RESUMO
OBJECTIVE: To analyze the clinical characteristics, treatment, and prognosis of adult patients with early T-cell precursor acute lymphoblastic leukemia/lymphoma (ETP-ALL/LBL). METHODS: Clinical data of 113 T lymphoblastic leukemia/lymphoma (T-ALL/LBL) patients from January 2006 to January 2019 were collected from three hematology research centers, including Peking University Third Hospital, the First Medical Center of Chinese PLA General Hospital and Institute of Hematology and Blood Diseases Hospital, Chinese Medical University. The clinical characteristics and prognosis of ETP-ALL/LBL patients were analyzed compared with non-ETP-ALL/LBL patients. RESULTS: In 113 T-ALL/LBL patients, 13 cases (11.5%) were diagnosed as ETP-ALL/LBL, including 11 males, with a median age of 28(18-53) years. Compared with non-ETP-ALL/LBL patients, there were no significant differences in age, sex, incidence of large mediastinal mass, clinical stage, international prognostic index (IPI) score, white blood cell (WBC) count and lactate dehydrogenase (LDH) level among ETP-ALL/LBL patients. Among 13 ETP-ALL/LBL patients, 9 cases (69.2%) achieved complete remission (CR), and there was no statistically significant difference in response rate induced by chemotherapy between ETP-ALL/LBL patients and non-ETP-ALL/LBL patients. Among patients who received chemotherapy without allogeneic hematopoietic stem cell transplantation (allo-HSCT), ETP-ALL/LBL group had a worse 5-year overall survival (OS) rate compared with non-ETP-ALL/LBL group (0 vs 7.1%, P =0.008), while in patients with allo-HSCT, there was no significant difference for 5-year OS rate between the two group (37.5% vs 40.2%, P >0.05). Multivariate Cox regression analysis showed that CR after induction therapy, allo-HSCT, and LDH level were independent prognostic factors affecting T-ALL/LBL patients. CONCLUSION: No significant difference in response rate induced by chemotherapy is observed between ETP-ALL/LBL and non-ETP-ALL/LBL patients. Allo-HSCT consolidation after induction of remission therapy may have significant favorable influence on OS for patients with ETP-ALL/LBL.
Assuntos
Transplante de Células-Tronco Hematopoéticas , Leucemia-Linfoma de Células T do Adulto , Linfoma , Leucemia-Linfoma Linfoblástico de Células Precursoras , Células Precursoras de Linfócitos T , Leucemia-Linfoma Linfoblástico de Células T Precursoras , Adulto , Humanos , Masculino , Pessoa de Meia-Idade , Resposta Patológica Completa , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Leucemia-Linfoma Linfoblástico de Células T Precursoras/terapia , Prognóstico , Estudos Retrospectivos , Feminino , Adolescente , Adulto JovemRESUMO
Objective: To explore the efficacy and safety of Venetoclax combined with multidrug chemotherapy in patients with relapsed or refractory early T-cell precursor acute lymphoblastic leukemia (R/R ETP-ALL) . Methods: This study retrospectively analyzed 15 patients with R/R ETP-ALL who received Venetoclax combined with multidrug chemotherapy from December 2018 to February 2022. Among them, eight cases were combined with demethylated drugs, four cases were combined with demethylated drugs and HAAG chemotherapy regimen, two cases were combined with demethylated drugs and CAG regimen, and one case was combined with Cladribine. Specific usage and dosage of Venetoclax: 100 mg on day 1, 200 mg on day 2, 400 mg on day 3-28, orally; when combined with azole antifungal drugs, dosage was reduced to 100 mg/d. Results: Fifteen patients (10 males and 5 females) with R/R ETP-ALL were treated with Venetoclax and multidrug chemotherapy with a median age of 35 (12-42) years old. Of 4 refractory and 11 relapsed patients, the efficacy was evaluated on the 21th day following combined chemotherapy: the overall response rate, the complete response (CR) rate, and the CR with incomplete hematological recovery (CRi) rate were 67.7% (10/15), 60.0% (9/15), and 6.7% (1/15), respectively. For the overall study population, the 12-month overall survival (OS) rate was 60.0%, and the median OS was 17.7 months. The disease-free survival (DFS) rate of all CR patients at 12 months was 60.0%, and the median DFS did not reach. About 14 patients had â ¢-â £ hematological toxicity, but these adverse reactions were all controllable. No adverse reaction in the nervous system and tumor lysis syndrome occurred in this study, and no adverse reaction of organs above grade â ¢ occurred. Conclusion: Venetoclax combined with multidrug chemotherapy may be a safe and promising treatment option for patients with R/R ETP-ALL.
