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1.
Adv Exp Med Biol ; 1172: 21-62, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31628650

RESUMO

Molecules encoded by the Major Histocompatibility Complex (MHC) bind self or foreign peptides and display these at the cell surface for recognition by receptors on T lymphocytes (designated T cell receptors-TCR) or on natural killer (NK) cells. These ligand/receptor interactions govern T cell and NK cell development as well as activation of T memory and effector cells. Such cells participate in immunological processes that regulate immunity to various pathogens, resistance and susceptibility to cancer, and autoimmunity. The past few decades have witnessed the accumulation of a huge knowledge base of the molecular structures of MHC molecules bound to numerous peptides, of TCRs with specificity for many different peptide/MHC (pMHC) complexes, of NK cell receptors (NKR), of MHC-like viral immunoevasins, and of pMHC/TCR and pMHC/NKR complexes. This chapter reviews the structural principles that govern peptide/MHC (pMHC), pMHC/TCR, and pMHC/NKR interactions, for both MHC class I (MHC-I) and MHC class II (MHC-II) molecules. In addition, we discuss the structures of several representative MHC-like molecules. These include host molecules that have distinct biological functions, as well as virus-encoded molecules that contribute to the evasion of the immune response.


Assuntos
Imunidade Adaptativa , Imunidade Inata , Complexo Principal de Histocompatibilidade , Receptores de Antígenos de Linfócitos T , Linfócitos T , Imunidade Adaptativa/imunologia , Animais , Humanos , Imunidade Inata/imunologia , Complexo Principal de Histocompatibilidade/imunologia , Receptores de Antígenos de Linfócitos T/química , Receptores de Antígenos de Linfócitos T/imunologia , Receptores de Células Matadoras Naturais/química , Receptores de Células Matadoras Naturais/imunologia , Linfócitos T/imunologia
2.
Cancer Immunol Immunother ; 68(10): 1701-1712, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31542797

RESUMO

Since the first bone marrow transplantation, adoptive T cell therapy (ACT) has developed over the last 80 years to a highly efficient and specific therapy for infections and cancer. Genetic engineering of T cells with antigen-specific receptors now provides the possibility of generating highly defined and efficacious T cell products. The high sensitivity of engineered T cells towards their targets, however, also bears the risk of severe off-target toxicities. Therefore, different safety strategies for engineered T cells have been developed that enable removal of the transferred cells in case of adverse events, control of T cell activity or improvement of target selectivity. Receptor avidity is a crucial component in the balance between safety and efficacy of T cell products. In clinical trials, T cells equipped with high avidity T cell receptor (TCR)/chimeric antigen receptor (CAR) have been mostly used so far because of their faster and better response to antigen recognition. However, over-activation can trigger T cell exhaustion/death as well as side effects due to excessive cytokine production. Low avidity T cells, on the other hand, are less susceptible to over-activation and could possess better selectivity in case of tumor antigens shared with healthy tissues, but complete tumor eradication may not be guaranteed. In this review we describe how 'optimal' TCR/CAR affinity can increase the safety/efficacy balance of engineered T cells, and discuss simultaneous or sequential infusion of high and low avidity receptors as further options for efficacious but safe T cell therapy.


Assuntos
Imunoterapia Adotiva/métodos , Receptores de Antígenos de Linfócitos T/imunologia , Receptores de Antígenos Quiméricos/imunologia , Linfócitos T/imunologia , Afinidade de Anticorpos , Engenharia Genética , Humanos , Imunoterapia Adotiva/efeitos adversos
3.
Adv Exp Med Biol ; 1143: 217-229, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31338822

RESUMO

Cancer immunotherapy has been shown to be an efficacious therapeutic approach in the treatment of cancers including hematopoietic malignancies. Induction of T cell cytotoxicity against tumors by adoptive cell therapies (ACT), cancer vaccines, gene therapies, and monoclonal antibody therapies has been intensively studied. In particular, immune checkpoint blockade and chimeric antigen receptor T (CAR-T) cell therapies are the recent clinical successes in cancer immunotherapy. This article introduces the main concepts and addresses the most relevant clinical modalities of cellular immunotherapies for hematological malignancies: antigen non-specific T cell therapy, genetically modified T cell receptor (TCR) T cell therapy, chimeric antigen receptor (CAR) T cell therapy, and CAR-T cell clinical trials in leukemia, lymphoma, and multiple myeloma. Clinical trials have shown encouraging results, but future studies may need to incorporate novel CAR constructs or targets with enhanced safety and efficacy to ensure long-term benefits.


