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1.
Mol Immunol ; 127: 112-123, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32961421

RESUMO

A highly diverse repertoire of T cell antigen receptors (TCR) is created in the thymus by recombination of gene segments and the insertion or deletion of nucleotides at the junctions. Using next-generation TCR sequencing we define here the features of recombination and selection in the human TCRα and TCRß locus, and show that a strikingly high proportion of the repertoire is shared by unrelated individuals. The thymic TCRα nucleotide repertoire was more diverse than TCRß, with 4.1 × 106 vs. 0.81 × 106 unique clonotypes, and contained nonproductive clonotypes at a higher frequency (69.2% vs. 21.2%). The convergence of distinct nucleotide clonotypes to the same amino acid sequences was higher in TCRα than in TCRß repertoire (1.45 vs. 1.06 nucleotide sequences per amino acid sequence in thymus). The gene segment usage was biased, and generally all individuals favored the same genes in both TCRα and TCRß loci. Despite the high diversity, a large fraction of the repertoire was found in more than one donor. The shared fraction was bigger in TCRα than TCRß repertoire, and more common in in-frame sequences than in nonproductive sequences. Thus, both biases in rearrangement and thymic selection are likely to contribute to the generation of shared repertoire in humans.


Assuntos
Impressão Genômica , Linfócitos T/imunologia , Timo/citologia , Sequência de Bases , Células Clonais , Regiões Determinantes de Complementaridade/genética , Feminino , Variação Genética , Humanos , Lactente , Recém-Nascido , Masculino , Mutagênese Insercional , Probabilidade , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Recombinação Genética/genética
2.
PLoS One ; 15(9): e0238875, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32903281

RESUMO

To facilitate preclinical testing of T-cell receptors (TCRs) derived from tumor-reactive T-cell clones it is necessary to develop convenient and rapid cloning strategies for the generation of TCR expression constructs. Herein, we describe a pDONR™221 vector backbone allowing to generate Gateway™ compatible entry clones encoding optimized bicistronic αßTCR constructs. It harbors P2A-linked TCR constant regions and head-to-head-oriented recognition sites of the Type IIS restriction enzymes BsmBI and BsaI for seamless cloning of the TCRα and TCRß V(D)J regions, respectively. Additional well-established TCR optimizations were incorporated to enhance TCR functionality. This included replacing of the human αßTCR constant regions with their codon-optimized murine counterparts for chimerization, addition of a second interchain disulfide bond and arrangement of the TCR chains in the order ß-P2A-α. We exemplified the utility of our vector backbone by cloning and functional testing of three melanoma-reactive TCRs in primary human T cells.


Assuntos
Clonagem Molecular/métodos , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Retroviridae/genética , Linfócitos T/citologia , Animais , Células COS , Linhagem Celular , Chlorocebus aethiops , Técnicas de Cocultura , Vetores Genéticos/genética , Células HEK293 , Humanos , Linfócitos T/imunologia , Linfócitos T/virologia , Transdução Genética , Recombinação V(D)J
3.
Nat Commun ; 11(1): 4767, 2020 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-32958743

RESUMO

Psoriatic arthritis (PsA) is a debilitating immune-mediated inflammatory arthritis of unknown pathogenesis commonly affecting patients with skin psoriasis. Here we use complementary single-cell approaches to study leukocytes from PsA joints. Mass cytometry demonstrates a 3-fold expansion of memory CD8 T cells in the joints of PsA patients compared to peripheral blood. Meanwhile, droplet-based and plate-based single-cell RNA sequencing of paired T cell receptor alpha and beta chain sequences show pronounced CD8 T cell clonal expansions within the joints. Transcriptome analyses find these expanded synovial CD8 T cells to express cycling, activation, tissue-homing and tissue residency markers. T cell receptor sequence comparison between patients identifies clonal convergence. Finally, chemokine receptor CXCR3 is upregulated in the expanded synovial CD8 T cells, while two CXCR3 ligands, CXCL9 and CXCL10, are elevated in PsA synovial fluid. Our data thus provide a quantitative molecular insight into the cellular immune landscape of psoriatic arthritis.


