Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 130
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
J Immunol ; 208(3): 562-570, 2022 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-35031578

RESUMO

Aging is associated with functional deficits in the naive T cell compartment, which compromise the generation of de novo immune responses against previously unencountered Ags. The mechanisms that underlie this phenomenon have nonetheless remained unclear. We found that naive CD8+ T cells in elderly humans were prone to apoptosis and proliferated suboptimally in response to stimulation via the TCR. These abnormalities were associated with dysregulated lipid metabolism under homeostatic conditions and enhanced levels of basal activation. Importantly, reversal of the bioenergetic anomalies with lipid-altering drugs, such as rosiglitazone, almost completely restored the Ag responsiveness of naive CD8+ T cells. Interventions that favor lipid catabolism may therefore find utility as adjunctive therapies in the elderly to promote vaccine-induced immunity against targetable cancers and emerging pathogens, such as seasonal influenza viruses and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).


Assuntos
Envelhecimento/imunologia , Linfócitos T CD8-Positivos/imunologia , Imunocompetência/efeitos dos fármacos , Metabolismo dos Lipídeos , Adulto , Idoso , Idoso de 80 Anos ou mais , Apoptose , Linfócitos T CD8-Positivos/metabolismo , COVID-19/imunologia , Vacinas Anticâncer/imunologia , Divisão Celular , Feminino , Fenofibrato/farmacologia , Glucose/metabolismo , Antígeno HLA-A2/imunologia , Humanos , Hipolipemiantes/farmacologia , Hipolipemiantes/uso terapêutico , Influenza Humana/imunologia , Metabolismo dos Lipídeos/efeitos dos fármacos , Ativação Linfocitária , Antígeno MART-1/química , Antígeno MART-1/imunologia , Masculino , Pessoa de Meia-Idade , Neoplasias/imunologia , Fragmentos de Peptídeos/imunologia , Rosiglitazona/farmacologia , Método Simples-Cego , Vacinação , Vacinas Virais/imunologia , Adulto Jovem
2.
Proc Natl Acad Sci U S A ; 118(22)2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-34050021

RESUMO

Natural killer (NK) cells are major antileukemic immune effectors. Leukemic blasts have a negative impact on NK cell function and promote the emergence of phenotypically and functionally impaired NK cells. In the current work, we highlight an accumulation of CD56-CD16+ unconventional NK cells in acute myeloid leukemia (AML), an aberrant subset initially described as being elevated in patients chronically infected with HIV-1. Deep phenotyping of NK cells was performed using peripheral blood from patients with newly diagnosed AML (n = 48, HEMATOBIO cohort, NCT02320656) and healthy subjects (n = 18) by mass cytometry. We showed evidence of a moderate to drastic accumulation of CD56-CD16+ unconventional NK cells in 27% of patients. These NK cells displayed decreased expression of NKG2A as well as the triggering receptors NKp30 and NKp46, in line with previous observations in HIV-infected patients. High-dimensional characterization of these NK cells highlighted a decreased expression of three additional major triggering receptors required for NK cell activation, NKG2D, DNAM-1, and CD96. A high proportion of CD56-CD16+ NK cells at diagnosis was associated with an adverse clinical outcome and decreased overall survival (HR = 0.13; P = 0.0002) and event-free survival (HR = 0.33; P = 0.018) and retained statistical significance in multivariate analysis. Pseudotime analysis of the NK cell compartment highlighted a disruption of the maturation process, with a bifurcation from conventional NK cells toward CD56-CD16+ NK cells. Overall, our data suggest that the accumulation of CD56-CD16+ NK cells may be the consequence of immune escape from innate immunity during AML progression.


Assuntos
Citometria de Fluxo/métodos , Células Matadoras Naturais/imunologia , Leucemia Mieloide Aguda/imunologia , Leucemia Mieloide Aguda/patologia , Antígenos CD/imunologia , Humanos , Imunofenotipagem , Ativação Linfocitária/imunologia , Indução de Remissão , Resultado do Tratamento
3.
Gut ; 72(4): 699-709, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-35803702