Assuntos
Neoplasias Hematológicas , Imunoterapia Adotiva , Neoplasias Hematológicas/terapia , Humanos , Receptores de Antígenos de Linfócitos T/imunologia , Linfócitos T
4.
Mol Biol (Mosk) ; 53(3): 456-466, 2019.
Artigo em Russo | MEDLINE | ID: mdl-31184611

RESUMO

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the only curative therapy for hematopoietic malignancies. The graft-derived donor lymphocytes are capable of eliminating the residual recipient malignant cells in the course of allogeneic immune response, thus decreasing the chances of a relapse of the disease. Foreign peptides of the recipient presented by the MHC molecules are able to elicit the immune response immunologically. These polymorphic peptides are known as minor histocompatibility antigens (MiHAs). MiHAs occur due to the nonsynonymous single nucleotide polymorphisms in human genome. Transfusion of T cells specific to MiHAs presented predominantly in the cells of hematopoietic origin will allow the targeted elimination of residual malignant clones avoiding undesirable damage to healthy tissues. To induce the immune response, the donor must be homozygous by the MiHA allele and the recipient must either be homozygous or heterozygous by the alternative MiHA allele. The therapeutic mismatch occurs in 25% of cases under the optimal frequency of allelic variants. Minor antigen ACC-1Y originates from polymorphism in the BCL-2A1 gene; its immunogenic mismatch occurrence approaches the theoretical maximum. In addition, BCL2A1 is overexpressed in cells of various lymphomas. ACC-1Y is presented on allele HLA-A*24:02, which is relatively frequent in the Russian population. Combination of these factors makes the minor antigen ACC-1Y a promising target for immunotherapy. Transfusion of donor CD8^(+) lymphocytes modified with transgenic MiHA-specific TCR is one of the promising methods of posttransplant leukemia therapy and relapse prophylaxis. We obtained a sequence of high-affinity ACC-1Y-specific TCR after the antigen-specific expansion of T cells derived from a healthy ACC-IY^(-/-) donor. We cloned this sequence into the lentiviral vector and obtained the assembled viral particles. Further, we transduced the CD8^(+) lymphocyte culture and demonstrated its antigen-specific cytotoxic activity. It is suggested that CD8^(+) lymphocytes modified by the described method could be potentially transferred to recipients as a therapy against relapse after allo-HSCT.


Assuntos
Engenharia Celular , Transplante de Células-Tronco Hematopoéticas , Antígenos de Histocompatibilidade Menor/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Linfócitos T Citotóxicos/imunologia , Linfócitos T Citotóxicos/metabolismo , Aloenxertos , Neoplasias Hematológicas/genética , Neoplasias Hematológicas/imunologia , Neoplasias Hematológicas/terapia , Humanos , Antígenos de Histocompatibilidade Menor/genética , Receptores de Antígenos de Linfócitos T/genética , Federação Russa , Prevenção Secundária/métodos
5.
Mol Immunol ; 112: 274-282, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31226552

RESUMO

The viral peptides presentation by major histocompatibility complex class I (MHC I) molecules play a pivotal role in T-cell recognition and the subsequent virus clearance. This process is delicately adjusted by the variant residues of MHC I, especially the residues in the peptide binding groove (PBG). In a series of MHC I molecules, a salt bridge is formed above the N-terminus of the peptides. However, the potential impact of the salt bridge on peptide binding and T-cell receptor (TCR) recognition of MHC I, as well as the corresponding molecular basis, are still largely unknown. Herein, we determined the structures of HLA-B*4001 and H-2Kd in which two different types of salt bridges (Arg62-Glu163 or Arg66-Glu163) across the PBG were observed. Although the two salt bridges led to different conformation shifts of both the MHC I α helix and the peptides, binding of the peptides with the salt bridge residues was relatively conserved. Furthermore, through a series of in vitro and in vivo investigations, we found that MHC I mutations that disrupt the salt bridge alleviate peptide binding and can weaken the TCR recognition of MHC I-peptide complexes. Our study may provide key references for understanding MHC I-restricted peptide recognition by T-cells.