Assuntos
Artrite Psoriásica/imunologia , Linfócitos T CD8-Positivos/imunologia , Seleção Clonal Mediada por Antígeno , Receptores de Retorno de Linfócitos/metabolismo , Líquido Sinovial/imunologia , Artrite Psoriásica/sangue , Linfócitos T CD8-Positivos/metabolismo , Perfilação da Expressão Gênica , Humanos , Memória Imunológica , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Receptores de Antígenos de Linfócitos T alfa-beta/metabolismo , Receptores de Quimiocinas/metabolismo , Receptores de Retorno de Linfócitos/genética , Análise de Célula Única , Membrana Sinovial/imunologia
4.
Nucleic Acids Res ; 48(17): 9621-9636, 2020 09 25.
Artigo em Inglês | MEDLINE | ID: mdl-32853367

RESUMO

The regulation of T cell receptor Tcra gene rearrangement has been extensively studied. The enhancer Eα plays an essential role in Tcra rearrangement by establishing a recombination centre in the Jα array and a chromatin hub for interactions between Vα and Jα genes. But the mechanism of the Eα and its downstream CTCF binding site (here named EACBE) in dynamic chromatin regulation is unknown. The Hi-C data showed that the EACBE is located at the sub-TAD boundary which separates the Tcra-Tcrd locus and the downstream region including the Dad1 gene. The EACBE is required for long-distance regulation of the Eα on the proximal Vα genes, and its deletion impaired the Tcra rearrangement. We also noticed that the EACBE and Eα regulate the genes in the downstream sub-TAD via asymmetric chromatin extrusion. This study provides a new insight into the role of CTCF binding sites at TAD boundaries in gene regulation.


Assuntos
Fator de Ligação a CCCTC/metabolismo , Cromatina/metabolismo , Elementos Facilitadores Genéticos , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Receptores de Antígenos de Linfócitos T gama-delta/genética , Animais , Proteínas Reguladoras de Apoptose/genética , Sítios de Ligação , Fator de Ligação a CCCTC/genética , Cromatina/genética , Regulação da Expressão Gênica , Rearranjo Gênico da Cadeia alfa dos Receptores de Antígenos dos Linfócitos T , Proteínas de Homeodomínio/genética , Proteínas de Membrana/genética , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Timo/citologia
5.
Proc Natl Acad Sci U S A ; 117(35): 21336-21345, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32796106

RESUMO

Each [Formula: see text]T cell receptor (TCR) functions as a mechanosensor. The TCR is comprised of a clonotypic TCR[Formula: see text] ligand-binding heterodimer and the noncovalently associated CD3 signaling subunits. When bound by ligand, an antigenic peptide arrayed by a major histocompatibility complex molecule (pMHC), the TCR[Formula: see text] has a longer bond lifetime under piconewton-level loads. The atomistic mechanism of this "catch bond" behavior is unknown. Here, we perform molecular dynamics simulation of a TCR[Formula: see text]-pMHC complex and its variants under physiologic loads to identify this mechanism and any attendant TCR[Formula: see text] domain allostery. The TCR[Formula: see text]-pMHC interface is dynamically maintained by contacts with a spectrum of occupancies, introducing a level of control via relative motion between Vα and Vß variable domains containing the pMHC-binding complementarity-determining region (CDR) loops. Without adequate load, the interfacial contacts are unstable, whereas applying sufficient load suppresses Vα-Vß motion, stabilizing the interface. A second level of control is exerted by Cα and Cß constant domains, especially Cß and its protruding FG-loop, that create mismatching interfaces among the four TCR[Formula: see text] domains and with a pMHC ligand. Applied load enhances fit through deformation of the TCR[Formula: see text] molecule. Thus, the catch bond involves the entire TCR[Formula: see text] conformation, interdomain motion, and interfacial contact dynamics, collectively. This multilayered architecture of the machinery fosters fine-tuning of cellular response to load and pMHC recognition. Since the germline-derived TCR[Formula: see text] ectodomain is structurally conserved, the proposed mechanism can be universally adopted to operate under load during immune surveillance by diverse [Formula: see text]TCRs constituting the T cell repertoire.


Assuntos
Complexo Principal de Histocompatibilidade , Simulação de Dinâmica Molecular , Receptores de Antígenos de Linfócitos T alfa-beta/metabolismo , Humanos , Ligantes , Mecanotransdução Celular , Linfócitos T/metabolismo
6.
Science ; 369(6506): 942-949, 2020 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-32820120

RESUMO

Gamma delta (γδ) T cells infiltrate most human tumors, but current immunotherapies fail to exploit their in situ major histocompatibility complex-independent tumoricidal potential. Activation of γδ T cells can be elicited by butyrophilin and butyrophilin-like molecules that are structurally similar to the immunosuppressive B7 family members, yet how they regulate and coordinate αß and γδ T cell responses remains unknown. Here, we report that the butyrophilin BTN3A1 inhibits tumor-reactive αß T cell receptor activation by preventing segregation of N-glycosylated CD45 from the immune synapse. Notably, CD277-specific antibodies elicit coordinated restoration of αß T cell effector activity and BTN2A1-dependent γδ lymphocyte cytotoxicity against BTN3A1+ cancer cells, abrogating malignant progression. Targeting BTN3A1 therefore orchestrates cooperative killing of established tumors by αß and γδ T cells and may present a treatment strategy for tumors resistant to existing immunotherapies.