RESUMO

OBJECTIVE: T cells are major effectors of the antitumoural immune response. Their activation by tumour-associated antigens can unleash their proliferation and cytotoxic functions, leading to tumour cell elimination. However, tumour-related immunosuppressive mechanisms including the overexpression of immune checkpoints like programmed cell death protein-1 (PD-1), are also engaged, promoting immune escape. Current immunotherapies targeting these pathways have demonstrated weak efficacy in colorectal cancer (CRC). It is thus crucial to find new targets for immunotherapy in this cancer type. DESIGN: In a prospective cohort of patients with CRC, we investigated the phenotype of tumour-related and non-tumour related intestinal T cells (n=44), particularly the adenosinergic pathway, correlating with clinical phenotype. An autologous coculture model was developed between patient-derived primary tumour spheroids and their autologous tumour-associated lymphocytes. We used this relevant model to assess the effects of CD39 blockade on the antitumour T cell response. RESULTS: We show the increased expression of CD39, and its co-expression with PD-1, on tumour infiltrating T cells compared with mucosal lymphocytes. CD39 expression was higher in the right colon and early-stage tumours, thus defining a subset of patients potentially responsive to CD39 blockade. Finally, we demonstrate in autologous conditions that CD39 blockade triggers T cell infiltration and tumour spheroid destruction in cocultures. CONCLUSION: In CRC, CD39 is strongly expressed on tumour infiltrating lymphocytes and its inhibition represents a promising therapeutic strategy for treating patients.


Assuntos
Neoplasias Colorretais , Linfócitos T , Humanos , Receptor de Morte Celular Programada 1/metabolismo , Estudos Prospectivos , Intestinos/patologia , Neoplasias Colorretais/patologia
4.
Kidney Int ; 103(1): 70-76, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36108807

RESUMO

Long-term multilineage hematopoietic donor chimerism occurs sporadically in patients who receive a transplanted solid organ enriched in lymphoid tissues such as the intestine or liver. There is currently no evidence for the presence of kidney-resident hematopoietic stem cells in any mammal species. Graft-versus-host-reactive donor T cells promote engraftment of graft-derived hematopoietic stem cells by making space in the bone marrow. Here, we report full (over 99%) multilineage, donor-derived hematopoietic chimerism in a pediatric kidney transplant recipient with syndromic combined immune deficiency that leads to transplant tolerance. Interestingly, we found that the human kidney-derived hematopoietic stem cells took up long-term residence in the recipient's bone marrow and gradually replaced their host counterparts, leading to blood type conversion and full donor chimerism of both lymphoid and myeloid lineages. Thus, our findings highlight the existence of human kidney-derived hematopoietic stem cells with a self-renewal ability able to support multilineage hematopoiesis.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Células-Tronco Hematopoéticas , Animais , Humanos , Criança , Medula Óssea , Linfócitos T , Hematopoese , Rim , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Transplante de Medula Óssea , Mamíferos
5.
J Immunol ; 207(3): 809-823, 2021 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-34282003

RESUMO

The transcription factor promyelocytic leukemia zinc finger (PLZF) is encoded by the BTB domain-containing 16 (Zbtb16) gene. Its repressor function regulates specific transcriptional programs. During the development of invariant NKT cells, PLZF is expressed and directs their effector program, but the detailed mechanisms underlying PLZF regulation of multistage NKT cell developmental program are not well understood. This study investigated the role of acetylation-induced PLZF activation on NKT cell development by analyzing mice expressing a mutant form of PLZF mimicking constitutive acetylation (PLZFON) mice. NKT populations in PLZFON mice were reduced in proportion and numbers of cells, and the cells present were blocked at the transition from developmental stage 1 to stage 2. NKT cell subset differentiation was also altered, with T-bet+ NKT1 and RORγt+ NKT17 subsets dramatically reduced and the emergence of a T-bet-RORγt- NKT cell subset with features of cells in early developmental stages rather than mature NKT2 cells. Preliminary analysis of DNA methylation patterns suggested that activated PLZF acts on the DNA methylation signature to regulate NKT cells' entry into the early stages of development while repressing maturation. In wild-type NKT cells, deacetylation of PLZF is possible, allowing subsequent NKT cell differentiation. Interestingly, development of other innate lymphoid and myeloid cells that are dependent on PLZF for their generation is not altered in PLZFON mice, highlighting lineage-specific regulation. Overall, we propose that specific epigenetic control of PLZF through acetylation levels is required to regulate normal NKT cell differentiation.