Assuntos
Apresentação do Antígeno/imunologia , Genes MHC Classe I/imunologia , Antígenos de Histocompatibilidade Classe I/imunologia , Peptídeos/imunologia , Ligação Proteica/imunologia , Linfócitos T/imunologia , Animais , Sítios de Ligação/imunologia , Feminino , Antígenos HLA-B/imunologia , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Conformação Proteica , Receptores de Antígenos de Linfócitos T/imunologia
6.
Mol Immunol ; 112: 312-321, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31229844

RESUMO

Precise glycosylation plays a crucial and distinctive role in thymic T cell development. The core fucosylation is dramatically up-regulated at the transition from CD4-CD8- (DN) to CD4+CD8+ (DP) in the thymic development. Ablation of core fucosylation in T cells did reduce the size of the thymus due to a significant loss of CD4+ SP, CD8+ SP and DP thymocytes in core fucosyltransferase (Fut8) knockout (Fut8-/-) mice. T cell receptors (TCRs) are heavily core fucosylated glycoproteins. Loss of core fucosylation of TCR contributed to the reduced phosphorylation of ZAP70 (pZAP70) in Fut8-/- DP cells was observed. Compare to the Fut8+/+OT-II DP thymocytes, pZAP70 was significantly reduced in Fut8-/- OT-II DP thymocytes with OVA323-339 stimulation. Also, the pZAP70 of Fut8+/+OT-I DP thymocytes with OVA257-264 stimulation was remarkably attenuated by treatment of the fucosidase. Upon anti-CD3/CD28 Abs stimulation, the increased apoptosis was found in Fut8-/- thymocytes compared with Fut8+/+ thymocytes. Moreover, the TCRhiCD69hi (post-positive selection thymocytes) was markedly depleted in the Fut8-/- thymus without any stimulation. The expression of CD5 was significantly down-regulated on the DP cells in the Fut8-/- thymus. Our results therefore demonstrate that ablation of core fucosylation results in the abnormal T cell development due to the attenuated signaling via TCR.


Assuntos
Fucose/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Transdução de Sinais/imunologia , Linfócitos T/imunologia , Animais , Antígenos CD/imunologia , Antígenos de Diferenciação de Linfócitos T/imunologia , Apoptose/imunologia , Antígenos CD5/imunologia , Diferenciação Celular/imunologia , Fucosiltransferases/imunologia , Glicosilação , Lectinas Tipo C/imunologia , Ativação Linfocitária/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Fosforilação/imunologia , Timócitos/imunologia , Proteína-Tirosina Quinase ZAP-70/imunologia
7.
Nat Commun ; 10(1): 2603, 2019 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-31197149

RESUMO

During thymic negative selection, autoreactive thymocytes carrying T cell receptor (TCR) with overtly strong affinity to self-MHC/self-peptide are removed by Bim-dependent apoptosis, but how Bim is specifically regulated to link TCR activation and apoptosis induction is unclear. Here we identify a murine T cell-specific genomic enhancer EBAB (Bub1-Acoxl-Bim), whose deletion leads to accumulation of thymocytes expressing high affinity TCRs. Consistently, EBAB knockout mice have defective negative selection and fail to delete autoreactive thymocytes in various settings, with this defect accompanied by reduced Bim expression and apoptosis induction. By contrast, EBAB is dispensable for maintaining peripheral T cell homeostasis via Bim-dependent pathways. Our data thus implicate EBAB as an important, developmental stage-specific regulator of Bim expression and apoptosis induction to enforce thymic negative selection and suppress autoimmunity. Our study unravels a part of genomic enhancer codes that underlie complex and context-dependent gene regulation in TCR signaling.


Assuntos
Autoimunidade/genética , Proteína 11 Semelhante a Bcl-2/genética , Elementos Facilitadores Genéticos/imunologia , Receptores de Antígenos de Linfócitos T/metabolismo , Timócitos/fisiologia , Animais , Apoptose/genética , Apoptose/imunologia , Autoimunidade/imunologia , Proteína 11 Semelhante a Bcl-2/metabolismo , Sistemas CRISPR-Cas/genética , Elementos Facilitadores Genéticos/genética , Feminino , Regulação da Expressão Gênica/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Modelos Animais , Receptores de Antígenos de Linfócitos T/imunologia , Transdução de Sinais/genética , Transdução de Sinais/imunologia , Timo/citologia , Timo/imunologia
8.
Cancer Treat Rev ; 77: 35-43, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31207478

RESUMO

Immunotherapeutic strategies have revolutionised cancer therapy in recent years, bringing meaningful improvements in outcomes for patients with previously intractable conditions. These successes have, however, been largely limited to certain types of liquid tumours and a small subset of solid tumours that are known to be particularly immunogenic. Broadening these advances across the majority of tumour indications, which are characterised by an immune-excluded, immune-deserted or immune-suppressed ('cold') phenotype, will require alternative approaches that are able to specifically address this unique biological environment. Several newer therapeutic modalities, including adoptive cell therapy and T cell redirecting bispecific molecules, are considered to hold particular promise and are being investigated in early phase clinical trials across various solid tumour indications. ImmTAC molecules are a novel class of T cell redirecting bispecific biologics that exploit TCR-based targeting of tumour cells; providing potent and highly specific access to the vast landscape of intracellular targets. The first of these reagents to reach the clinic, tebentafusp (IMCgp100), has generated demonstrable clinical efficacy in an immunologically cold solid tumour with a high unmet need. Here, we highlight the key elements of the ImmTAC platform that make it ideally positioned to overcome the cold tumour microenvironment in an off-the-shelf format.


