 2-3 months post-AHSCT in both patient groups. In the prolonged-remission-group, baseline islet-specific T-cell autoreactivity persisted after transplantation, but regulatory T cell counts increased. Patients with lower frequencies of autoreactive islet-specific T cells remained insulin-free longer and presented greater C-peptide levels than those with lower frequencies of these cells. Therefore, immune monitoring identified a subgroup of patients with superior clinical outcome of AHSCT. Our study shows that improved immunoregulation may balance autoreactivity endorsing better metabolic outcomes in patients with lower frequencies of islet-specific T cells. Development of new strategies of AHSCT is necessary to increase frequency and function of T and B regulatory cells and decrease efficiently autoreactive islet-specific T and B memory cells in type 1 diabetes patients undergoing transplantation.