Assuntos
Fatores de Transcrição Kruppel-Like , Células T Matadoras Naturais , Acetilação , Animais , Diferenciação Celular , Imunidade Inata , Fatores de Transcrição Kruppel-Like/genética , Fatores de Transcrição Kruppel-Like/metabolismo , Linfócitos/metabolismo , Camundongos , Células T Matadoras Naturais/metabolismo , Proteína com Dedos de Zinco da Leucemia Promielocítica
6.
Br J Dermatol ; 186(6): 1010-1025, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35041763

RESUMO

BACKGROUND: Mogamulizumab, an anti-CCR4 monoclonal antibody, has been shown to increase progression-free survival in cutaneous T-cell lymphoma. OBJECTIVES: We hypothesized that besides the targeted depletion of Sézary cells (SCs), mogamulizumab may reshape the immune tumour microenvironment. METHODS: Both malignant and benign compartments from 26 patients with B2 stage Sézary syndrome before mogamulizumab initiation were prospectively analysed using KIR3DL2 and TCRVß markers, serological markers and molecular assessments of clonality. RESULTS: Prior to mogamulizumab, the benign subset of CD4+ T cells displayed exhausted phenotypes, with an increased gradient in programmed death-1, TIGIT, DNAM-1, CD27, CD28 and CD70 expression from age-matched controls to patients' benign CD4+ T cells and to SCs. All patients presented SCs with heterogeneous phenotypes, and differential expression of individual markers was found within distinct malignant subsets. Early complete blood response was observed in 17 of 26 patients and was associated with higher baseline CCR4 expression. A drastic decrease in benign T cells and activated regulatory T-cell counts was observed during the first 4 weeks. Long-term follow-up revealed the emergence of an immune restoration involving CD8+ and naive and stem memory CD4+ T cells, with almost complete disappearance of exhausted lymphocytes. Development of resistance or tumour escape to mogamulizumab was associated with the emergence of CCR4- SCs in blood and skin, displaying significant changes in their heterogeneity patterns, and not explained only by mutations within CCR4 coding regions. CONCLUSIONS: Mogamulizumab likely contributes to the restoration of efficient immunity and reshapes not only the malignant lymphocyte subset but also the benign subset. These results have potential implications for optimal therapeutic sequences and/or combinations. What is already known about this topic? Management of Sézary syndrome (SS) involves successive therapies that participate as cause and consequence in the emergence of resistant clones, on a background of immunodeficiency. We and others have reported the complex and dynamic heterogeneity of Sézary cells (SCs) during disease progression. Mogamulizumab therapy, by targeting the skin-homing receptor CCR4, mainly expressed by SCs, has been shown to increase progression-free survival in patients with SS. What does this study add? Using multicolour flow cytometry, we provide quantification of CCR4 and immune checkpoint molecules on malignant SCs and benign CD4+ T cells from patients with SS, separated using KIR3DL2 and TCRVß expression. Mogamulizumab is not only aimed at eradicating malignant SCs but potentially contributes to the restoration of efficient immunity. Tumour escape is associated with the emergence of CCR4- SCs, not explained only by mutations within CCR4 coding regions.


Assuntos
Reconstituição Imune , Linfoma Cutâneo de Células T , Síndrome de Sézary , Neoplasias Cutâneas , Anticorpos Monoclonais Humanizados , Humanos , Linfoma Cutâneo de Células T/patologia , Receptores KIR3DL2 , Síndrome de Sézary/tratamento farmacológico , Síndrome de Sézary/genética , Neoplasias Cutâneas/tratamento farmacológico , Neoplasias Cutâneas/genética , Microambiente Tumoral
7.
Nat Methods ; 15(8): 623-630, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-30065364

RESUMO

Lymph nodes (LNs) facilitate the cellular interactions that orchestrate immune responses. Human immune system (HIS) mice are powerful tools for interrogation of human immunity but lack secondary lymphoid tissue (SLT) as a result of a deficiency in Il2rg-dependent lymphoid tissue inducer cells. To restore LN development, we induced expression of thymic-stromal-cell-derived lymphopoietin (TSLP) in a Balb/c Rag2-/-Il2rg-/-SirpaNOD (BRGS) HIS mouse model. The resulting BRGST HIS mice developed a full array of LNs with compartmentalized human B and T cells. Compared with BRGS HIS mice, BRGST HIS mice have a larger thymus, more mature B cells, and abundant IL-21-producing follicular helper T (TFH) cells, and show enhanced antigen-specific responses. Using BRGST HIS mice, we demonstrated that LN TFH cells are targets of acute HIV infection and represent a reservoir for latent HIV. In summary, BRGST HIS mice reflect the effects of SLT development on human immune responses and provide a model for visualization and interrogation of regulators of immunity.