Assuntos
Imunoterapia/métodos , Neoplasias/imunologia , Neoplasias/terapia , Receptores de Antígenos de Linfócitos T/imunologia , Linfócitos T/imunologia , Antígenos de Neoplasias/imunologia , Produtos Biológicos/administração & dosagem , Humanos , Imunoterapia Adotiva/métodos , Proteínas/imunologia , Anticorpos de Cadeia Única/imunologia , Antígeno gp100 de Melanoma/imunologia
9.
Nature ; 571(7764): 270-274, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31207604

RESUMO

Tumour-specific CD8 T cell dysfunction is a differentiation state that is distinct from the functional effector or memory T cell states1-6. Here we identify the nuclear factor TOX as a crucial regulator of the differentiation of tumour-specific T (TST) cells. We show that TOX is highly expressed in dysfunctional TST cells from tumours and in exhausted T cells during chronic viral infection. Expression of TOX is driven by chronic T cell receptor stimulation and NFAT activation. Ectopic expression of TOX in effector T cells in vitro induced a transcriptional program associated with T cell exhaustion. Conversely, deletion of Tox in TST cells in tumours abrogated the exhaustion program: Tox-deleted TST cells did not upregulate genes for inhibitory receptors (such as Pdcd1, Entpd1, Havcr2, Cd244 and Tigit), the chromatin of which remained largely inaccessible, and retained high expression of transcription factors such as TCF-1. Despite their normal, 'non-exhausted' immunophenotype, Tox-deleted TST cells remained dysfunctional, which suggests that the regulation of expression of inhibitory receptors is uncoupled from the loss of effector function. Notably, although Tox-deleted CD8 T cells differentiated normally to effector and memory states in response to acute infection, Tox-deleted TST cells failed to persist in tumours. We hypothesize that the TOX-induced exhaustion program serves to prevent the overstimulation of T cells and activation-induced cell death in settings of chronic antigen stimulation such as cancer.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/patologia , Diferenciação Celular/imunologia , Proteínas de Grupo de Alta Mobilidade/metabolismo , Proteínas de Homeodomínio/metabolismo , Neoplasias/imunologia , Animais , Linfócitos T CD8-Positivos/citologia , Linfócitos T CD8-Positivos/metabolismo , Epigênese Genética , Regulação Neoplásica da Expressão Gênica , Proteínas de Grupo de Alta Mobilidade/deficiência , Proteínas de Grupo de Alta Mobilidade/genética , Proteínas de Homeodomínio/genética , Humanos , Memória Imunológica , Linfócitos do Interstício Tumoral/citologia , Linfócitos do Interstício Tumoral/imunologia , Linfócitos do Interstício Tumoral/metabolismo , Linfócitos do Interstício Tumoral/patologia , Camundongos , Neoplasias/patologia , Fenótipo , Receptores de Antígenos de Linfócitos T/imunologia , Transcrição Genética
10.
Scand J Immunol ; 90(3): e12795, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31148206

RESUMO

Antigen-specific molecules of the immune system, namely antibodies, the membrane immunoglobulins (mIgs) of B cells and T cell receptors (TcRs), can all signal their interaction with antigen. There are different mechanisms by which this signalling could occur. These mechanisms can be divided into two general categories: allosteric and non-allosteric. In allosteric mechanisms, the monovalent binding of the antigen to the receptor triggers a conformational change at the binding site that is propagated to an invariant part of the receptor, a change recognized by a sensing unit. We argue allosteric mechanisms are implausible. Non-allosteric mechanisms depend on steric effects due to the antigen's size and/or multivalency. We consider two non-allosteric mechanisms by which the mIg of B cells has been envisaged to signal its interaction with antigen: the popular cross-linking model and the dissociation activation model. We argue, on the basis of both experimental observations and physiological considerations, that the dissociation activation model, developed by Reth and his colleagues, is uniquely plausible.