Assuntos
Antígenos CD/imunologia , Butirofilinas/antagonistas & inibidores , Butirofilinas/imunologia , Linfócitos Intraepiteliais/imunologia , Neoplasias Ovarianas/imunologia , Neoplasias Ovarianas/terapia , Animais , Anticorpos Monoclonais/uso terapêutico , Antígenos CD/genética , Butirofilinas/genética , Feminino , Humanos , Imunoterapia/métodos , Camundongos , Camundongos Transgênicos , Receptores de Antígenos de Linfócitos T alfa-beta/imunologia , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
7.
Nat Commun ; 11(1): 4089, 2020 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-32796830

RESUMO

Clonal expansions occur in the persistent HIV reservoir as shown by the duplication of proviral integration sites. However, the source of the proliferation of HIV-infected cells remains unclear. Here, we analyze the TCR repertoire of single HIV-infected cells harboring translation-competent proviruses in longitudinal samples from eight individuals on antiretroviral therapy (ART). When compared to uninfected cells, the TCR repertoire of reservoir cells is heavily biased: expanded clonotypes are present in all individuals, account for the majority of reservoir cells and are often maintained over time on ART. Infected T cell clones are detected at low frequencies in the long-lived central memory compartment and overrepresented in the most differentiated memory subsets. Our results indicate that clonal expansions highly contribute to the persistence of the HIV reservoir and suggest that reservoir cells displaying a differentiated phenotype are the progeny of infected central memory cells undergoing antigen-driven clonal expansion during ART.


Assuntos
Antirretrovirais/uso terapêutico , Infecções por HIV/genética , Receptores de Antígenos de Linfócitos T alfa-beta/metabolismo , Adulto , Células Cultivadas , Feminino , Citometria de Fluxo , Infecções por HIV/tratamento farmacológico , HIV-1/efeitos dos fármacos , HIV-1/genética , HIV-1/patogenicidade , Humanos , Masculino , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Carga Viral , Replicação Viral/efeitos dos fármacos , Replicação Viral/genética
8.
PLoS One ; 15(7): e0236366, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32702062

RESUMO

Deep sequencing of T-cell receptor (TCR) genes is powerful at profiling immune repertoire. To prepare a TCR sequencing library, multiplex polymerase chain reaction (mPCR) is widely applied and is highly efficient. That is, most mPCR products contain the region critical for antigen recognition, which also indicates regular V(D)J recombination. Multiplex PCR, however, may suffer from primer bias. A promising alternative is 5'-RACE, which avoids primer bias by applying only one primer pair. In 5'-RACE data, however, non-regular V(D)J recombination (e.g., TCR sequences without a V gene segment) has been observed and the frequency varies (30-80%) between studies. This suggests that the cause of or how to reduce non-regular TCR sequences is not yet well known by the science community. Although it is possible to speculate the cause by comparing the 5'-RACE protocols, careful experimental confirmation is needed and such a systematic study is still not available. Here, we examined the 5'-RACE protocol of a commercial kit and demonstrated how a modification increased the fraction of regular TCR-ß sequences to >85%. We also found a strong linear correlation between the fraction of short DNA fragments and the percentage of non-regular TCR-ß sequences, indicating that the presence of short DNA fragments in the library was the main cause of non-regular TCR-ß sequences. Therefore, thorough removal of short DNA fragments from a 5'-RACE library is the key to high data efficiency. We highly recommend conducting a fragment length analysis before sequencing, and the fraction of short DNA fragments can be used to estimate the percentage of non-regular TCR sequences. As deep sequencing of TCR genes is still relatively expensive, good quality control should be valuable.


Assuntos
Sequência de Aminoácidos/genética , DNA/genética , Rearranjo Gênico da Cadeia beta dos Receptores de Antígenos dos Linfócitos T/genética , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Sequência de Bases , Fragmentação do DNA , DNA Complementar/genética , Rearranjo Gênico da Cadeia beta dos Receptores de Antígenos dos Linfócitos T/imunologia , Humanos , Receptores de Antígenos de Linfócitos T alfa-beta/imunologia
9.
Proc Natl Acad Sci U S A ; 117(25): 14342-14353, 2020 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-32513716

RESUMO

Immature T cells undergo a process of positive selection in the thymus when their new T cell receptor (TCR) engages and signals in response to self-peptides. As the T cell matures, a slew of negative regulatory molecules, including the inhibitory surface glycoprotein CD5, are up-regulated in proportion to the strength of the self-peptide signal. Together these regulators dampen TCR-proximal signaling and help avoid any subsequent peripheral activation of T cells by self-peptides. Paradoxically, antigen-specific T cells initially expressing more CD5 (CD5hi) have been found to better persist as effector/memory cells after a peripheral challenge. The molecular mechanisms underlying such a duality in CD5 function is not clear. We found that CD5 alters the basal activity of the NF-κB signaling in resting peripheral T cells. When CD5 was conditionally ablated, T cells were unable to maintain higher expression of the cytoplasmic NF-κB inhibitor IκBα. Consistent with this, resting CD5hi T cells expressed more of the NF-κB p65 protein than CD5lo cells, without significant increases in transcript levels, in the absence of TCR signals. This posttranslationally stabilized cellular NF-κB depot potentially confers a survival advantage to CD5hi T cells over CD5lo ones. Taken together, these data suggest a two-step model whereby the strength of self-peptide-induced TCR signal lead to the up-regulation of CD5, which subsequently maintains a proportional reserve of NF-κB in peripheral T cells poised for responding to agonistic antigen-driven T cell activation.


Assuntos
Antígenos CD5/metabolismo , Regulação da Expressão Gênica no Desenvolvimento/imunologia , Inibidor de NF-kappaB alfa/metabolismo , Proteína Tirosina Fosfatase não Receptora Tipo 6/metabolismo , Linfócitos T/imunologia , Transferência Adotiva , Animais , Apresentação do Antígeno/imunologia , Antígenos CD5/genética , Linhagem Celular Tumoral , Separação Celular , Sobrevivência Celular/imunologia , Feminino , Citometria de Fluxo , Lipopolissacarídeos/imunologia , Ativação Linfocitária , Camundongos , Camundongos Knockout , Modelos Animais , Cultura Primária de Células , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Receptores de Antígenos de Linfócitos T alfa-beta/metabolismo , Transdução de Sinais/imunologia , Linfócitos T/metabolismo , Linfócitos T/transplante , Timo/citologia , Timo/crescimento & desenvolvimento , Timo/imunologia , Fator de Transcrição RelA/metabolismo , Regulação para Cima
10.
Proc Natl Acad Sci U S A ; 117(27): 15809-15817, 2020 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-32571924

RESUMO

Src family kinase Lck plays critical roles during T cell development and activation, as it phosphorylates the TCR/CD3 complex to initiate TCR signaling. Lck is present either in coreceptor-bound or coreceptor-unbound (free) forms, and we here present evidence that the two pools of Lck have different molecular properties. We discovered that the free Lck fraction exhibited higher mobility than CD8α-bound Lck in OT-I T hybridoma cells. The free Lck pool showed more activating Y394 phosphorylation than the coreceptor-bound Lck pool. Consistent with this, free Lck also had higher kinase activity, and free Lck mediated higher T cell activation as compared to coreceptor-bound Lck. Furthermore, the coreceptor-Lck coupling was independent of TCR activation. These findings give insights into the initiation of TCR signaling, suggesting that changes in coreceptor-Lck coupling constitute a mechanism for regulation of T cell sensitivity.


Assuntos
Proteína Tirosina Quinase p56(lck) Linfócito-Específica/genética , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Linfócitos T/metabolismo , Quinases da Família src/genética , Animais , Linfócitos T CD8-Positivos/imunologia , Diferenciação Celular/genética , Hibridomas/imunologia , Ativação Linfocitária/genética , Proteína Tirosina Quinase p56(lck) Linfócito-Específica/imunologia , Camundongos , Fosforilação/genética , Ligação Proteica/genética , Complexo Receptor-CD3 de Antígeno de Linfócitos T/genética , Complexo Receptor-CD3 de Antígeno de Linfócitos T/imunologia , Transdução de Sinais , Linfócitos T/imunologia
11.
Nat Commun ; 11(1): 2859, 2020 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-32503973

RESUMO

Mature double negative (DN) T cells are a population of αß T cells that lack CD4 and CD8 coreceptors and contribute to systemic lupus erythematosus (SLE). The splenic marginal zone macrophages (MZMs) are important for establishing immune tolerance, and loss of their number or function contributes to the progression of SLE. Here we show that loss of MZMs impairs the tolerogenic clearance of apoptotic cells and alters the serum cytokine profile, which in turn provokes the generation of DN T cells from self-reactive CD8+ T cells. Increased Ki67 expression, narrowed TCR V-beta repertoire usage and diluted T-cell receptor excision circles confirm that DN T cells from lupus-prone mice and patients with SLE undergo clonal proliferation and expansion in a self-antigen dependent manner, which supports the shared mechanisms for their generation. Collectively, our results provide a link between the loss of MZMs and the expansion of DN T cells, and indicate possible strategies to prevent the development of SLE.


Assuntos
Autoantígenos/imunologia , Interleucina-17/metabolismo , Lúpus Eritematoso Sistêmico/imunologia , Subpopulações de Linfócitos T/imunologia , Transferência Adotiva , Animais , Autoantígenos/metabolismo , Modelos Animais de Doenças , Progressão da Doença , Feminino , Humanos , Tolerância Imunológica , Antígeno Ki-67/imunologia , Antígeno Ki-67/metabolismo , Lúpus Eritematoso Sistêmico/sangue , Macrófagos/imunologia , Camundongos , Camundongos Knockout , Receptores de Antígenos de Linfócitos T alfa-beta/metabolismo , Subpopulações de Linfócitos T/metabolismo
12.
Scand J Immunol ; 92(2): e12912, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32458431

RESUMO

Immune processes in liver transplantation remain poorly understood. Acute allograft rejection in liver transplantation is a kind of T cell-mediated inflammatory disease accompanied by inflammatory cell infiltration. However, the effect of acute allograft rejection on the immunological characteristics of TCRs in peripheral blood mononuclear cell is unknown. In this study, we characterized the pattern of the human T cell receptor beta chain (TRB) and immunoglobulin heavy chain (IGH) complementarity-determining region 3 (CDR3) repertoires via high-throughput sequencing in 11 acute allograft rejection (AG) cases, 23 patients with stable allograft liver function (ST) who had liver transplantation performed and 20 healthy controls (HC). The diversity of TRB-CDR3 was significantly reduced in the AG group compared with the ST group and healthy controls (HC). The CDR3 and N-addition length distribution were not significantly different between the AG and ST groups. However, N-addition length distribution was significantly changed compared to HC. It seemed that AG used more short N-additions and healthy people used more long N-additions in TRB-CDR3 repertoire. Our findings suggested that the TRB-CDR3 region of AG had distinctive V gene use compared with that of HC. The characteristics of ST seemed to be in between those of AG and HC although the difference is not significant. Cluster analysis showed that the TRB repertoire could not effectively distinguish AG from ST. This research might give to a better understanding of the immune process of liver transplantation.


Assuntos
Regiões Determinantes de Complementaridade/imunologia , Rejeição de Enxerto/imunologia , Cadeias Pesadas de Imunoglobulinas/imunologia , Transplante de Fígado , Receptores de Antígenos de Linfócitos T alfa-beta/imunologia , Adulto , Regiões Determinantes de Complementaridade/genética , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Cadeias Pesadas de Imunoglobulinas/genética , Masculino , Pessoa de Meia-Idade , Receptores de Antígenos de Linfócitos T alfa-beta/genética
13.
J Leukoc Biol ; 107(6): 1057-1067, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32362028

RESUMO

γδ T cells contribute to the immune response against many cancers, notably through their powerful effector functions that lead to the elimination of tumor cells and the recruitment of other immune cells. However, their presence in the tumor microenvironment has been associated with poor prognosis in breast, colon, and pancreatic cancer, suggesting that γδ T cells may also display pro-tumor activities. Here, we identified in blood from healthy donors a subpopulation of Vδ1T cells that represents around 20% of the whole Vδ1 population, expresses CD73, and displays immunosuppressive phenotype and functions (i.e., production of immunosuppressive molecules, such as IL-10, adenosine, and the chemotactic factor IL-8, and inhibition of αß T cell proliferation). We then found that in human breast tumors, γδ T cells were present particularly in late stage breast cancer samples, and that ∼20% of tumor-infiltrating γδ T cells expressed CD73. Taken together, these results suggest that regulatory γδ T cells are present in the breast cancer microenvironment and may display immunosuppressive functions through the production of immunosuppressive molecules, such as IL-10, IL-8, and adenosine, thus promoting tumor growth.


Assuntos
5'-Nucleotidase/imunologia , Neoplasias da Mama/imunologia , Linhagem da Célula/imunologia , Regulação Neoplásica da Expressão Gênica , Linfócitos do Interstício Tumoral/imunologia , Receptores de Antígenos de Linfócitos T gama-delta/imunologia , Linfócitos T Reguladores/imunologia , 5'-Nucleotidase/genética , Adenosina/imunologia , Adenosina/metabolismo , Adolescente , Adulto , Idoso , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Estudos de Casos e Controles , Diferenciação Celular , Linhagem da Célula/genética , Feminino , Proteínas Ligadas por GPI/genética , Proteínas Ligadas por GPI/imunologia , Humanos , Interleucina-10/genética , Interleucina-10/imunologia , Interleucina-8/genética , Interleucina-8/imunologia , Ativação Linfocitária , Linfócitos do Interstício Tumoral/patologia , Pessoa de Meia-Idade , Cultura Primária de Células , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Receptores de Antígenos de Linfócitos T alfa-beta/imunologia , Receptores de Antígenos de Linfócitos T gama-delta/genética , Transdução de Sinais , Linfócitos T Reguladores/patologia , Microambiente Tumoral/genética , Microambiente Tumoral/imunologia
14.
Nat Biotechnol ; 38(5): 609-619, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32393905

RESUMO

T cells engineered to express antigen-specific T cell receptors (TCRs) are potent therapies for viral infections and cancer. However, efficient identification of clinical candidate TCRs is complicated by the size and complexity of T cell repertoires and the challenges of working with primary T cells. Here we present a high-throughput method to identify TCRs with high functional avidity from diverse human T cell repertoires. The approach used massively parallel microfluidics to generate libraries of natively paired, full-length TCRαß clones, from millions of primary T cells, which were then expressed in Jurkat cells. The TCRαß-Jurkat libraries enabled repeated screening and panning for antigen-reactive TCRs using peptide major histocompatibility complex binding and cellular activation. We captured more than 2.9 million natively paired TCRαß clonotypes from six healthy human donors and identified rare (<0.001% frequency) viral-antigen-reactive TCRs. We also mined a tumor-infiltrating lymphocyte sample from a patient with melanoma and identified several tumor-specific TCRs, which, after expression in primary T cells, led to tumor cell killing.


Assuntos
Antígenos/análise , Receptores de Antígenos de Linfócitos T alfa-beta/imunologia , Linfócitos T/citologia , Engenharia Celular , Biblioteca Gênica , Humanos , Células Jurkat , Linfócitos do Interstício Tumoral/imunologia , Melanoma/imunologia , Linfócitos T/imunologia , Vírus/imunologia
15.
Nat Commun ; 11(1): 1522, 2020 03 23.
Artigo em Inglês | MEDLINE | ID: mdl-32251280

RESUMO

Foxp3+ regulatory T (Treg) cells are essential for maintaining peripheral tolerance and preventing autoimmunity. While genetic factors may predispose for autoimmunity, additional environmental triggers, such as viral infections, are usually required to initiate the onset of disease. Here, we show that viral infection with LCMV results in type I IFN-dependent Treg cell loss that is rapidly compensated by the conversion and expansion of Vß5+ conventional T cells into iTreg cells. Using Vß5-deficient mice, we show that these Vß5+ iTreg cells are dispensable for limiting anti-viral immunity. Rather, the delayed replenishment of Treg cells in Vß5-deficient mice compromises suppression of microbiota-dependent activation of CD8+ T cells, resulting in colitis. Importantly, recovery from clinical symptoms in IBD patients is marked by expansion of the corresponding Vß2+ Treg population in humans. Collectively, we provide a link between a viral trigger and an impaired Treg cell compartment resulting in the initiation of immune pathology.


Assuntos
Infecções por Arenaviridae/imunologia , Autoimunidade , Linfócitos T CD8-Positivos/imunologia , Colite/imunologia , Vírus da Coriomeningite Linfocítica/imunologia , Linfócitos T Reguladores/imunologia , Animais , Infecções por Arenaviridae/complicações , Linhagem Celular , Colite/microbiologia , Colo/imunologia , Colo/microbiologia , Fatores de Transcrição Forkhead/metabolismo , Microbioma Gastrointestinal/imunologia , Voluntários Saudáveis , Interações entre Hospedeiro e Microrganismos/imunologia , Humanos , Interferon Tipo I/imunologia , Interferon Tipo I/metabolismo , Mucosa Intestinal/imunologia , Mucosa Intestinal/microbiologia , Ativação Linfocitária/genética , Masculino , Camundongos , Camundongos Knockout , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Receptores de Antígenos de Linfócitos T alfa-beta/metabolismo , Linfócitos T Reguladores/metabolismo
16.
Proc Natl Acad Sci U S A ; 117(19): 10465-10475, 2020 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-32341160

RESUMO

The antigen-presenting molecule MR1 presents riboflavin-based metabolites to Mucosal-Associated Invariant T (MAIT) cells. While MR1 egress to the cell surface is ligand-dependent, the ability of small-molecule ligands to impact on MR1 cellular trafficking remains unknown. Arising from an in silico screen of the MR1 ligand-binding pocket, we identify one ligand, 3-([2,6-dioxo-1,2,3,6-tetrahydropyrimidin-4-yl]formamido)propanoic acid, DB28, as well as an analog, methyl 3-([2,6-dioxo-1,2,3,6-tetrahydropyrimidin-4-yl]formamido)propanoate, NV18.1, that down-regulate MR1 from the cell surface and retain MR1 molecules in the endoplasmic reticulum (ER) in an immature form. DB28 and NV18.1 compete with the known MR1 ligands, 5-OP-RU and acetyl-6-FP, for MR1 binding and inhibit MR1-dependent MAIT cell activation. Crystal structures of the MAIT T cell receptor (TCR) complexed with MR1-DB28 and MR1-NV18.1, show that these two ligands reside within the A'-pocket of MR1. Neither ligand forms a Schiff base with MR1 molecules; both are nevertheless sequestered by a network of hydrophobic and polar contacts. Accordingly, we define a class of compounds that inhibits MR1 cellular trafficking.


Assuntos
Antígenos de Histocompatibilidade Classe I/metabolismo , Antígenos de Histocompatibilidade Menor/metabolismo , Células T Invariáveis Associadas à Mucosa/metabolismo , Apresentação do Antígeno , Linhagem Celular , Membrana Celular/metabolismo , Regulação para Baixo , Regulação da Expressão Gênica/genética , Humanos , Ligantes , Ativação Linfocitária , Transporte Proteico , Receptores de Antígenos de Linfócitos T alfa-beta/metabolismo , Riboflavina/metabolismo , Células THP-1
17.
Anticancer Res ; 40(4): 2043-2051, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32234895

RESUMO

BACKGROUND/AIM: While there has been a rapid development in genomic data mining approaches for T-cell receptor recombinations (TcR), less emphasis has been placed on B-cell receptor (BcR) recombinations. MATERIALS AND METHODS: We obtained lung cancer exome files from the cancer genome atlas (TCGA) and mined the files for TcR and BcR recombination reads. RESULTS: There was a robust detection of BcR light chain recombination reads in lung adenocarcinoma (TCGA-LUAD) samples, and there was a correlation between the detection of light chain recombination reads and a more favorable outcome. This result was supported by analyses of the expression of B-cell markers as indicated by LUAD RNASeq files. CONCLUSION: BcR and TcR recombination reads recovered from LUAD WXS files, either alone or in combination with the human leukocyte antigen (HLA) type, are likely to have prognostic value.


Assuntos
Adenocarcinoma de Pulmão/genética , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Receptores de Antígenos de Linfócitos T/genética , Recombinação Genética/genética , Adenocarcinoma de Pulmão/imunologia , Adenocarcinoma de Pulmão/patologia , Intervalo Livre de Doença , Exoma/genética , Feminino , Antígenos HLA/genética , Antígenos HLA/imunologia , Humanos , Estimativa de Kaplan-Meier , Masculino , Prognóstico , Interferência de RNA , Receptores de Antígenos de Linfócitos T/imunologia , Receptores de Antígenos de Linfócitos T alfa-beta/imunologia , Recombinação Genética/imunologia
18.
Sci Rep ; 10(1): 4472, 2020 03 11.
Artigo em Inglês | MEDLINE | ID: mdl-32161287

RESUMO

We investigated T-cell receptor variable ß chains binding to the superantigen staphylococcal enterotoxin C3 (SEC 3) with structure information in different stages of affinity maturation. Metadynamics in combination with molecular dynamics simulations allow to access the micro-to-millisecond timescale and reveal a strong effect of energetically significant mutations on the flexibility of the antigen-binding site. The observed changes in dynamics of the complementarity determining region (CDR) loops, especially the CDR 2, and HV 4 loop on this specific pathway of affinity maturation are reflected in their structural diversity, thermodynamics of conformations and kinetics of structural transitions. In addition, this affinity maturation pathway follows the concept of conformational selection, because even without the presence of the antigen the binding competent state is present in this pre-existing ensemble of conformations. In all stages of this affinity maturation process we observe a link between specificity and reduced flexibility.


Assuntos
Receptores de Antígenos de Linfócitos T alfa-beta/química , Receptores de Antígenos de Linfócitos T alfa-beta/metabolismo , Sítios de Ligação , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Ligação Proteica , Conformação Proteica , Domínios e Motivos de Interação entre Proteínas , Relação Estrutura-Atividade
19.
PLoS Comput Biol ; 16(3): e1007714, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32163410

RESUMO

Antigen recognition by T-cells is guided by the T-cell receptor (TCR) heterodimer formed by α and ß chains. A huge diversity of TCR sequences should be maintained by the immune system in order to be able to mount an effective response towards foreign pathogens, so, due to cooperative binding of α and ß chains to the pathogen, any constraints on chain pairing can have a profound effect on immune repertoire structure, diversity and antigen specificity. By integrating available structural data and paired chain sequencing results we were able to show that there are almost no constraints on pairing in TCRαß complexes, allowing naive T-cell repertoire to reach the highest possible diversity. Additional analysis reveals that the specific choice of contacting amino acids can still have a profound effect on complex conformation. Moreover, antigen-driven selection can distort the uniform landscape of chain pairing, while small, yet significant, differences in the pairing can be attributed to various specialized T-cell subsets such as MAIT and iNKT T-cells, as well as other TCR sets specific to certain antigens.


Assuntos
Receptores de Antígenos de Linfócitos T alfa-beta , Aminoácidos , Animais , Antígenos/química , Antígenos/metabolismo , Biologia Computacional , Bases de Dados de Proteínas , Humanos , Camundongos , Conformação Proteica , Receptores de Antígenos de Linfócitos T alfa-beta/química , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Receptores de Antígenos de Linfócitos T alfa-beta/metabolismo , Receptores de Antígenos de Linfócitos T alfa-beta/fisiologia
20.
Cancer Immunol Immunother ; 69(7): 1279-1292, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32185408

RESUMO

The presence of activated T cells in colorectal cancer tissues is a strong predictor of patient survival. Our previous studies have shown that regulatory T cells (Treg) are able to reduce T cell transendothelial migration in vitro and accumulation of effector T cells in intestinal tumors in vivo in the murine APCMin/+ model for microsatellite stable intestinal tumors. In this study, we investigated the effect of Treg depletion on the density and effector functions of different TCRαß+ and TCRγδ+ T cell populations in intestinal tumors. We used the APCMin/+\DEREG mouse model, which harbor a diphtheria toxin receptor under the control of the FOXP3 promoter, to deplete Treg in tumor bearing mice. We found that the density of conventional TCRαß+CD8αß+ T cells was significantly increased in Treg-depleted tumors in comparison with Treg-proficient tumors. Furthermore, TCRαß+CD8αß+ T cells showed increased proliferation and activation as well as increased Granzyme B and IFN-γ production in Treg-depleted tumors. In sharp contrast, the densities and effector functions of TCRαß+CD8αα+ T cells and TCRγδ+ T cells remained unchanged by Treg depletion. We also documented a distinct population of IL-17A+TNF+ TCRγδ+CD8- T cells in tumors, which were not affected by Treg depletion. We conclude that Treg depletion affects only conventional TCRαß+CD8αß+ T cells in intestinal tumors, while unconventional T cells and T cells in unaffected tissue are not altered. Immunotherapies aimed at depleting Treg from tumors may thus be a viable option for reinvigoration of conventional cytotoxic T cells with a Th1 cytokine profile.


Assuntos
Proteína da Polipose Adenomatosa do Colo/fisiologia , Antígenos CD8/imunologia , Linfócitos T CD8-Positivos/imunologia , Neoplasias Intestinais/imunologia , Linfócitos do Interstício Tumoral/imunologia , Receptores de Antígenos de Linfócitos T alfa-beta/imunologia , Linfócitos T Reguladores/imunologia , Animais , Antígenos CD8/metabolismo , Linfócitos T CD8-Positivos/metabolismo , Feminino , Humanos , Neoplasias Intestinais/metabolismo , Neoplasias Intestinais/patologia , Ativação Linfocitária , Depleção Linfocítica , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Receptores de Antígenos de Linfócitos T alfa-beta/metabolismo
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