Assuntos
Linfonodos/crescimento & desenvolvimento , Linfonodos/imunologia , Animais , Linfócitos B/citologia , Linfócitos B/imunologia , Citocinas/genética , Citocinas/imunologia , Feminino , Infecções por HIV/imunologia , HIV-1 , Humanos , Switching de Imunoglobulina , Subunidade gama Comum de Receptores de Interleucina/deficiência , Subunidade gama Comum de Receptores de Interleucina/genética , Linfonodos/citologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Modelos Imunológicos , Linfócitos T/citologia , Linfócitos T/imunologia , Latência Viral/imunologia , Linfopoietina do Estroma do Timo
8.
Int Immunol ; 32(2): 105-116, 2020 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-31565740

RESUMO

Invariant natural killer T (iNKT) cells expressing the retinoic acid receptor-related orphan receptor γt (RORγt) and producing IL-17 represent a minor subset of CD1d-restricted iNKT cells (iNKT17) in C57BL/6J (B6) mice. We aimed in this study to define the reasons for their low distribution and the sequence of events accompanying their normal thymic development. We found that RORγt+ iNKT cells have higher proliferation potential and a greater propensity to apoptosis than RORγt- iNKT cells. These cells do not likely reside in the thymus indicating that thymus emigration, and higher apoptosis potential, could contribute to RORγt+ iNKT cell reduced thymic distribution. Ontogeny studies suggest that mature HSAlow RORγt+ iNKT cells might develop through developmental stages defined by a differential expression of CCR6 and CD138 during which RORγt expression and IL-17 production capabilities are progressively acquired. Finally, we found that RORγt+ iNKT cells perceive a strong TCR signal that could contribute to their entry into a specific 'Th17 like' developmental program influencing their survival and migration. Overall, our study proposes a hypothetical thymic developmental sequence for iNKT17 cells, which could be of great use to study molecular mechanisms regulating this developmental program.


Assuntos
Células T Matadoras Naturais/imunologia , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/imunologia , Animais , Feminino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/deficiência
9.
Eur J Immunol ; 49(6): 894-910, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30912587

RESUMO

It is established that iNKT cells are a cell type that require strong TCR signal for their proper development and represent a model for thymic agonist selection. The nature of the signal perceived by iNKT cells promoting their specification is not well understood. To address this question, we analyzed iNKT cell development in relevant TCR Vα14-Jα18 alpha chain transgenic mice (Vα14Tg). In CD4-Vα14Tg mice, where the transgene is driven by CD4 promoter, we identified a block in iNKT cell development at early developmental stages due to a reduced expression of key transcription factors accompanied with a reduced TCR expression levels. This indicates that TCR signal strength control iNKT cell differentiation. Importantly, we found in WT mice that early precursors of iNKT cells express higher TCR levels compared to positively selected precursors of mainstream T cells showing that TCR levels could contribute to the strength of iNKT cell TCR signaling. Overall, our study highlights TCR signal strength associated with a higher TCR density as an important regulator of iNKT cell lineage specification.


Assuntos
Células T Matadoras Naturais/citologia , Receptores de Antígenos de Linfócitos T alfa-beta/metabolismo , Subpopulações de Linfócitos T/citologia , Animais , Diferenciação Celular/imunologia , Linhagem da Célula/imunologia , Camundongos , Camundongos Transgênicos , Células T Matadoras Naturais/imunologia , Células T Matadoras Naturais/metabolismo , Receptores de Antígenos de Linfócitos T alfa-beta/imunologia , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo
10.
Eur J Immunol ; 49(6): 954-965, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30888052

RESUMO

Human immune system (HIS) mouse models provide a robust in vivo platform to study human immunity. Nevertheless, the signals that guide human lymphocyte differentiation in HIS mice remain poorly understood. Here, we have developed a novel Balb/c Rag2-/- Il2rg-/- SirpaNOD (BRGS) HIS mouse model expressing human HLA-A2 and -DR2 transgenes (BRGSA2DR2). When comparing BRGS and BRGSA2DR2 HIS mice engrafted with human CD34+ stem cells, a more rapid emergence of T cells in the circulation of hosts bearing human HLA was shown, which may reflect a more efficient human T-cell development in the mouse thymus. Development of CD4+ and CD8+ T cells was accelerated in BRGSA2DR2 HIS mice and generated more balanced B and T-cell compartments in peripheral lymphoid organs. Both B- and T-cell function appeared enhanced in the presence of human HLA transgenes with higher levels of class switched Ig, increased percentages of polyfunctional T cells and clear evidence for antigen-specific T-cell responses following immunization. Taken together, the presence of human HLA class I and II molecules can improve multiple aspects of human B- and T-cell homeostasis and function in the BRGS-based HIS mouse model.