Assuntos
Anticorpos/imunologia , Antígenos/imunologia , Linfócitos B/imunologia , Sistema Imunitário/imunologia , Receptores de Antígenos de Linfócitos B/imunologia , Transdução de Sinais/imunologia , Humanos , Receptores de Antígenos de Linfócitos T/imunologia
11.
Mol Immunol ; 111: 209-219, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31096062

RESUMO

We have previously reported Israa, immune-system-released activating agent, as a novel gene nested in intron 8 of the mouse Zmiz1 gene. We have also shown that Israa encodes for a novel FYN-binding protein and might be involved in the regulation of T-cell activation. In this report, we demonstrate that Israa gene product regulates the expression of a pool of genes involved in T-cell activation and signaling. Real time PCR and GFP knock-in expression analysis showed that Israa is transcribed and expressed in the spleen mainly by CD3+CD8+ cells as well as in the thymus by CD3+ (DP and DN), CD4+SP and CD8+SP cells at different developmental stages. We also showed that Israa is downregulated in T-cells following activation of T-cell receptor. Using yeast two-hybrid analysis, we identified ELF1, a transcription factor involved in T-cell regulation, as an ISRAA-binding partner. Transcriptomic analysis of an EL4 cell line overexpressing ISRAA revealed differential expression of several genes involved in T-cell signaling, activation and development. Among these genes, Prkcb, Mib2, Fos, Ndfip2, Cxxc5, B2m, Gata3 and Cd247 were upregulated whereas Itk, Socs3, Tigit, Ifng, Il2ra and FoxJ1 were downregulated. Our findings support the existence in mouse of a novel FYN-related T-cell regulation pathway involving the product of an intron-nested gene.


Assuntos
Íntrons/imunologia , Ativação Linfocitária/imunologia , Linfócitos/imunologia , Linfocinas/imunologia , Genes Inseridos/imunologia , Transdução de Sinais/imunologia , Linfócitos T/imunologia , Animais , Complexo CD3/imunologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Linhagem Celular , Regulação para Baixo/imunologia , Feminino , Expressão Gênica/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Receptores de Antígenos de Linfócitos T/imunologia , Fatores de Transcrição/imunologia , Regulação para Cima/imunologia
12.
Nat Commun ; 10(1): 2042, 2019 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-31053703

RESUMO

Metabolic pathways that regulate T-cell function show promise as therapeutic targets in diverse diseases. Here, we show that at rest cultured human effector memory and central memory CD4+ T-cells have elevated levels of glycolysis and oxidative phosphorylation (OXPHOS), in comparison to naïve T-cells. Despite having low resting metabolic rates, naive T-cells respond to TCR stimulation with robust and rapid increases in glycolysis and OXPHOS. This early metabolic switch requires Akt activity to support increased rates of glycolysis and STAT5 activity for amino acid biosynthesis and TCA cycle anaplerosis. Importantly, both STAT5 inhibition and disruption of TCA cycle anaplerosis are associated with reduced IL-2 production, demonstrating the functional importance of this early metabolic program. Our results define STAT5 as a key node in modulating the early metabolic program following activation in naive CD4+ T-cells and in turn provide greater understanding of how cellular metabolism shapes T-cell responses.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptores de Antígenos de Linfócitos T/metabolismo , Fator de Transcrição STAT5/metabolismo , Linfócitos T CD4-Positivos/metabolismo , Células Cultivadas , Ciclo do Ácido Cítrico/imunologia , Glicólise/imunologia , Voluntários Saudáveis , Humanos , Memória Imunológica , Ativação Linfocitária , Fosforilação Oxidativa , Cultura Primária de Células , Proteínas Proto-Oncogênicas c-akt/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Fator de Transcrição STAT5/imunologia
13.
Nat Commun ; 10(1): 2087, 2019 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-31064990

RESUMO

T cells expressing CD19-targeting chimeric antigen receptors (CARs) reveal high efficacy in the treatment of B cell malignancies. Here, we report that T cell receptor fusion constructs (TRuCs) comprising an antibody-based binding domain fused to T cell receptor (TCR) subunits can effectively reprogram an intact TCR complex to recognize tumor surface antigens. Unlike CARs, TRuCs become a functional component of the TCR complex. TRuC-T cells kill tumor cells as potently as second-generation CAR-T cells, but at significant lower cytokine release and despite the absence of an extra co-stimulatory domain. TRuC-T cells demonstrate potent anti-tumor activity in both liquid and solid tumor xenograft models. In several models, TRuC-T cells are more efficacious than respective CAR-T cells. TRuC-T cells are shown to engage the signaling capacity of the entire TCR complex in an HLA-independent manner.


Assuntos
Imunoterapia Adotiva/métodos , Neoplasias/terapia , Receptores de Antígenos de Linfócitos T/imunologia , Receptores Artificiais/imunologia , Anticorpos de Cadeia Única/imunologia , Linfócitos T/imunologia , Animais , Antígenos CD19/imunologia , Antígenos de Neoplasias/imunologia , Linhagem Celular Tumoral , Feminino , Humanos , Camundongos , Camundongos Endogâmicos NOD , Neoplasias/imunologia , Cultura Primária de Células , Domínios Proteicos , Receptores de Antígenos de Linfócitos T/genética , Receptores Artificiais/genética , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/imunologia , Anticorpos de Cadeia Única/genética , Resultado do Tratamento , Ensaios Antitumorais Modelo de Xenoenxerto
14.
Nat Protoc ; 14(6): 1926-1943, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31101906

RESUMO

The identification of immunogenic neoantigens and their cognate T cells represents the most crucial and rate-limiting steps in the development of personalized cancer immunotherapies that are based on vaccination or on infusion of T cell receptor (TCR)-engineered T cells. Recent advances in deep-sequencing technologies and in silico prediction algorithms have allowed rapid identification of candidate neoepitopes. However, large-scale validation of putative neoepitopes and the isolation of reactive T cells are challenging because of the limited availablity of patient material and the low frequencies of neoepitope-specific T cells. Here we describe a standardized protocol for the induction of neoepitope-reactive T cells from healthy donor T cell repertoires, unaffected by the potentially immunosuppressive environment of the tumor-bearing host. Monocyte-derived dendritic cells (DCs) transfected with mRNA encoding candidate neoepitopes are used to prime autologous naive CD8+ T cells. Antigen-specific T cells that recognize endogenously processed and presented epitopes are detected using peptide-MHC (pMHC) multimers. Single multimer-positive T cells are sorted for the identification of TCR sequences, after an optional step that includes clonal expansion and functional characterization. The time required to identify neoepitope-specific T cells is 15 d, with an additional 2-4 weeks required for clonal expansion and downstream functional characterization. Identified neoepitopes and corresponding TCRs provide candidates for use in vaccination and TCR-based cancer immunotherapies, and datasets generated by this technology should be useful for improving algorithms to predict immunogenic neoantigens.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Células Dendríticas/imunologia , Epitopos/imunologia , Neoplasias/imunologia , Células Cultivadas , Células Dendríticas/metabolismo , Eletroporação/métodos , Epitopos/genética , Humanos , Imunoterapia/métodos , Neoplasias/terapia , RNA Mensageiro/genética , Receptores de Antígenos de Linfócitos T/análise , Receptores de Antígenos de Linfócitos T/imunologia , Transfecção/métodos
15.
Int J Nanomedicine ; 14: 2069-2089, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30988609

RESUMO

Purpose: Melanoma is the most aggressive form of skin cancer. Chemotherapy at a late stage fails due to low accumulation in tumors, indicating the need for targeted therapy. Materials and methods: To increase drug uptake by tumor cells, we have targeted doxorubicin-containing liposomes using a T-cell receptor (TCR)-like antibody (scFv G8 and Hyb3) directed against melanoma antigen A1 (MAGE-A1) presented by human leukocyte antigen A1 (M1/A1). With the use of flow cytometry and confocal microscopy, we have tested our formulation in vitro. In vivo pharmacokinetics was done in tumor-free nu/nu mice, while biodistribution and efficacy study was done in nu/nu mice xenograft. Results: We demonstrated two to five times higher binding and internalization of these immunoliposomes by M1+/A1+ melanoma cells in vitro in comparison with nontargeted liposomes. Cytotoxicity assay showed significant tumor cell kill at 10 µM doxorubicin (DXR) for targeted vs nontargeted liposomes. In vivo pharmacokinetics of nontargeted and targeted liposomes were similar, while accumulation of targeted liposomes was 2- to 2.5-fold and 6.6-fold enhanced when compared with nontargeted liposomes and free drug, respectively. Notably, we showed a superior antitumor activity of MAGE-A1-targeted DXR liposomes toward M1+/A1+ expressing tumors in mice compared with the treatment of M1-/A1+ tumors. Our results indicate that targeted liposomes showed better cytotoxicity in vitro and pharmacokinetics in vivo. Conclusion: Liposomes decorated with TCR-mimicking scFv antibodies effectively and selectively target antigen-positive melanoma. We showed that DXR-loaded liposomes coupled to anti-M1/-A1 scFv inflict a significant antitumor response. Targeting tumor cells specifically promotes internalization of drug-containing nanoparticles and may improve drug delivery and ultimately antitumor efficacy. Our data argue that targeting MAGE in A1 context, by nanosized carriers decorated with TCR-like antibodies mimicking scFv, can be used as a theragnostic platform for drug delivery, immunotherapy, and potentially imaging, and diagnosis of melanoma.


Assuntos
Apresentação do Antígeno/imunologia , Doxorrubicina/administração & dosagem , Sistemas de Liberação de Medicamentos , Antígeno HLA-A1/imunologia , Lipossomos/administração & dosagem , Melanoma/tratamento farmacológico , Nanopartículas/administração & dosagem , Animais , Antibióticos Antineoplásicos/administração & dosagem , Antibióticos Antineoplásicos/química , Antibióticos Antineoplásicos/farmacocinética , Doxorrubicina/química , Doxorrubicina/farmacocinética , Humanos , Lipossomos/química , Lipossomos/imunologia , Melanoma/imunologia , Camundongos Nus , Nanopartículas/química , Receptores de Antígenos de Linfócitos T/imunologia , Anticorpos de Cadeia Única/imunologia , Distribuição Tecidual , Células Tumorais Cultivadas
16.
J Exp Clin Cancer Res ; 38(1): 168, 2019 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-30995926

RESUMO

BACKGROUND: Chimeric antigen receptor (CAR)-engineered T cells have displayed outstanding performance in the treatment of patients with hematological malignancies. However, their efficacy against solid tumors has been largely limited. METHODS: In this study, human osteosarcoma cell lines were prepared, flow cytometry using antibodies against CD166 was performed on different cell samples. CD166-specific T cells were obtained by viral gene transfer of corresponding DNA plasmids and selectively expanded using IL-2 and IL-15. The ability of CD166.BBζ CAR-T cells to kill CD166+ osteosarcoma cells was evaluated in vitro and in vivo. RESULTS: CD166 was selectively expressed on four different human osteosarcoma cell lines, indicating its role as the novel target for CAR-T cell therapy. CD166.BBζ CAR-T cells killed osteosarcoma cell lines in vitro; the cytotoxicity correlated with the level of CD166 expression on the tumor cells. Intravenous injection of CD166.BBζ CAR-T cells into mice resulted in the regression of the tumor with no obvious toxicity. CONCLUSIONS: Together, the data suggest that CD166.BBζ CAR-T cells may serve as a new therapeutic strategy in the future clinical practice for the treatment of osteosarcoma.


Assuntos
Antígenos CD/administração & dosagem , Moléculas de Adesão Celular Neuronais/administração & dosagem , Proteínas Fetais/administração & dosagem , Imunoterapia Adotiva/métodos , Osteossarcoma/terapia , Receptores de Antígenos de Linfócitos T/imunologia , Receptores de Antígenos Quiméricos/imunologia , Ligante 4-1BB/administração & dosagem , Ligante 4-1BB/genética , Ligante 4-1BB/imunologia , Animais , Antígenos CD/genética , Antígenos CD/imunologia , Moléculas de Adesão Celular Neuronais/genética , Moléculas de Adesão Celular Neuronais/imunologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proteínas Fetais/genética , Proteínas Fetais/imunologia , Citometria de Fluxo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Interleucina-15/imunologia , Interleucina-2/genética , Interleucina-2/imunologia , Camundongos , Osteossarcoma/genética , Osteossarcoma/imunologia , Osteossarcoma/patologia , Receptores de Antígenos de Linfócitos T/administração & dosagem , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos Quiméricos/administração & dosagem , Receptores de Antígenos Quiméricos/genética , Transdução de Sinais/imunologia , Linfócitos T/imunologia , Ensaios Antitumorais Modelo de Xenoenxerto
17.
Cancer Discov ; 9(4): 466-468, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30936218

RESUMO

Treatment with chimeric antigen receptor T cells has led to impressive and durable responses in adult and pediatric malignancies refractory to conventional therapy; however, only patients with a handful of cancers have responded thus far and significant disparities exist between the response rates of pediatric and adult patients. A new extensive analysis of pediatric patient T-cell subsets at diagnosis and throughout the patients' chemotherapy courses in a variety of solid and hematologic malignancies sheds new light on the intrinsic T-cell deficits that may be partly to blame.See related article by Das et al., p. 492.