Assuntos
Leucemia Mieloide Aguda , Células Precursoras de Linfócitos T , Leucemia-Linfoma Linfoblástico de Células T Precursoras , Masculino , Feminino , Humanos , Adulto , Estudos Retrospectivos , Resultado do Tratamento , Compostos Bicíclicos Heterocíclicos com Pontes/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica , Leucemia-Linfoma Linfoblástico de Células T Precursoras/tratamento farmacológico , Leucemia Mieloide Aguda/tratamento farmacológicoRESUMO
BACKGROUND AND OBJECTIVES: Early T-cell precursor (ETP) acute lymphoblastic leukemia/lymphoma (ALL/LBL) is a newly recognized entity of T-lymphoblastic leukemia/lymphoma. The optimal therapeutic approaches to adult patients are poorly studied. PATIENTS AND METHODS: We compared the outcomes of adult's patents with ETP-ALL/LBL who received frontline chemotherapy regimens with other T-ALL/LBL immunophenotypic subtypes. Patients with ETP-ALL/LBL were identified based on CD1a (-), CD8 (-), CD5 (-) (dim), and positivity for 1 or more stem cell or myeloid antigens. RESULTS: Sixty-nine patients were included between the years 2010 and 2021 (19 ETP-T-ALL/LBL; 50 non ETP- T-cell ALL/LBL). The median age was 26 year (IQR: 21, 33). Fifty-six patients presented as ALL, while 16 with lymphoblastic lymphoma. Forty-seven patients achieved complete remission, and 43 were alive at last encounter. The complete remission rate in patients with ETP-ALL/LBL was lower than that of non-ETP-ALL/LBL patients (32% vs. 68%; P = .2), and the MRD at end of induction was significantly higher (26% vs. 6.2%, P < .001), and more likely to receive allo-SCT consolidation in CR1 (95% vs. 40%, P < .001). After a median follow-up of survivors of 48 months (range: 32-74 months), the median overall survival for patients with ETP-ALL/LBL was not reached versus 11.5 months for the non-ETP-ALL/LBL patients (P = .014)). Twenty-six patients receive allo-SCT in CR1. There was no significant difference in overall survival (79% vs. 70%; P = .49) between both transplant-cohorts in both groups. CONCLUSION: ETP-ALL/LBL represents a high-risk disease subtype of adult ALL. Novel treatment strategies are needed to improve treatment outcomes in this patient's population.
Assuntos
Linfoma , Leucemia-Linfoma Linfoblástico de Células Precursoras , Células Precursoras de Linfócitos T , Leucemia-Linfoma Linfoblástico de Células T Precursoras , Adulto , Humanos , Leucemia-Linfoma Linfoblástico de Células T Precursoras/terapia , Prognóstico , Jordânia , Leucemia-Linfoma Linfoblástico de Células Precursoras/diagnóstico , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológicoRESUMO
No abstract available.
Assuntos
Células Precursoras de Linfócitos T , Leucemia-Linfoma Linfoblástico de Células T Precursoras , Humanos , Citometria de Fluxo , Imuno-Histoquímica , Leucemia-Linfoma Linfoblástico de Células T Precursoras/diagnósticoRESUMO
Leukemia stem cells are known to drive tumor progression, drug resistance, microenvironmental shift, and relapse, which would make them a perfect therapeutic target. However, their phenotypic and functional similarity to their normal counterparts leaves limited road maps for their selective elimination. Tremblay et al. recently unraveled the fundamental role of overactivated pSTAT5 as a functional marker of early T cell precursor acute lymphoblastic leukemia stem cells driving leukemic progression and highlighted its potential use as a therapeutic target to prevent fatal outcomes.