Assuntos
Modelos Animais de Doenças , Linfopoese/imunologia , Camundongos Transgênicos , Linfócitos T , Animais , Linfócitos B/citologia , Linfócitos B/imunologia , Diferenciação Celular/imunologia , Antígeno HLA-A2/genética , Antígeno HLA-A2/imunologia , Antígeno HLA-DR2/genética , Antígeno HLA-DR2/imunologia , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Linfócitos T/citologia , Linfócitos T/imunologia
11.
Cancer Immunol Immunother ; 68(10): 1561-1572, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31494742

RESUMO

Preclinical and clinical studies have suggested that cancer treatment with antitumor antibodies induces a specific adaptive T cell response. A central role in this process has been attributed to CD4+ T cells, but the relevant T cell epitopes, mostly derived from non-mutated self-antigens, are largely unknown. In this study, we have characterized human CD20-derived epitopes restricted by HLA-DR1, HLA-DR3, HLA-DR4, and HLA-DR7, and investigated whether T cell responses directed against CD20-derived peptides can be elicited in human HLA-DR-transgenic mice and human samples. Based on in vitro binding assays to recombinant human MHC II molecules and on in vivo immunization assays in H-2 KO/HLA-A2+-DR1+ transgenic mice, we have identified 21 MHC II-restricted long peptides derived from intracellular, membrane, or extracellular domains of the human non-mutated CD20 protein that trigger in vitro IFN-γ production by PBMCs and splenocytes from healthy individuals and by PBMCs from follicular lymphoma patients. These CD20-derived MHC II-restricted peptides could serve as a therapeutic tool for improving and/or monitoring anti-CD20 T cell activity in patients treated with rituximab or other anti-CD20 antibodies.


Assuntos
Antígenos CD20/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfoma/tratamento farmacológico , Animais , Feminino , Cadeias HLA-DRB1/imunologia , Humanos , Interferon gama/biossíntese , Linfoma/imunologia , Camundongos , Rituximab/uso terapêutico
12.
J Immunol ; 198(3): 1172-1182, 2017 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-28031333

RESUMO

NK cells, which are highly enriched in the liver, are potent regulators of antiviral T cells and immunopathology in persistent viral infection. We investigated the role of the NKG2D axis in T cell/NK cell interactions in hepatitis B. Activated and hepatitis B virus (HBV)-specific T cells, particularly the CD4 fraction, expressed NKG2D ligands (NKG2DL), which were not found on T cells from healthy controls (p < 0.001). NKG2DL-expressing T cells were strikingly enriched within HBV-infected livers compared with the periphery or to healthy livers (p < 0.001). NKG2D+NK cells were also increased and preferentially activated in the HBV-infected liver (p < 0.001), in direct proportion to the percentage of MICA/B-expressing CD4 T cells colocated within freshly isolated liver tissue (p < 0.001). This suggests that NKG2DL induced on T cells within a diseased organ can calibrate NKG2D-dependent activation of local NK cells; furthermore, NKG2D blockade could rescue HBV-specific and MICA/B-expressing T cells from HBV-infected livers. To our knowledge, this is the first ex vivo demonstration that non-virally infected human T cells can express NKG2DL, with implications for stress surveillance by the large number of NKG2D-expressing NK cells sequestered in the liver.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Hepatite B Crônica/imunologia , Células Matadoras Naturais/imunologia , Fígado/imunologia , Subfamília K de Receptores Semelhantes a Lectina de Células NK/fisiologia , Adulto , Comunicação Celular , Células Cultivadas , Feminino , Humanos , Ligantes , Fígado/virologia , Ativação Linfocitária , Masculino , Subfamília K de Receptores Semelhantes a Lectina de Células NK/antagonistas & inibidores
13.
Blood ; 128(15): 1979-1986, 2016 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-27549307

