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1.
J Immunol Methods ; 525: 113603, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38147898

RESUMO

CAR-T cells are T cells expressing a chimeric antigen receptor (CAR) rendering them capable of killing tumor cells after recognition of a target antigen. CD19 CAR-T cells have revolutionized the treatment of hematological malignancies. Their function is typically assessed by cytotoxicity assays using human allogeneic cell lines expressing the target antigen CD19 such as Nalm-6. However, an alloreactive reaction is observed with these cells, leading to a CD19-independent killing. To address this issue, we developed a fluorescence microscopy-based potency assay using murine target cells to provide an optimized cytotoxicity assay with enhanced specificity towards CD19. Murine NIH/3T3 (3T3) fibroblast-derived cell line and EL4 T-cell lymphoma-derived cell line were used as targets (no xenoreactivity was observed after coculture with human T cells). 3T3 and EL4 cells were engineered to express eGFP (enhanced Green Fluorescent Protein) and CD19 or CD22 using retroviral vectors. CD19 CAR-T cells and non-transduced (NT) control T cells were produced from several donors. After 4 h or 24 h, alloreactive cytotoxicity against CD19+ Nalm-6-GFP cells and CD19- Jurkat-GFP cells was observed with NT or CAR-T cells. In the same conditions, CAR-T but not NT cells specifically killed CD19+ but not CD19- 3T3-GFP or EL4-GFP cells. Both microscope- and flow cytometry-based assays revealed as sensitive as impedance-based assay. Using flow cytometry, we could further determine that CAR-T cells had mostly a stem cell-like memory phenotype after contact with EL4 target cells. Therefore, CD19+ 3T3-GFP or EL4-GFP cells and fluorescence microscopy- or flow cytometry-based assays provide convenient, sensitive and specific tools to evaluate CAR-T cell function with no alloreactivity.


Assuntos
Receptores de Antígenos Quiméricos , Camundongos , Animais , Humanos , Receptores de Antígenos Quiméricos/genética , Imunoterapia Adotiva , Testes Imunológicos , Ativação Linfocitária , Antígenos CD19/genética
2.
Cell Death Dis ; 14(5): 305, 2023 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-37142568

RESUMO

Autologous T cells engineered to express a chimeric antigen receptor (CAR) specific for CD19 are approved for the treatment of various CD19+ hematological malignancies. While CAR T cells induce objective responses in a majority of patients, relapse frequently occurs upon loss of CD19 expression by neoplastic cells. Radiation therapy (RT) has been successfully employed to circumvent the loss of CAR targets in preclinical models of pancreatic cancer. At least in part, this reflects the ability of RT to elicit death receptor (DR) expression by malignant cells, enabling at least some degree of CAR-independent tumor killing. In a human model of CD19+ acute lymphoblastic leukemia (ALL), we also observed DR upregulation by RT, both in vitro and in vivo. Moreover, low-dose total body irradiation (LD-TBI) delivered to ALL-bearing mice prior to CAR T cell infusion considerably extended the overall survival benefit afforded by CAR T cells alone. Such an improved therapeutic activity was accompanied by a superior expansion of CAR T cells in vivo. These data encourage the initiation of clinical trials combining LD-TBI with CAR T cells in patients with hematological malignancies.


Assuntos
Neoplasias Hematológicas , Leucemia-Linfoma Linfoblástico de Células Precursoras , Receptores de Antígenos Quiméricos , Humanos , Camundongos , Animais , Linfócitos T , Receptores de Antígenos de Linfócitos T , Leucemia-Linfoma Linfoblástico de Células Precursoras/radioterapia , Imunoterapia Adotiva
3.
Front Cardiovasc Med ; 10: 1132503, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37020516