Assuntos
Células Precursoras de Linfócitos T , Leucemia-Linfoma Linfoblástico de Células T Precursoras , Humanos , Fator de Transcrição STAT5/metabolismo , Leucemia-Linfoma Linfoblástico de Células T Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células T Precursoras/patologia , Células-Tronco/metabolismo , Células Precursoras de Linfócitos T/metabolismo , Células Precursoras de Linfócitos T/patologiaAssuntos
Linfoma , Células Precursoras de Linfócitos T , Leucemia-Linfoma Linfoblástico de Células T Precursoras , Humanos , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células T Precursoras/patologia , Células Precursoras de Linfócitos T/patologia , Linfoma/patologiaAssuntos
Células Precursoras de Linfócitos T , Leucemia-Linfoma Linfoblástico de Células T Precursoras , Humanos , Fator de Transcrição STAT5/genética , Fator de Transcrição STAT5/metabolismo , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células T Precursoras/tratamento farmacológico , Linfócitos T/metabolismoRESUMO
This article describes a potential treatment for early T-cell precursor acute lymphoblastic leukemia (ETP-ALL), a relatively rare and highly aggressive hematologic malignancy. A 59-year-old woman admitted to our hospital with enlarged cervical lymph nodes, weight loss, abnormal count, and morphology of peripheral blood cells was diagnosed with ETP-ALL according to morphology, immunology, cytogenetics, and molecular biology. The patient initially received two cycles of the VICP regimen, including vincristine, idarubicin, cyclophosphamide, and prednisone, and had a response with positive minimal residual disease (MRD). The patient was then given venetoclax plus the CAG regimen, including aclarubicin, cytosine arabinoside, and granulocyte colony-stimulating factor. After one cycle, the patient achieved complete remission with negative MRD and was eligible for allogeneic hematopoietic stem cell transplantation.
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Transplante de Células-Tronco Hematopoéticas , Leucemia-Linfoma Linfoblástico de Células Precursoras , Células Precursoras de Linfócitos T , Leucemia-Linfoma Linfoblástico de Células T Precursoras , Feminino , Humanos , Pessoa de Meia-Idade , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Aclarubicina , Fator Estimulador de Colônias de Granulócitos , Citarabina , Leucemia-Linfoma Linfoblástico de Células T Precursoras/tratamento farmacológicoRESUMO
BACKGROUND: Early T-cell precursor acute lymphoblastic leukemia (ETP ALL) is a high-risk subgroup of acute lymphoblastic leukemia characterized by unique immune phenotype and disease biology. ETP ALL cells share similarities with hematopoietic stem cells and myeloid progenitor cells. These patients have lower rates of complete remission and overall survival. High BCL2 expression is the main rationale for using venetoclax in ETP ALL. RESULTS: We report the treatment outcomes of 2 patients with ETP ALL who achieved minimal residual disease negative remission with the short course of venetoclax. CONCLUSIONS: Combination therapy of short-course venetoclax with Berlin-Frankfurt-Meunster 95 regimen is an effective regimen for treating patients with ETP ALL.
Assuntos
Leucemia-Linfoma Linfoblástico de Células Precursoras , Células Precursoras de Linfócitos T , Leucemia-Linfoma Linfoblástico de Células T Precursoras , Humanos , Leucemia-Linfoma Linfoblástico de Células T Precursoras/terapia , Resultado do Tratamento , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológicoRESUMO
Interleukin-7 (IL-7) supports the growth and chemoresistance of T-cell acute lymphoblastic leukemia (T-ALL), particularly the early T-cell precursor subtype (ETP-ALL), which frequently has activating mutations of IL-7 signaling. Signal transducer and activator of transcription (STAT5) is an attractive therapeutic target because it is almost universally activated in ETP-ALL, even in the absence of mutations of upstream activators such as the IL-7 receptor (IL-7R), Janus kinase, and Fms-like tyrosine kinase 3 (FLT3). To examine the role of activated STAT5 in ETP-ALL, we have used a Lmo2-transgenic (Lmo2Tg) mouse model in which we can monitor chemoresistant preleukemia stem cells (pre-LSCs) and leukemia stem cells (LSCs) that drive T-ALL development and relapse following chemotherapy. Using IL-7R-deficient Lmo2Tg mice, we show that IL-7 signaling was not required for the formation of pre-LSCs but essential for their expansion and clonal evolution into LSCs to generate T-ALL. Activated STAT5B was sufficient for the development of T-ALL in IL-7R-deficient Lmo2Tg mice, indicating that inhibition of STAT5 is required to block the supportive signals provided by IL-7. To further understand the role of activated STAT5 in LSCs of ETP-ALL, we developed a new transgenic mouse that enables T-cell specific and doxycycline-inducible expression of the constitutively activated STAT5B1∗6 mutant. Expression of STAT5B1∗6 in T cells had no effect alone but promoted expansion and chemoresistance of LSCs in Lmo2Tg mice. Pharmacologic inhibition of STAT5 with pimozide-induced differentiation and loss of LSCs, while enhancing response to chemotherapy. Furthermore, pimozide significantly reduced leukemia burden in vivo and overcame chemoresistance of patient-derived ETP-ALL xenografts. Overall, our results demonstrate that STAT5 is an attractive therapeutic target for eradicating LSCs in ETP-ALL.
Assuntos
Células Precursoras de Linfócitos T , Leucemia-Linfoma Linfoblástico de Células T Precursoras , Humanos , Camundongos , Animais , Fator de Transcrição STAT5/genética , Fator de Transcrição STAT5/metabolismo , Leucemia-Linfoma Linfoblástico de Células T Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células T Precursoras/metabolismo , Interleucina-7/genética , Interleucina-7/metabolismo , Pimozida/uso terapêutico , Camundongos TransgênicosRESUMO
Early T-cell precursor (ETP) acute lymphoblastic leukemia/lymphoma (ALL) is generally considered to be a high-risk subtype. We retrospectively analyzed the clinical outcomes of adult patients diagnosed with ETP-ALL or other T-cell ALL (non-ETP T-ALL). The subjects were 82 patients (ETP-ALL: n = 18, non-ETP T-ALL: n = 64) for whom relevant immunophenotype data needed for classification were available. ETP-ALL patients were older (median age, 50.5 vs. 33.5 years, P = 0.042) and had less mediastinal involvement (27.8 vs. 73.4%, P < 0.001). The rate of complete remission (CR) with the first induction therapy was significantly lower in the ETP group (33.3 vs. 64.0%, P = 0.03), but the CR rate within 2 cycles of chemotherapy did not differ significantly (61.1 vs. 76.6%, P = 0.232). The 3-year overall survival (OS) rate was also similar in both groups (43.2 vs. 45.8%, P = 0.992). The ETP phenotype had no impact on survival in the transplant group or the non-transplant group. A multivariate analysis identified the male sex as a poor prognostic factor (HR: 4.43, P < 0.01), but not the immunophenotype of ETP. The prognosis for adult patients with ETP-ALL was comparable to that of non-ETP T-ALL patients. However, further studies aimed at improving the remission rate for ETP-ALL are needed.
Assuntos
Linfoma , Leucemia-Linfoma Linfoblástico de Células Precursoras , Células Precursoras de Linfócitos T , Leucemia-Linfoma Linfoblástico de Células T Precursoras , Masculino , Humanos , Leucemia-Linfoma Linfoblástico de Células T Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células T Precursoras/diagnóstico , Estudos Retrospectivos , Prognóstico , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológicoRESUMO
Early T-cell precursor acute lymphoblastic leukemia (ETP-ALL) is a recently identified high-risk subgroup of T-cell ALL in children. However, there have been conflicting reports and limited data have been reported in adult patients. We retrospectively analyzed the cytogenetic and molecular characteristics and long-term survival outcomes of adult patients with ETP-ALL versus non-ETP-ALL. We analyzed 58 patients (median age, 35 years [range, 18-76 years]) with newly diagnosed T-cell ALL who received a uniform remission induction and consolidation chemotherapy with suitable samples for genetic analyses. If a donor was available, all patients were recommended allogeneic hematopoietic cell transplantation (allo-HCT) for post-remission therapy. Out of 58 patients, 21 (36.2%) had ETP-ALL. Patients with ETP-ALL were older and had a higher proportion of complex karyotype than non-ETP-ALL. Additionally, more DNMT3A mutations were detected in ETP-ALL, whereas FBXW7 mutations and CDKN2A/CDKN2B deletions were found nearly exclusively in non-ETP-ALL. The overall complete remission (CR) rates were not different between ETP-ALL (95.2%) and non-ETP-ALL (81.1%) and subsequent allo-HCT proceeding rates in CR1 were 61.9% for ETP-ALL and 43.2% for non-ETP-ALL, respectively. The overall prognosis of patients with T-ALL was poor that estimated 5-year overall survival (OS) was 33.3% for ETP-ALL and 29.5% for non-ETP-ALL. In a subgroup analysis of patients treated with allo-HCT in CR1 (n = 29), 5-year OS was 53.8% for ETP-ALL and 55.4% for non-ETP-ALL. Our data showed molecular characteristics of ETP-ALL and non-ETP-ALL and revealed that intensive chemotherapy followed by allo-HCT for post-remission therapy can contribute to preserved survival outcome of adult patients with ETP-ALL.
Assuntos
Transplante de Células-Tronco Hematopoéticas , Células Precursoras de Linfócitos T , Leucemia-Linfoma Linfoblástico de Células T Precursoras , Criança , Humanos , Adulto , Leucemia-Linfoma Linfoblástico de Células T Precursoras/diagnóstico , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células T Precursoras/terapia , Estudos Retrospectivos , Prognóstico , Indução de Remissão , Análise CitogenéticaRESUMO
BACKGROUND: Early T-cell precursor acute lymphoblastic leukemia (ETP-ALL) is a distinct subtype of T-ALL with a unique immunophenotype and high treatment failure rate. The molecular genetic abnormalities and their prognostic impact in ETP-ALL patients are poorly understood. METHODS: The authors performed systematic analyses of the clinicopathologic features with an emphasis on molecular genetic aspects of 32 patients with ETP-ALL. RESULTS: The median age was 43 years (range, 16-71). The blasts were positive for cytoplasmic CD3 and CD7 and negative for CD1a and CD8. Other markers expressed included CD34 (88%), CD33 (72%), CD117 (68%), CD13 (58%), CD5 (partial, 56%), CD2 (38%), CD10 (25%), CD56 (partial, 19%), and CD4 (6%). Cytogenetic analyses revealed a diploid karyotype in 10 patients, simple (1-2) abnormalities in 10 patients, and complex karyotype in 10 patients. Next-generation sequencing for 21 patients demonstrated that all had gene mutations (median, four mutations per patient). The most frequently mutated genes were WT1 (38%), NOTCH1 (29%), NRAS (29%), PHF6 (25%), TP53 (24%), ASXL1 (19%), FLT3 (19%), and IKZF1 (19%). All patients except one received multi-agent chemotherapy, and 22 patients underwent allogeneic stem cell transplantation. Thrombocytopenia, an abnormal karyotype, and TP53 mutation were associated with markedly shortened overall survival. Stem cell transplantation significantly improved overall survival. CONCLUSIONS: Patients with ETP-ALL often have high mutation burden with increased genomic instability. TP53 mutation was the only molecular prognostic marker and was associated with complex karyotype and greater than or equal to five mutations. These patients may benefit from stem cell transplantation, and recurrent gene mutations may be novel therapeutic markers.
Assuntos
Transplante de Células-Tronco Hematopoéticas , Células Precursoras de Linfócitos T , Leucemia-Linfoma Linfoblástico de Células T Precursoras , Humanos , Leucemia-Linfoma Linfoblástico de Células T Precursoras/terapia , Leucemia-Linfoma Linfoblástico de Células T Precursoras/tratamento farmacológico , Imunofenotipagem , PrognósticoRESUMO
T lymphocytes (T cells) are essential components of the adaptive immune system; they serve multiple functions in responses to pathogens and to ensure immune homeostasis. Written for readers first entering this field of study, this chapter is a brief overview of the development of T cells in the thymus, from the entry of thymus-settling bone marrow-derived precursors to the egress of mature T cells. Surveyed topics include the differentiation and expansion of early precursors, the generation of the T cell antigen receptor repertoire, the selection of αß T cell precursors, and their acquisition of functional competency.
Assuntos
Células Precursoras de Linfócitos T , Timo , Antígenos , Diferenciação Celular , Receptores de Antígenos de Linfócitos T , Receptores de Antígenos de Linfócitos T alfa-betaRESUMO
The translocation t (12;17) (p13; q21) is a rare cytogenetic event most commonly described in pre-B- acute lymphoblastic leukaemia and acute myeloid leukaemia. We identified a child with an immunophenotype of Early T Cell Precursor Acute Lymphoblastic Leukaemia ETP- ALL having t (12;17) (p13; q21) translocation as the primary karyotypic anomaly. The association of t (12;17) (p13; q21) with ETP-ALL has not been described previously in literature. The possibility of it being a novel genetic abnormality or a part of the newly described entity of ETP/myeloid MPAL is being discussed. Detection of such abnormalities can alter the prognosis of ETP-ALL. Key words: ETP-ALL , t(12;17) (p13;q21) translocation, ETP- MPAL.
Assuntos
Leucemia Mieloide Aguda , Linfoma não Hodgkin , Leucemia-Linfoma Linfoblástico de Células Precursoras , Células Precursoras de Linfócitos T , Criança , Humanos , FenótipoRESUMO
INTRODUCTION: Lassa virus is a priority pathogen for vaccine research and development, however the duration of cellular immunity and protection in Lassa fever (LF) survivors remains unclear. METHODS: We investigated Lassa virus specific CD8+ T cell responses in 93 LF survivors. Peripheral blood mononuclear cells from these individuals were infected with recombinant vesicular stomatitis virus encoding Lassa virus antigens and virus specific T cell responses were measured after 18-hour incubation. Participants who had undetectable CD8+ T cell response underwent further analysis using a 10-day T cell proliferation assays to evaluate for low T cell precursor frequency. RESULTS: Forty-five of the 93 LF survivors did not have a Lassa virus specific CD8+ T cell response. Of those with responses and a known date of onset of LF (N = 11), 9 had LF within the last ten years. Most participants without a measurable CD8+ T cell response were more than 10 years removed from a clinical history of LF (N = 14/16). Fourteen of 21 patients (67%) with undetectable CD8+ T cell response had a measurable Lassa virus specific CD8+ T cell response with the 10-day assay. DISCUSSION: Despite reports of strong CD8+ T cell responses during acute Lassa virus infection, circulating Lassa virus-specific CD8+ T cells declined to undetectable levels in most Lassa fever survivors after ten years when evaluated with an 18-hour T cell stimulation. However, when Lassa virus-specific T cells were expanded prior to restimulation, a Lassa virus-specific CD8+ T cell response could be detected in many if the samples that were negative in the 18-hour stimulation assay, suggesting that prolonged cellular immunity does exist in Lassa fever survivors at low frequencies.
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Febre Lassa , Células Precursoras de Linfócitos T , Humanos , Vírus Lassa , Leucócitos Mononucleares , Imunidade , Linfócitos T CD8-PositivosRESUMO
ABSTRACT: Early T-cell precursor ALL (acute lymphoblastic leukemia) is a rare type of childhood and adult T-cell ALL. Disease recurrence is common within 2 years from the time of initial diagnosis. Outcomes of relapse have been characterized through risk stratification schemes, and one of the major determinants of overall survival is the overall tumor burden and sites of relapse. Although testicular recurrence is common; Peripheral nerve as a site of recurrence is relatively rare. We present a case of early T-cell ALL on maintenance therapy with multifocal relapse on FDG PET/CT in the cervical lymph nodes, the testis, and the left sciatic nerve. Bone marrow and flow cytometry confirmed the relapse.
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Fluordesoxiglucose F18 , Células Precursoras de Linfócitos T , Masculino , Adulto , Humanos , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Tomografia por Emissão de Pósitrons , RecidivaRESUMO
CD8+ T cells that respond to chronic viral infections or cancer are characterized by the expression of inhibitory receptors such as programmed cell death protein 1 (PD-1) and by the impaired production of cytokines. This state of restrained functionality-which is referred to as T cell exhaustion1,2-is maintained by precursors of exhausted T (TPEX) cells that express the transcription factor T cell factor 1 (TCF1), self-renew and give rise to TCF1- exhausted effector T cells3-6. Here we show that the long-term proliferative potential, multipotency and repopulation capacity of exhausted T cells during chronic infection are selectively preserved in a small population of transcriptionally distinct CD62L+ TPEX cells. The transcription factor MYB is not only essential for the development of CD62L+ TPEX cells and maintenance of the antiviral CD8+ T cell response, but also induces functional exhaustion and thereby prevents lethal immunopathology. Furthermore, the proliferative burst in response to PD-1 checkpoint inhibition originates exclusively from CD62L+ TPEX cells and depends on MYB. Our findings identify CD62L+ TPEX cells as a stem-like population that is central to the maintenance of long-term antiviral immunity and responsiveness to immunotherapy. Moreover, they show that MYB is a transcriptional orchestrator of two fundamental aspects of exhausted T cell responses: the downregulation of effector function and the long-term preservation of self-renewal capacity.