RESUMO

Graft-versus-host disease (GVHD) is among the most challenging complications in unrelated donor hematopoietic cell transplantation (HCT). The highly polymorphic MHC class I chain-related gene A, MICA, encodes a stress-induced glycoprotein expressed primarily on epithelia. MICA interacts with the invariant activating receptor NKG2D, expressed by cytotoxic lymphocytes, and is located in the MHC, next to HLA-B Hence, MICA has the requisite attributes of a bona fide transplantation antigen. Using high-resolution sequence-based genotyping of MICA, we retrospectively analyzed the clinical effect of MICA mismatches in a multicenter cohort of 922 unrelated donor HLA-A, HLA-B, HLA-C, HLA-DRB1, and HLA-DQB1 10/10 allele-matched HCT pairs. Among the 922 pairs, 113 (12.3%) were mismatched in MICA MICA mismatches were significantly associated with an increased incidence of grade III-IV acute GVHD (hazard ratio [HR], 1.83; 95% confidence interval [CI], 1.50-2.23; P < .001), chronic GVHD (HR, 1.50; 95% CI, 1.45-1.55; P < .001), and nonelapse mortality (HR, 1.35; 95% CI, 1.24-1.46; P < .001). The increased risk for GVHD was mirrored by a lower risk for relapse (HR, 0.50; 95% CI, 0.43-0.59; P < .001), indicating a possible graft-versus-leukemia effect. In conclusion, when possible, selecting a MICA-matched donor significantly influences key clinical outcomes of HCT in which a marked reduction of GVHD is paramount. The tight linkage disequilibrium between MICA and HLA-B renders identifying a MICA-matched donor readily feasible in clinical practice.


Assuntos
Doença Enxerto-Hospedeiro , Antígenos HLA/genética , Transplante de Células-Tronco Hematopoéticas , Antígenos de Histocompatibilidade Classe I/genética , Teste de Histocompatibilidade , Desequilíbrio de Ligação , Doença Aguda , Adolescente , Adulto , Idoso , Aloenxertos , Criança , Pré-Escolar , Doença Crônica , Feminino , Doença Enxerto-Hospedeiro/epidemiologia , Doença Enxerto-Hospedeiro/etiologia , Doença Enxerto-Hospedeiro/genética , Doença Enxerto-Hospedeiro/prevenção & controle , Humanos , Incidência , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Subfamília K de Receptores Semelhantes a Lectina de Células NK/genética , Estudos Retrospectivos
14.
Clin Immunol ; 183: 325-335, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28943400

RESUMO

Functional immune responses are increasingly important for clinical studies, providing in depth biomarker information to assess immunotherapy or vaccination. Incorporating functional immune assays into routine clinical practice has remained limited due to challenges in standardizing sample preparation. We recently described the use of a whole blood syringe-based system, TruCulture®, which permits point-of-care standardized immune stimulation. Here, we report on a multi-center clinical study in seven FOCIS Centers of Excellence to directly compare TruCulture to conventional PBMC methods. Whole blood and PBMCs from healthy donors were exposed to LPS, anti-CD3 anti-CD28 antibodies, or media alone. 55 protein analytes were analyzed centrally by Luminex multi-analyte profiling in a CLIA-certified laboratory. TruCulture responses showed greater reproducibility and improved the statistical power for monitoring differential immune response activation. The use of TruCulture addresses a major unmet need through a robust and flexible method for immunomonitoring that can be reproducibly applied in multi-center clinical studies. ONE SENTENCE SUMMARY: A multi-center study revealed greater reproducibility from whole blood stimulation systems as compared to PBMC stimulation for studying induced immune responses.


Assuntos
Anticorpos/imunologia , Citocinas/metabolismo , Regulação da Expressão Gênica/imunologia , Testes Imunológicos/instrumentação , Testes Imunológicos/métodos , Biomarcadores/sangue , Doadores de Sangue , Complexo CD3/imunologia , Antígenos CD8/imunologia , Citocinas/genética , Humanos , Lipopolissacarídeos/toxicidade , Sistemas Automatizados de Assistência Junto ao Leito
15.
Eur J Immunol ; 46(5): 1291-9, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-26865269