Assuntos
Neoplasias Hematológicas , Neoplasias/imunologia , Adulto , Terapia Baseada em Transplante de Células e Tecidos , Criança , Humanos , Imunoterapia Adotiva , Receptores de Antígenos de Linfócitos T/imunologia
18.
Oncol Rep ; 41(6): 3455-3463, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30942469

RESUMO

CD19 chimeric antigen receptor (CAR) T cell therapy has changed the outcomes of relapsed/refractory B­cell leukemia and lymphoma. However, its efficacy in patients with relapsed/refractory non­Hodgkin lymphoma (NHL) has been less impressive compared with that in patients with acute lymphoid leukemia. Furthermore, immune checkpoints have a critical role in the immune system. Several clinical trials have confirmed the dramatic effects of programmed death­1/programmed death­ligand 1 (PD­1/PD­L1) inhibitors in numerous malignancies, but the immune­associated adverse events of PD­1/PD­L1 inhibitors may occur in a number of systems. The aim of the present study was to investigate the combination of CD19 CAR­T cells with a reduced dose of PD­1 inhibitor. This method is expected to overcome the side-effects of PD­1 inhibitors, while maintaining therapeutic efficacy. The findings demonstrated that a reduced dose of PD­1 inhibitor did not affect the transfection rate, proliferation rate or cytokine secretion of CD19 CAR­T cells. An interesting finding of the present study was that the number of PD­1­positive cells CAR­T cells, measured by flow cytometry, declined when they were cultured in vitro, but returned to high levels with gradual prolongation of the co­culture time of CD19 CAR­T cells with lymphoma cells; however, there was no change in the mRNA expression of T cells and CAR­T cells during this process. This phenomenon may be one of the reasons why the curative effect of CAR­T cells on B­cell lymphoma is unsatisfactory compared with B­cell leukemia. The synergistic effect of a reduced­dose PD­1 inhibitor combined with CD19 CAR­T cells from T cells highly expressing PD­1 was confirmed in a mouse trial. Mice in the combined treatment group achieved the longest survival time. In this group, the proportion of CAR­T cells and the level of interleukin­6 were higher compared with those in the CAR­T cell group. In conclusion, a reduced dose of a PD­1 inhibitor combined with CD19 CAR­T cells appears to be a promising treatment option for relapsed/refractory B­NHL exhibiting high PD­1 expression by T cells. This method may achieve good clinical efficacy while reducing the side-effects of PD­1 inhibitors.


Assuntos
Linfoma/terapia , Nivolumabe/administração & dosagem , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Adulto , Antígenos CD19/genética , Antígeno B7-H1/antagonistas & inibidores , Antígeno B7-H1/genética , Antígeno B7-H1/imunologia , Proliferação de Células/efeitos dos fármacos , Feminino , Citometria de Fluxo , Regulação Neoplásica da Expressão Gênica/genética , Regulação Neoplásica da Expressão Gênica/imunologia , Humanos , Imunoterapia Adotiva/métodos , Linfoma/genética , Linfoma/imunologia , Linfoma/patologia , Masculino , Pessoa de Meia-Idade , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/imunologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Receptor de Morte Celular Programada 1/genética , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos de Linfócitos T/imunologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Ensaios Antitumorais Modelo de Xenoenxerto
19.
Nat Commun ; 10(1): 1019, 2019 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-30833553

RESUMO

The αß T cell receptor (TCR) repertoire on mature T cells is selected in the thymus, but the basis for thymic selection of MHC-restricted TCRs from a randomly generated pre-selection repertoire is not known. Here we perform comparative repertoire sequence analyses of pre-selection and post-selection TCR from multiple MHC-sufficient and MHC-deficient mouse strains, and find that MHC-restricted and MHC-independent TCRs are primarily distinguished by features in their non-germline CDR3 regions, with many pre-selection CDR3 sequences not compatible with MHC-binding. Thymic selection of MHC-independent TCR is largely unconstrained, but the selection of MHC-specific TCR is restricted by both CDR3 length and specific amino acid usage. MHC-restriction disfavors TCR with CDR3 longer than 13 amino acids, limits positively charged and hydrophobic amino acids in CDR3ß, and clonally deletes TCRs with cysteines in their CDR3 peptide-binding regions. Together, these MHC-imposed structural constraints form the basis to shape VDJ recombination sequences into MHC-restricted repertoires.


Assuntos
Regiões Determinantes de Complementaridade/química , Regiões Determinantes de Complementaridade/imunologia , Complexo Principal de Histocompatibilidade/imunologia , Receptores de Antígenos de Linfócitos T/química , Receptores de Antígenos de Linfócitos T/imunologia , Timo/imunologia , Sequência de Aminoácidos , Animais , Regiões Determinantes de Complementaridade/genética , Ativação Linfocitária , Complexo Principal de Histocompatibilidade/genética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptores de Antígenos de Linfócitos T/genética , Análise de Sequência de Proteína , Linfócitos T/imunologia , Linfócitos T/metabolismo , Recombinação V(D)J
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