RESUMO

CD19-specific chimeric antigen receptor T (CAR-T) cell therapy has recently been shown to improve the prognosis of refractory diffuse large B-cell lymphoma (DLBCL). However, CAR-T cells may induce numerous adverse events, in particular cytokine release syndrome (CRS) which is frequently associated with cardiovascular manifestations. Among the latter, acute pericardial effusion represents less than 1% of cases and cardiac tamponade has only been reported once. The management and outcome of these severe complications are not well established. We report here, a case of cardiac tamponade associated with CRS in a context of CAR-T cell therapy, which required urgent pericardiocentesis. Case summary: A 65-year-old man with refractory DLBCL was treated with CAR-T cell therapy. He had a history of dilated cardiomyopathy with preserved ejection fraction and transient atrial fibrillation. A pericardial localization of the lymphoma was observed on the second relapse. One day after CAR-T cell infusion the patient was diagnosed with grade 1 CRS. Due to hypotension, he was treated with tocilizumab and dexamethasone, and then transferred to intensive care unit (ICU). Echocardiography performed at ICU admission showed acute pericardial effusion with signs of right ventricular heart failure due to cardiac tamponade. It was decided to perform pericardiocentesis despite grade IV thrombocytopenia in a context of aplasia. Analysis of pericardial fluid showed a large number of lymphoma cells and 73% of CAR-T cells amongst lymphocytes, a level that was similar in blood. Hemodynamic status improved after pericardiocentesis, and no recurrence of pericardial effusion was observed. The presence of a high count of activated CAR-T cells in the pericardial fluid as well as the short interval between CAR-T cells injection and the symptoms appear as potential arguments for a direct action of CAR-T cells in the mechanism of this adverse event. The patient was discharged from ICU after two days and initially exhibited a good response to DLBCL treatment. Unfortunately, he died fifty days after starting CAR-T cell therapy due to a new DLBCL relapse. Conclusion: Patients with a pericardial localization of DLBCL should be assessed for a risk of cardiac tamponade if receiving CAR-T cell therapy and presenting CRS. In this case, cardiac tamponade seems directly related to CAR-T cell expansion. Pericardiocentesis should be considered as a feasible and effective treatment if the risk of bleeding is well controlled, in association with anti-IL6 and corticosteroids.

4.
Am J Kidney Dis ; 79(5): 760-764, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34461166

RESUMO

Post-transplant lymphoproliferative disorder is a growing complication of kidney transplantation and is associated with a poor prognosis. Anti-CD19 chimeric antigen receptor (CAR) T-cell therapy is an important new treatment option modifying the outcome of refractory hematological cancers. Here, we report the case of a 40-year-old kidney transplant recipient who developed a Burkitt-like lymphoma with 11q aberration 5 years after transplantation. After 3 unsuccessful lines of chemotherapy, it was decided to treat the patient with anti-CD19 CAR T cells as a salvage therapy. Three months after CAR T-cell infusion, she experienced a grade IIB T cell-mediated rejection with severe tubulitis (T3), slight interstitial inflammation (I1), and severe intimal arteritis (V2) with blood suffusion. Among T cells infiltrating the graft, some of them expressed the anti-CD19 CAR. CAR T cells within the graft and in blood samples were also detected by droplet digital polymerase chain reaction. Function of the kidney transplant improved after corticosteroid treatment and remained stable. However, lymphoma progressed, with a massive pulmonary mass leading to the patient's death 10 months after CAR T-cell infusion.


Assuntos
Transplante de Rim , Receptores de Antígenos Quiméricos , Adulto , Antígenos CD19 , Feminino , Humanos , Imunoterapia Adotiva , Transplante de Rim/efeitos adversos , Complicações Pós-Operatórias , Linfócitos T
5.
Front Immunol ; 12: 674276, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34566953

RESUMO

Adoptive immunotherapy based on the transfer of anti-tumor cytotoxic T lymphocytes (CTLs) is a promising strategy to cure cancers. However, rapid expansion of numerous highly functional CTLs with long-lived features remains a challenge. Here, we constructed NIH/3T3 mouse fibroblast-based artificial antigen presenting cells (AAPCs) and precisely evaluated their ability to circumvent this difficulty. These AAPCs stably express the essential molecules involved in CTL activation in the HLA-A*0201 context and an immunogenic HLA-A*0201 restricted analogue peptide derived from MART-1, an auto-antigen overexpressed in melanoma. Using these AAPCs and pentamer-based magnetic bead-sorting, we defined, in a preclinical setting, the optimal conditions to expand pure MART-1-specific CTLs. Numerous highly purified MART-1-specific CTLs were rapidly obtained from healthy donors and melanoma patients. Both TCR repertoire and CDR3 sequence analyses revealed that MART-1-specific CTL responses were similar to those reported in the literature and obtained with autologous or allogeneic presenting cells. These MART-1-specific CTLs were highly cytotoxic against HLA-A*0201+ MART-1+ tumor cells. Moreover, they harbored a suitable phenotype for immunotherapy, with effector memory, central memory and, most importantly, stem cell-like memory T cell features. Notably, the cells harboring stem cell-like memory phenotype features were capable of self-renewal and of differentiation into potent effector anti-tumor T cells. These "off-the-shelf" AAPCs represent a unique tool to rapidly and easily expand large numbers of long-lived highly functional pure specific CTLs with stem cell-like memory T cell properties, for the development of efficient adoptive immunotherapy strategies against cancers.


Assuntos
Células Apresentadoras de Antígenos/imunologia , Técnicas de Cultura de Células/métodos , Imunoterapia Adotiva/métodos , Melanoma , Linfócitos T Citotóxicos/imunologia , Animais , Humanos , Memória Imunológica/imunologia , Ativação Linfocitária/imunologia , Antígeno MART-1/imunologia , Camundongos , Células NIH 3T3
6.
Bull Cancer ; 108(12S): S53-S64, 2021 Dec.
Artigo em Francês | MEDLINE | ID: mdl-34253335

RESUMO

CAR-T cells represent a new anti-tumor immunotherapy which has shown its clinical efficacy in B-cell malignancies. The results of clinical trials carried out in this context have shown that certain immunological characteristics of patients before (at the time of apheresis) and after the administration of the treatment, or of the CAR-T cells themselves, are correlated with the response to the treatment or to its toxicity. However, to date, there are no recommendations on the immunological monitoring of patients treated in real life. The objectives of this workshop were to determine, based on data from the literature and the experience of the centers, the immunological analyses to be carried out in patients treated with CAR-T cells. The recommendations relate to the characterization of the patient's immune cells at the time of apheresis, the characterization of the injected CAR-T cells, as well as the monitoring of the CAR-T cells and other parameters of immune reconstitution in the patient after administration of the treatment. Harmonization of practices will allow clinical-biological correlation studies to be carried out in patients treated in real life with the aim of identifying factors predictive of response and toxicity. Such data could have a major medico-economic impact by making it possible to identify the patients who will optimally benefit from these expensive treatments.


Assuntos
Neoplasias Hematológicas/imunologia , Neoplasias Hematológicas/terapia , Reconstituição Imune , Imunoterapia Adotiva , Monitorização Imunológica/normas , Infecções Bacterianas/etiologia , Remoção de Componentes Sanguíneos , Síndrome da Liberação de Citocina/imunologia , Citometria de Fluxo , Humanos , Imunidade Celular , Imunoterapia Adotiva/efeitos adversos , Leucemia Linfocítica Crônica de Células B/imunologia , Leucemia Linfocítica Crônica de Células B/terapia , Depleção Linfocítica , Linfoma Difuso de Grandes Células B/imunologia , Linfoma Difuso de Grandes Células B/terapia , Monitorização Imunológica/métodos , Mieloma Múltiplo/imunologia , Mieloma Múltiplo/terapia , Micoses/etiologia , Síndromes Neurotóxicas/imunologia , Reação em Cadeia da Polimerase , Leucemia-Linfoma Linfoblástico de Células Precursoras/imunologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Recidiva , Sociedades Médicas , Linfócitos T/efeitos dos fármacos , Linfócitos T/transplante , Viroses/etiologia
7.
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
8.
Front Immunol ; 10: 1081, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31156634

RESUMO

CD4+ T cells differentiate into various T helper subsets characterized by distinct cytokine secreting profiles that confer them effector functions adapted to a variety of infectious or endogenous threats. Regulatory CD4+ T cells are another specialized subset that plays a fundamental role in the maintenance of immune tolerance to self-antigens. Manipulating effector or regulatory CD4+ T cells responses is a promising immunotherapy strategy for, respectively, chronical viral infections and cancer, or severe autoimmune diseases and transplantation. Adoptive cell therapy (ACT) is an emerging approach that necessitates defining robust and efficient methods for the in vitro expansion of antigen-specific T cells then infused into patients. To address this challenge, artificial antigen presenting cells (AAPCs) have been developed. They constitute a reliable and easily usable platform to stimulate and amplify antigen-specific CD4+ T cells. Here, we review the recent advances in understanding the functions of CD4+ T cells in immunity and in immune tolerance, and their use for ACT. We also describe the characteristics of different AAPC models and the way to improve their stimulating functions. Finally, we discuss the potential interest of these AAPCs, both as fundamental tools to decipher CD4+ T cell responses and as reagents to generate clinical grade antigen-specific CD4+ T cells for immunotherapy.


Assuntos
Células Apresentadoras de Antígenos/imunologia , Linfócitos T CD4-Positivos/imunologia , Vacinas Anticâncer/imunologia , Imunoterapia Adotiva/métodos , Linfócitos T Reguladores/imunologia , Apresentação de Antígeno , Linfócitos T CD4-Positivos/transplante , Proliferação de Células , Antígenos HLA/metabolismo , Antígenos de Histocompatibilidade Classe II/metabolismo , Humanos , Linfócitos T Reguladores/transplante
9.
Oncoimmunology ; 8(4): e1560919, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30906653

RESUMO

There is now a consensus that efficient peptide vaccination against cancer requires that peptides should (i) be exclusively presented by professional APC and (ii) stimulate both CD4 and CD8-specific T cell responses. To this aim, in recent trials, patients were vaccinated with pools of synthetic long peptides (SLP) (15-30 aa long) composed of a potential class I epitope(s) elongated at both ends with native antigen sequences to also provide a potential class II epitope(s). Using MELOE-1 as a model antigen, we present an alternative strategy consisting in linking selected class I and class II epitopes with an artificial cathepsin-sensitive linker to improve epitope processing and presentation by DC. We provide evidence that some linker sequences used in our artificial SLPs (aSLPs) could increase up to 100-fold the cross-presentation of class I epitopes to CD8-specific T cell clones when compared to cross-presentation of the corresponding native long peptide. Presentation of class II epitopes were only slightly increased. We confirmed this increased cross-presentation after in vitro stimulation of PBMC from healthy donors with aSLP and assessment of CD8-specific responses and also in vivo following aSLP vaccination of HLA*A0201/HLA-DRB0101 transgenic mice. Finally, we provide some evidence that vaccination with aSLP could inhibit the growth of transplanted tumors in mice. Our data thus support the use of such aSLPs in future cancer vaccination trials to improve anti-tumor CD8 T cell responses and therapeutic efficacy.

10.
Haematologica ; 102(11): 1833-1841, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28751567

RESUMO

Acquired thrombotic thrombocytopenic purpura is a rare and severe disease characterized by auto-antibodies directed against "A Disintegrin And Metalloproteinase with Thrombospondin type 1 repeats, 13th member" (ADAMTS13), a plasma protein involved in hemostasis. Involvement of CD4+ T cells in the pathogenesis of the disease is suggested by the IgG isotype of the antibodies. However, the nature of the CD4+ T-cell epitopes remains poorly characterized. Here, we determined the HLA-DR-restricted CD4+ T-cell epitopes of ADAMTS13. Candidate T-cell epitopes were predicted in silico and binding affinities were confirmed in competitive enzyme-linked immunosorbent assays. ADAMTS13-reactive CD4+ T-cell hybridomas were generated following immunization of HLA-DR1 transgenic mice (Sure-L1 strain) and used to screen the candidate epitopes. We identified the ADAMTS131239-1253 peptide as the single immunodominant HLA-DR1-restricted CD4+ T-cell epitope. This peptide is located in the CUB2 domain of ADAMTS13. It was processed by dendritic cells, stimulated CD4+ T cells from Sure-L1 mice and was recognized by CD4+ T cells from an HLA-DR1-positive patient with acute thrombotic thrombocytopenic purpura. Interestingly, the ADAMTS131239-1253 peptide demonstrated promiscuity towards HLA-DR11 and HLA-DR15. Our work paves the way towards the characterization of the ADAMTS13-specific CD4+ T-cell response in patients with thrombotic thrombocytopenic purpura using ADAMTS131239-1253-loaded HLA-DR tetramers.


Assuntos
Proteína ADAMTS13/imunologia , Linfócitos T CD4-Positivos/imunologia , Epitopos de Linfócito T/imunologia , Antígeno HLA-DR1/imunologia , Epitopos Imunodominantes/imunologia , Fragmentos de Peptídeos/imunologia , Proteína ADAMTS13/química , Alelos , Sequência de Aminoácidos , Animais , Células Apresentadoras de Antígenos/imunologia , Células Apresentadoras de Antígenos/metabolismo , Linfócitos T CD4-Positivos/metabolismo , Epitopos de Linfócito T/química , Antígeno HLA-DR1/química , Antígeno HLA-DR1/metabolismo , Humanos , Imunização , Epitopos Imunodominantes/química , Imunoglobulina G/imunologia , Camundongos , Camundongos Transgênicos , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/metabolismo , Ligação Proteica/imunologia , Púrpura Trombocitopênica Trombótica/genética , Púrpura Trombocitopênica Trombótica/imunologia , Púrpura Trombocitopênica Trombótica/metabolismo
11.
Leuk Res ; 60: 53-57, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28651105

RESUMO

We examined the consequences of 3-deazaneplanocin A (DZNep) on HACE1 expression in human Burkitt- Lymphoma-derived cells to investigate fundamental molecular mechanisms that control its expression. We treated the human Burkitt- Lymphoma-derived cells lines Ramos and Raji with DZNep and examined HACE1 mRNA expression by RT-PCR. We also studied the effect of DZNep on the methylation of lysine 9 and 27 of histone 3 (H3K27me3 and H3K9me2) associated with the CpG88 and CpG177 islands of the HACE1 promoters by chromatin immunoprecipitation and quantitative PCR. CpG88 (hypomethylated) of the HACE1 promoter was enriched for histone marks H3K27me3 and H3K9me2 whereas CpG177 (hypermethylated) was only enriched for H3K9me2. DZNep treatment increased HACE1 gene expression which was further increased by the addition of trichostatine A (TSA), a promising therapeutic compound for the treatment of human B-Lymphoma. Histone methylation (both H3K9me2 and H3K27me3) of the HACE1 promoter concomitantly decreased. Our experiments suggest that HACE1 can be downregulated by methylation of its promoter region chromatin (H3K27me3 and H3K9me2), making HACE1 a potential target for DZNep combined with TSA. These results highlight the heterogeneity of HACE1 regulation in B-lymphoma and suggest that successful drug-induced restoration of epigenetically silenced tumor suppressor genes will require accurate characterization of cell type- and locus-specific gene silencing mechanisms.


Assuntos
Linfoma de Burkitt/patologia , Epigênese Genética , Ubiquitina-Proteína Ligases/genética , Adenosina/análogos & derivados , Adenosina/farmacologia , Linfoma de Burkitt/tratamento farmacológico , Linhagem Celular Tumoral , Ilhas de CpG , Metilação de DNA/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica , Histonas/metabolismo , Humanos , Ácidos Hidroxâmicos/farmacologia , Regiões Promotoras Genéticas , RNA Mensageiro/análise , Ubiquitina-Proteína Ligases/efeitos dos fármacos
12.
Oncotarget ; 8(30): 48959-48971, 2017 07 25.
Artigo em Inglês | MEDLINE | ID: mdl-28430664

RESUMO

HLA-A*0201/DRB1*0101 transgenic mice (A2/DR1 mice) have been developed to study the immunogenicity of tumor antigen-derived T cell epitopes. To extend the use and application of this mouse model in the field of antitumor immunotherapy, we described a tumor cell line generated from a naturally occurring tumor in A2/DR1 mouse named SARC-L1. Histological and genes signature analysis supported the sarcoma origin of this cell line. While SARC-L1 tumor cells lack HLA-DRB1*0101 expression, a very low expression of HLA-A*0201 molecules was found on these cells. Furthermore they also weakly but constitutively expressed the programmed death-ligand 1 (PD-L1). Interestingly both HLA-A*0201 and PD-L1 expressions can be increased on SARC-L1 after IFN-γ exposure in vitro. We also obtained two genetically modified cell lines highly expressing either HLA-A*0201 or both HLA-A*0201/ HLA-DRB1*0101 molecules referred as SARC-A2 and SARC-A2DR1 respectively. All the SARC-L1-derived cell lines induced aggressive subcutaneous tumors in A2DR1 mice in vivo. The analysis of SARC-L1 tumor microenvironment revealed a strong infiltration by T cells expressing inhibitory receptors such as PD-1 and TIM-3. Finally, we found that SARC-L1 is sensitive to several drugs commonly used to treat sarcoma and also susceptible to anti-PD-L1 monoclonal antibody therapy in vivo. Collectively, we described a novel syngeneic tumor model A2/DR1 mice that could be used as preclinical tool for the evaluation of antitumor immunotherapies.


Assuntos
Antígeno B7-H1/genética , Antígeno HLA-A2/genética , Cadeias HLA-DRB1/genética , Neoplasias/genética , Animais , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Apoptose/genética , Apoptose/imunologia , Antígeno B7-H1/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Modelos Animais de Doenças , Feminino , Expressão Gênica , Perfilação da Expressão Gênica , Antígeno HLA-A2/imunologia , Cadeias HLA-DRB1/imunologia , Humanos , Linfócitos do Interstício Tumoral/efeitos dos fármacos , Linfócitos do Interstício Tumoral/imunologia , Linfócitos do Interstício Tumoral/metabolismo , Masculino , Camundongos , Camundongos Transgênicos , Neoplasias/imunologia , Neoplasias/metabolismo , Neoplasias/patologia , Sarcoma/genética , Sarcoma/metabolismo , Sarcoma/patologia
13.
Oncoimmunology ; 5(5): e1115943, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27467916

RESUMO

Microsatellite unstable colorectal cancers (CRC) express frameshift mutation-derived tumor-specific neoantigens. We recently showed that: (i) frameshift mutations were correlated with tumor-infiltrating CD8(+) T cell density, (ii) neoantigen-specific cytotoxic T cells could be obtained in patients whose tumors harbored these mutations, underlining the interest of developing personalized immunotherapy strategies in these cancers.

14.
Leuk Res ; 45: 90-100, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27107267

RESUMO

HECT domain and ankyrin repeat containing E3 ubiquitin protein ligase 1, HACE1, located on chromosome 6q, encodes an E3 ubiquitin ligase and is downregulated in many human tumors. Here, we report HACE1 as a candidate tumor suppressor gene down-regulated by a combination of deletion and epigenetic mechanisms. HACE1 deletions were observed in 40% of B-cell lymphoma tumors. Hypermethylation of the HACE1 promoter CpG177 island was found in 60% (68/111) of cases and in all tested B-cell lymphoma lines. Using HDAC inhibitors, we observed predominantly inactive chromatin conformation (methylated H3 histones H3K9me2) in HACE1 gene promoter region. We demonstrated in Ramos and Raji cells that down-regulation of HACE1 expression was associated with a significant decrease in apoptosis and an accumulation of cells in the S and G2/M phases. Our experiments indicate that HACE1 can act as a haploinsufficient tumor suppressor gene in most B-cell lymphomas and can be downregulated by deacetylation of its promoter region chromatin, which makes HACE1 a potential target for HDAC inhibitors.


Assuntos
Regulação para Baixo/genética , Epigênese Genética , Deleção de Genes , Linfoma de Células B/genética , Ubiquitina-Proteína Ligases/fisiologia , Acetilação , Apoptose , Pontos de Checagem do Ciclo Celular , Linhagem Celular Tumoral , Metilação de DNA , Regulação Neoplásica da Expressão Gênica , Genes Supressores de Tumor , Inibidores de Histona Desacetilases/farmacologia , Humanos , Regiões Promotoras Genéticas , Ubiquitina-Proteína Ligases/genética
15.
Immunity ; 44(3): 698-711, 2016 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-26982367

RESUMO

Microsatellite instability in colorectal cancer predicts favorable outcomes. However, the mechanistic relationship between microsatellite instability, tumor-infiltrating immune cells, Immunoscore, and their impact on patient survival remains to be elucidated. We found significant differences in mutational patterns, chromosomal instability, and gene expression that correlated with patient microsatellite instability status. A prominent immune gene expression was observed in microsatellite-instable (MSI) tumors, as well as in a subgroup of microsatellite-stable (MSS) tumors. MSI tumors had increased frameshift mutations, showed genetic evidence of immunoediting, had higher densities of Th1, effector-memory T cells, in situ proliferating T cells, and inhibitory PD1-PDL1 cells, had high Immunoscores, and were infiltrated with mutation-specific cytotoxic T cells. Multivariate analysis revealed that Immunoscore was superior to microsatellite instability in predicting patients' disease-specific recurrence and survival. These findings indicate that assessment of the immune status via Immunoscore provides a potent indicator of tumor recurrence beyond microsatellite-instability staging that could be an important guide for immunotherapy strategies.


Assuntos
Neoplasias Colorretais/diagnóstico , Imunoensaio/métodos , Patologia Molecular/métodos , Subpopulações de Linfócitos T/imunologia , Células Th1/imunologia , Idoso , Idoso de 80 Anos ou mais , Células Cultivadas , Neoplasias Colorretais/mortalidade , Testes Imunológicos de Citotoxicidade , Análise Mutacional de DNA , Feminino , Mutação da Fase de Leitura/genética , Humanos , Memória Imunológica , Masculino , Instabilidade de Microssatélites , Repetições de Microssatélites , Valor Preditivo dos Testes , Prognóstico , Análise de Sobrevida , Transcriptoma
16.
Immunol Cell Biol ; 94(7): 662-72, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-26924643

RESUMO

Owing to their multiple immune functions, CD4(+) T cells are of major interest for immunotherapy in chronic viral infections and cancer, as well as for severe autoimmune diseases and transplantation. Therefore, standardized methods allowing rapid generation of a large number of CD4(+) T cells for adoptive immunotherapy are still awaited. We constructed stable artificial antigen-presenting cells (AAPCs) derived from mouse fibroblasts. They were genetically modified to express human leukocyte antigen (HLA)-DR molecules and the human accessory molecules B7.1, Intercellular adhesion molecule-1 (ICAM-1) and lymphocyte function-associated antigen-3 (LFA-3). AAPCs expressing HLA-DR1, HLA-DR15 or HLA-DR51 molecules and loaded with peptides derived from influenza hemagglutinin (HA), myelin basic protein (MBP) or factor VIII, respectively, activated specific CD4(+) T-cell clones more effectively than Epstein-Barr virus (EBV)-transformed B cells. We also showed that AAPCs were able to take up and process whole Ag proteins, and present epitopes to specific T cells. In primary cultures, AAPCs loaded with HA peptide allowed generation of specific Th1 lymphocytes from healthy donors as demonstrated by tetramer and intracellular cytokine staining. Although AAPCs were less effective than autologous peripheral blood mononuclear cells (PBMCs) to stimulate CD4(+) T cells in primary culture, AAPCs were more potent to reactivate and expand memory Th1 cells in a strictly Ag-dependent manner. As the availability of autologous APCs is limited, the AAPC system represents a stable and reliable tool to achieve clinically relevant numbers of CD4(+) T cells for adoptive immunotherapy. For fundamental research in immunology, AAPCs are also useful to decipher mechanisms involved in the development of human CD4 T-cell responses.


Assuntos
Células Apresentadoras de Antígenos/imunologia , Células Artificiais/imunologia , Linfócitos T CD4-Positivos/imunologia , Antígenos de Histocompatibilidade Classe II/metabolismo , Memória Imunológica , Animais , Apresentação de Antígeno/imunologia , Linfócitos T CD4-Positivos/citologia , Proliferação de Células , Epitopos/imunologia , Humanos , Ativação Linfocitária/imunologia , Camundongos , Células NIH 3T3 , Peptídeos/metabolismo , Fenótipo , Doadores de Tecidos
17.
Cancer Res ; 75(17): 3446-55, 2015 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-26060019

RESUMO

Colorectal cancers with microsatellite instability (MSI) represent 15% of all colorectal cancers, including Lynch syndrome as the most frequent hereditary form of this disease. Notably, MSI colorectal cancers have a higher density of tumor-infiltrating lymphocytes (TIL) than other colorectal cancers. This feature is thought to reflect the accumulation of frameshift mutations in sequences that are repeated within gene coding regions, thereby leading to the synthesis of neoantigens recognized by CD8(+) T cells. However, there has yet to be a clear link established between CD8(+) TIL density and frameshift mutations in colorectal cancer. In this study, we examined this link in 103 MSI colorectal cancers from two independent cohorts where frameshift mutations in 19 genes were analyzed and CD3(+), CD8(+), and FOXP3(+) TIL densities were quantitated. We found that CD8(+) TIL density correlated positively with the total number of frameshift mutations. TIL densities increased when frameshift mutations were present within the ASTE1, HNF1A, or TCF7L2 genes, increasing even further when at least one of these frameshift mutations was present in all tumor cells. Through in vitro assays using engineered antigen-presenting cells, we were able to stimulate peripheral cytotoxic T cells obtained from colorectal cancer patients with peptides derived from frameshift mutations found in their tumors. Taken together, our results highlight the importance of a CD8(+) T cell immune response against MSI colorectal cancer-specific neoantigens, establishing a preclinical rationale to target them as a personalized cellular immunotherapy strategy, an especially appealing goal for patients with Lynch syndrome.


Assuntos
Neoplasias Colorretais Hereditárias sem Polipose/imunologia , Neoplasias Colorretais/imunologia , Linfócitos do Interstício Tumoral/imunologia , Instabilidade de Microssatélites , Células Apresentadoras de Antígenos/imunologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/patologia , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Neoplasias Colorretais Hereditárias sem Polipose/genética , Neoplasias Colorretais Hereditárias sem Polipose/patologia , Feminino , Fatores de Transcrição Forkhead/genética , Mutação da Fase de Leitura/genética , Humanos , Imunoterapia , Linfócitos do Interstício Tumoral/patologia , Masculino , Medicina de Precisão
18.
Immun Inflamm Dis ; 3(1): 1-13, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25866635

RESUMO

Adoptive transfer of in vitro activated and expanded antigen-specific cytotoxic T lymphocytes (CTLs) is a promising therapeutic strategy for infectious diseases and cancers. Obtaining in vitro a sufficient amount of highly specific cytotoxic cells and capable of retaining cytotoxic activity in vivo remains problematic. We studied the role of Toll-Like Receptor-8 (TLR8) engagement on peripheral CTLs activated with melanoma antigen MART-1-expressing artificial antigen-presenting cells (AAPCs). After a 3-week co-culture, 3-27% of specific CTLs were consistently obtained. CTLs expressed TLR8 in the intracellular compartment and at the cell surface. Specific CTLs activated with a TLR8 agonist (CL075) 24 h before the end of the culture displayed neither any change in their production levels of molecules involved in cytotoxicity (IFN-γ, Granzyme B, and TNF-α) nor major significant change in their cell surface phenotype. However, these TLR8-stimulated lymphocytes displayed increased cytotoxic activity against specific peptide-pulsed target cells related to an increase in specific anti-melanoma CTL functional avidity. TLR8 engagement on CTLs could, therefore, be useful in different immunotherapy strategies.

19.
Bull Cancer ; 100(9): 871-85, 2013 Sep.
Artigo em Francês | MEDLINE | ID: mdl-23917703

RESUMO

Recent studies have underlined the close link between immune response and prognosis of patients with colorectal cancer (CRC). Immune response understanding combined with biotechnology progress of the last years has allowed development of immunotherapy strategies in CRC. Immunotherapy strategies are divided in "active" or "passive" strategies (patients immune system stimulation or not) and considering the activation of antigen specific immune response or not. These immunotherapy strategies are well tolerated and induced cellular and humoral response correlated with clinical response. Many monoclonal antibodies targeting signalisation pathways or angiogenic growth factors have demonstrated their efficacy in CRC. Multiple vaccine strategies, using different tumour associated antigens, have demonstrated a biological efficacy but with poor clinical results. Results are more promising in adjuvant setting but need to be confirmed by randomized trials. Adoptive immunotherapy with transfer of tumour associated antigen specific T cell is probably the most promising strategy. Actually, except monoclonal antibodies, immunotherapy is not used in clinical practice in CRC due to the lack of results and absence of standardisation.


Assuntos
Neoplasias Colorretais/terapia , Imunoterapia/métodos , Adjuvantes Imunológicos/uso terapêutico , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/uso terapêutico , Antígenos de Neoplasias/imunologia , Antígenos de Neoplasias/uso terapêutico , Antineoplásicos/uso terapêutico , Vacinas Anticâncer/imunologia , Vacinas Anticâncer/uso terapêutico , Neoplasias Colorretais/imunologia , Humanos , Imunidade Celular , Imunoterapia Adotiva/métodos , Prognóstico , Linfócitos T/imunologia , Linfócitos T/transplante
20.
PLoS One ; 8(4): e61001, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23613769

RESUMO

BACKGROUND: Colorectal cancers (CRCs) with microsatellite instability (MSI) are associated with a good prognosis and a high density of tumor-infiltrating lymphocytes (TILs). We have undertaken to determine the link between TIL densities and MSI CRC histologic features. PATIENTS AND METHODS: Using tissue microarrays, T-cell sub-population infiltration, including T cells (CD3), cytotoxic T cells (CD8) and regulatory T cells (FoxP3) were studied in 86 MSI CRCs. We separately analyzed TILs of the stromal and epithelial compartments in the tumor center, the tumoral invasion margin and associated normal tissue. RESULTS: For FoxP3+ TIL density in the tumor center stromal compartment, we found a strong negative correlation with T4 stage (p = 0.01), node invasion (p<0.001) and VELIPI (vascular emboli, lymphatic invasion and perinervous invasion) criteria (p = 0.002). CONCLUSION: The strong correlation between regulatory T cell density and the absence of VELIPI criteria suggests that this sub-group of T cells is preferentially associated with less invasive tumors.


Assuntos
Neoplasias Colorretais/imunologia , Neoplasias Colorretais/patologia , Instabilidade de Microssatélites , Linfócitos T Reguladores/imunologia , Idoso , Contagem de Células , Neoplasias Colorretais/genética , Feminino , Humanos , Masculino , Linfócitos T Citotóxicos/citologia , Linfócitos T Citotóxicos/imunologia , Linfócitos T Reguladores/citologia
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