RESUMO

Humanized mice harboring human immune systems (HIS) represent a platform to study immune responses against pathogens and to screen vaccine candidates and novel immunotherapeutics. Innate and adaptive immune responses are suboptimal in HIS mice, possibly due to poor reconstitution of human antigen-presenting cells, including dendritic cells (DCs). DC homeostasis is regulated by cytokine availability, and Flt3-ligand (Flt3L) is one factor that conditions this process. Mouse myelopoiesis is essentially normal in most current HIS models. As such, developing mouse myeloid cells may limit human DC reconstitution by reducing available Flt3L and by cellular competition for specific "niches." To address these issues, we created a novel HIS model that compromises host myeloid cell development via deficiency in the receptor tyrosine kinase Flk2/Flt3. In Balb/c Rag2(-/-) Il2rg(-/-) Flt3(-/-) (BRGF) recipients, human conventional DCs and plasmacytoid DCs develop from hCD34(+) precursors and can be specifically boosted with exogenous Flt3L. Human DCs that develop in this context normally respond to TLR stimulation, and improved human DC homeostasis is associated with increased numbers of human NK and T cells. This new HIS-DC model should provide a means to dissect human DC differentiation and represents a novel platform to screen immune adjuvants and DC targeting therapies.


Assuntos
Diferenciação Celular , Células Dendríticas/imunologia , Células Dendríticas/fisiologia , Tirosina Quinase 3 Semelhante a fms/deficiência , Adjuvantes Imunológicos , Animais , Homeostase , Humanos , Imunidade Inata , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Células Mieloides/fisiologia , Células T Matadoras Naturais/fisiologia , Linfócitos T/fisiologia , Tirosina Quinase 3 Semelhante a fms/genética
16.
Haematologica ; 102(8): 1368-1377, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28522576

RESUMO

Despite persistence of leukemic stem cells, patients with chronic myeloid leukemia who achieve and maintain deep molecular responses may successfully stop the tyrosine kinase inhibitor imatinib. However, questions remain unanswered regarding the biological basis of molecular relapse after imatinib cessation. In IMMUNOSTIM, we monitored 51 patients from the French Stop IMatinib trial for peripheral blood T cells and natural killer cells. Molecular relapse-free survival at 24 months was 45.1% (95% CI: 31.44%-58.75%). At the time of imatinib discontinuation, non-relapsing patients had significantly higher numbers of natural killer cells of the cytotoxic CD56dim subset than had relapsing patients, while CD56bright natural killer cells, T cells and their subsets did not differ significantly. Furthermore, the CD56dim natural killer-cell count was an independent prognostic factor of molecular-relapse free survival in a multivariate analysis. However, expression of natural killer-cell activating receptors, BCR-ABL1+ leukemia cell line K562-specific degranulation and cytokine-induced interferon-gamma secretion were decreased in non-relapsing and relapsing patients as compared with healthy individuals. After imatinib cessation, the natural killer-cell count increased significantly and stayed higher in non-relapsing patients than in relapsing patients, while receptor expression and functional properties remained unchanged. Altogether, our results suggest that natural killer cells may play a role in controlling leukemia-initiating cells at the origin of relapse after imatinib cessation, provided that these cells are numerous enough to compensate for their functional defects. Further research will decipher mechanisms underlying functional differences between natural killer cells from patients and healthy individuals and evaluate the potential interest of immunostimulatory approaches in tyrosine kinase inhibitor discontinuation strategies. (ClinicalTrial.gov Identifier NCT00478985).


Assuntos
Mesilato de Imatinib/uso terapêutico , Células Matadoras Naturais/citologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Contagem de Células , Intervalo Livre de Doença , Humanos , Interferon gama/análise , Células Matadoras Naturais/imunologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/imunologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/mortalidade , Inibidores de Proteínas Quinases/uso terapêutico , Receptores de Células Matadoras Naturais/análise , Recidiva
17.
J Immunol ; 195(6): 2580-90, 2015 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-26246143

RESUMO

Acute myeloid leukemia (AML) is a heterogeneous group of malignancies that may be sensitive to the NK cell antitumor response. However, NK cells are frequently defective in AML. In this study, we found in an exploratory cohort (n = 46) that NK cell status at diagnosis of AML separated patients in two groups with a different clinical outcome. Patients with a deficient NK cell profile, including reduced expression of some activating NK receptors (e.g., DNAX accessory molecule-1, NKp46, and NKG2D) and decreased IFN-γ production, had a significantly higher risk of relapse (p = 0.03) independently of cytogenetic classification in multivariate analysis. Patients with defective NK cells showed a profound gene expression decrease in AML blasts for cytokine and chemokine signaling (e.g., IL15, IFNGR1, IFNGR2, and CXCR4), Ag processing (e.g., HLA-DRA, HLA-DRB1, and CD74) and adhesion molecule pathways (e.g., PVR and ICAM1). A set of 388 leukemic classifier genes defined in the exploratory cohort was independently validated in a multicentric cohort of 194 AML patients. In total, these data evidenced the interplay between NK cells and AML blasts at diagnosis allowing an immune-based stratification of AML patients independently of clinical classifications.


Assuntos
Citotoxicidade Imunológica/imunologia , Células Matadoras Naturais/imunologia , Leucemia Mieloide Aguda/imunologia , Receptores de Células Matadoras Naturais/metabolismo , Evasão Tumoral/imunologia , Adulto , Idoso , Antígenos CD/imunologia , Moléculas de Adesão Celular/imunologia , Feminino , Cadeias alfa de HLA-DR/imunologia , Cadeias HLA-DRB1/imunologia , Humanos , Interferon gama/biossíntese , Interleucina-15/biossíntese , Leucemia Mieloide Aguda/diagnóstico , Masculino , Pessoa de Meia-Idade , Receptores CXCR4/biossíntese , Receptores de Interferon/biossíntese , Sialiltransferases/imunologia , Evasão Tumoral/genética , Adulto Jovem , Receptor de Interferon gama
18.
Blood ; 124(15): 2459-62, 2014 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-25185266

RESUMO

Using B-cell rearrangement excision circle measurements, we analyzed B-cell reconstitution in a cohort of 243 patients who underwent allogeneic stem cell transplantation. Acute and chronic graft-versus-host disease (aGVHD and cGVHD, respectively) transiently increased B-cell replication but decreased overall B-cell neogenesis with a clear difference in terms of kinetics. Moreover, the impact of aGVHD in the absence of cGVHD was transient, recovering at month 6 similar values as in patients who did not suffer from GVHD. Conversely, impact of cGVHD at month 12 in multivariate analysis was independent of the previous aGVHD effect on B-cell output. Finally, we showed in patients affected with cGVHD a higher B-cell division rate that correlates with an elevated BAFF/CD19(+) B-cell ratio, supporting a B-cell hyperactivation state in vivo.


Assuntos
Linfócitos B/imunologia , Linfócitos B/patologia , Divisão Celular , Doença Enxerto-Hospedeiro/imunologia , Doença Aguda , Adulto , Fator Ativador de Células B/sangue , Proliferação de Células , Doença Crônica , Doença Enxerto-Hospedeiro/sangue , Transplante de Células-Tronco Hematopoéticas , Humanos , Transplante Homólogo
19.
Eur J Immunol ; 44(10): 3068-80, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25041786

RESUMO

Acute myeloid leukemia (AML) cells are killed by allogeneic NK cells. However, autologous NK cells from AML patients express decreased levels of activating receptors, and show reduced cytotoxicity. Here, we investigated how interactions between NK and AML cells might cause loss of NK-cell activity in patients. Our results show that AML cell lines and primary blasts alter the NK-cell phenotype, reducing their cytotoxic potential upon prolonged contact. Downregulation of NK-cell-activating receptors was contact-dependent and correlated with conjugate formation. Time-lapse imaging of HL60 AML cell line and NK-cell interactions showed a high proportion of noncytolytic contacts. Studies of NK-cell immunological synapses revealed a defect in lytic synapse formation. Namely, despite correct F-actin and LFA-1 recruitment, polarization of lytic granules toward primary blasts or AML cell lines was reduced. The NK-AML cell line synapses showed impairment of CD3ζ recruitment. Attempts to correct these synapse defects by cytokine stimulation of NK cells improved conjugate formation, but not granule polarization. Pretreatment of AML cell lines with the immunomodulating molecule lenalidomide significantly enhanced granule polarization. We speculate that combining immunomodulatory drugs and cytokines could increase AML cell sensitivity to autologous NK cells and reinforce the activity of allogeneic NK cells in adoptive immunotherapy.


Assuntos
Citotoxicidade Imunológica/imunologia , Sinapses Imunológicas/imunologia , Células Matadoras Naturais/imunologia , Leucemia Mieloide Aguda/imunologia , Linhagem Celular Tumoral , Citometria de Fluxo , Humanos , Microscopia de Fluorescência , Imagem com Lapso de Tempo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA