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1.
Nat Immunol ; 21(5): 578-587, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32231298

RESUMO

The pool of beta cell-specific CD8+ T cells in type 1 diabetes (T1D) sustains an autoreactive potential despite having access to a constant source of antigen. To investigate the long-lived nature of these cells, we established a DNA methylation-based T cell 'multipotency index' and found that beta cell-specific CD8+ T cells retained a stem-like epigenetic multipotency score. Single-cell assay for transposase-accessible chromatin using sequencing confirmed the coexistence of naive and effector-associated epigenetic programs in individual beta cell-specific CD8+ T cells. Assessment of beta cell-specific CD8+ T cell anatomical distribution and the establishment of stem-associated epigenetic programs revealed that self-reactive CD8+ T cells isolated from murine lymphoid tissue retained developmentally plastic phenotypic and epigenetic profiles relative to the same cells isolated from the pancreas. Collectively, these data provide new insight into the longevity of beta cell-specific CD8+ T cell responses and document the use of this methylation-based multipotency index for investigating human and mouse CD8+ T cell differentiation.


Assuntos
Linfócitos T CD8-Positivos/fisiologia , Diabetes Mellitus Tipo 1/imunologia , Células Secretoras de Insulina/imunologia , Células-Tronco Pluripotentes/fisiologia , Adolescente , Adulto , Animais , Autoantígenos/imunologia , Plasticidade Celular , Células Cultivadas , Metilação de DNA , Epigênese Genética , Feminino , Citometria de Fluxo , Humanos , Memória Imunológica , Masculino , Camundongos , Análise de Célula Única , Adulto Jovem
2.
Cell ; 170(1): 142-157.e19, 2017 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-28648661

RESUMO

Immune-checkpoint-blockade (ICB)-mediated rejuvenation of exhausted T cells has emerged as a promising approach for treating various cancers and chronic infections. However, T cells that become fully exhausted during prolonged antigen exposure remain refractory to ICB-mediated rejuvenation. We report that blocking de novo DNA methylation in activated CD8 T cells allows them to retain their effector functions despite chronic stimulation during a persistent viral infection. Whole-genome bisulfite sequencing of antigen-specific murine CD8 T cells at the effector and exhaustion stages of an immune response identified progressively acquired heritable de novo methylation programs that restrict T cell expansion and clonal diversity during PD-1 blockade treatment. Moreover, these exhaustion-associated DNA-methylation programs were acquired in tumor-infiltrating PD-1hi CD8 T cells, and approaches to reverse these programs improved T cell responses and tumor control during ICB. These data establish de novo DNA-methylation programming as a regulator of T cell exhaustion and barrier of ICB-mediated T cell rejuvenation.


Assuntos
Linfócitos T CD8-Positivos/citologia , Epigênese Genética , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Adenocarcinoma/tratamento farmacológico , Animais , Linfócitos T CD8-Positivos/imunologia , Metilação de DNA , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Transplante de Neoplasias , Neoplasias da Próstata/tratamento farmacológico , Viroses/tratamento farmacológico
3.
Nature ; 552(7685): 362-367, 2017 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-29236685

RESUMO

The differentiation of human memory CD8 T cells is not well understood. Here we address this issue using the live yellow fever virus (YFV) vaccine, which induces long-term immunity in humans. We used in vivo deuterium labelling to mark CD8 T cells that proliferated in response to the virus and then assessed cellular turnover and longevity by quantifying deuterium dilution kinetics in YFV-specific CD8 T cells using mass spectrometry. This longitudinal analysis showed that the memory pool originates from CD8 T cells that divided extensively during the first two weeks after infection and is maintained by quiescent cells that divide less than once every year (doubling time of over 450 days). Although these long-lived YFV-specific memory CD8 T cells did not express effector molecules, their epigenetic landscape resembled that of effector CD8 T cells. This open chromatin profile at effector genes was maintained in memory CD8 T cells isolated even a decade after vaccination, indicating that these cells retain an epigenetic fingerprint of their effector history and remain poised to respond rapidly upon re-exposure to the pathogen.


Assuntos
Linfócitos T CD8-Positivos/citologia , Linfócitos T CD8-Positivos/imunologia , Diferenciação Celular/imunologia , Epigênese Genética , Memória Imunológica/imunologia , Vacina contra Febre Amarela/imunologia , Animais , Linfócitos T CD8-Positivos/metabolismo , Diferenciação Celular/genética , Proliferação de Células , Cromatina/genética , Cromatina/metabolismo , Metilação de DNA , Deutério , Perfilação da Expressão Gênica , Meia-Vida , Humanos , Memória Imunológica/genética , Contagem de Linfócitos , Camundongos , Técnica de Diluição de Radioisótopos , Transcrição Gênica , Febre Amarela/imunologia , Febre Amarela/virologia , Vírus da Febre Amarela/imunologia
4.
N Engl J Med ; 380(16): 1525-1534, 2019 04 18.
Artigo em Inglês | MEDLINE | ID: mdl-30995372

RESUMO

BACKGROUND: Allogeneic hematopoietic stem-cell transplantation for X-linked severe combined immunodeficiency (SCID-X1) often fails to reconstitute immunity associated with T cells, B cells, and natural killer (NK) cells when matched sibling donors are unavailable unless high-dose chemotherapy is given. In previous studies, autologous gene therapy with γ-retroviral vectors failed to reconstitute B-cell and NK-cell immunity and was complicated by vector-related leukemia. METHODS: We performed a dual-center, phase 1-2 safety and efficacy study of a lentiviral vector to transfer IL2RG complementary DNA to bone marrow stem cells after low-exposure, targeted busulfan conditioning in eight infants with newly diagnosed SCID-X1. RESULTS: Eight infants with SCID-X1 were followed for a median of 16.4 months. Bone marrow harvest, busulfan conditioning, and cell infusion had no unexpected side effects. In seven infants, the numbers of CD3+, CD4+, and naive CD4+ T cells and NK cells normalized by 3 to 4 months after infusion and were accompanied by vector marking in T cells, B cells, NK cells, myeloid cells, and bone marrow progenitors. The eighth infant had an insufficient T-cell count initially, but T cells developed in this infant after a boost of gene-corrected cells without busulfan conditioning. Previous infections cleared in all infants, and all continued to grow normally. IgM levels normalized in seven of the eight infants, of whom four discontinued intravenous immune globulin supplementation; three of these four infants had a response to vaccines. Vector insertion-site analysis was performed in seven infants and showed polyclonal patterns without clonal dominance in all seven. CONCLUSIONS: Lentiviral vector gene therapy combined with low-exposure, targeted busulfan conditioning in infants with newly diagnosed SCID-X1 had low-grade acute toxic effects and resulted in multilineage engraftment of transduced cells, reconstitution of functional T cells and B cells, and normalization of NK-cell counts during a median follow-up of 16 months. (Funded by the American Lebanese Syrian Associated Charities and others; LVXSCID-ND ClinicalTrials.gov number, NCT01512888.).


Assuntos
Bussulfano/administração & dosagem , Terapia Genética , Vetores Genéticos , Subunidade gama Comum de Receptores de Interleucina/genética , Lentivirus , Condicionamento Pré-Transplante , Doenças por Imunodeficiência Combinada Ligada ao Cromossomo X/terapia , Antígenos de Diferenciação de Linfócitos T/sangue , Linfócitos B/fisiologia , Transplante de Células-Tronco Hematopoéticas , Humanos , Imunoglobulina M/sangue , Lactente , Células Matadoras Naturais , Contagem de Linfócitos , Masculino , Linfócitos T , Doenças por Imunodeficiência Combinada Ligada ao Cromossomo X/genética , Doenças por Imunodeficiência Combinada Ligada ao Cromossomo X/imunologia
5.
Immunogenetics ; 74(1): 179-195, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35034136

RESUMO

Host immunity is classically divided into "innate" and "adaptive." While the former has always been regarded as the first, rapid, and antigen-nonspecific reaction to invading pathogens, the latter represents the more sophisticated and antigen-specific response that has the potential to persist and generate memory. Recent work however has challenged this dogma, where murine studies have successfully demonstrated the ability of innate immune cells (monocytes and macrophages) to acquire antigen-specific memory to allogeneic major histocompatibility complex (MHC) molecules. The immunoreceptors so far identified that mediate innate immune memory are the paired immunoglobulin-like receptors (PIRs) in mice, which are orthologous to human leukocyte immunoglobulin-like receptors (LILRs). These receptor families are mainly expressed by the myelomonocytic cell lineage, suggesting an important role in the innate immune response. In this review, we will discuss the role of immunoglobulin-like receptors in the development of innate immune memory across species.


Assuntos
Imunidade Inata , Memória Imunológica , Animais , Imunoglobulinas , Macrófagos , Camundongos , Monócitos
6.
Eur J Immunol ; 46(7): 1548-62, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27230488

RESUMO

T-cell-based immunological memory has the potential to provide the host with life-long protection against pathogen reexposure and thus offers tremendous promise for the design of vaccines targeting chronic infections or cancer. In order to exploit this potential in the design of new vaccines, it is necessary to understand how and when memory T cells acquire their poised effector potential, and moreover, how they maintain these properties during homeostatic proliferation. To gain insight into the persistent nature of memory T-cell functions, investigators have turned their attention to epigenetic mechanisms. Recent efforts have revealed that many of the properties acquired among memory T cells are coupled to stable changes in DNA methylation and histone modifications. Furthermore, it has recently been reported that the delineating features among memory T cells subsets are also linked to distinct epigenetic events, such as permissive and repressive histone modifications and DNA methylation programs, providing exciting new hypotheses regarding their cellular ancestry. Here, we review recent studies focused on epigenetic programs acquired during effector and memory T-cell differentiation and discuss how these data may shed new light on the developmental path for generating long-lived CD8(+) T-cell memory.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Epigênese Genética , Regulação da Expressão Gênica , Memória Imunológica/genética , Animais , Linfócitos T CD8-Positivos/citologia , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Reprogramação Celular/genética , Reprogramação Celular/imunologia , Metilação de DNA , Histonas/metabolismo , Humanos , Ativação Linfocitária/genética , Ativação Linfocitária/imunologia , Transcrição Gênica
7.
Immunol Cell Biol ; 95(10): 953-959, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28829048

RESUMO

Infection of the central nervous system (CNS) by murine polyomavirus (MuPyV), a persistent natural mouse pathogen, establishes brain-resident memory CD8 T cells (bTRM) that uniformly and chronically express programmed cell death protein 1 (PD-1) irrespective of the expression of αE integrin CD103, a TRM cell marker. In contrast, memory antiviral CD8 T cells in the spleen are PD-1-, despite viral loads being similar in both the brain and spleen during persistent infection. Repetitive antigen engagement is central to sustained PD-1 expression by T cells in chronic viral infections; however, recent evidence indicates that expression of inhibitory receptors, including PD-1, is part of the TRM differentiation program. Here we asked whether PD-1 expression by CD8 bTRM cells during persistent MuPyV encephalitis is antigen dependent. By transferring MuPyV-specific CD8 bTRM cells into the brains of naive mice and mice infected with cognate epitope-sufficient and -deficient MuPyVs, we demonstrate that antigen and inflammation are dispensable for PD-1 maintenance. In vitro and direct ex vivo analyses indicate that CD103- MuPyV-specific CD8 bTRM retain functional competence. We further show that the Pdcd-1 promoter of anti-MuPyV bTRM cells is epigenetically fixed in a demethylated state in the brain. In contrast, the PD-1 promoter of splenic antiviral memory CD8 T cells undergoes remethylation after being demethylated during acute infection. These data show that PD-1 expression is an intrinsic property of brain TRM cells in a persistent CNS viral infection.


Assuntos
Encéfalo/imunologia , Linfócitos T CD8-Positivos/imunologia , Infecções por Polyomavirus/imunologia , Polyomavirus/fisiologia , Receptor de Morte Celular Programada 1/metabolismo , Transferência Adotiva , Animais , Encéfalo/virologia , Linfócitos T CD8-Positivos/virologia , Diferenciação Celular , Células Cultivadas , Epigênese Genética , Epitopos de Linfócito T/imunologia , Feminino , Regulação da Expressão Gênica , Memória Imunológica , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptor de Morte Celular Programada 1/genética , Carga Viral
8.
J Immunol ; 191(11): 5764-76, 2013 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-24190658

RESUMO

We showed previously that nonmyeloablative total lymphoid irradiation/rabbit anti-thymocyte serum (TLI/ATS) conditioning facilitates potent donor-recipient immune tolerance following bone marrow transplantation (BMT) across MHC barriers via recipient invariant NKT (iNKT) cell-derived IL-4-dependent expansion of donor Foxp3(+) naturally occurring regulatory T cells (nTregs). In this study, we report a more specific mechanism. Wild-type (WT) BALB/c (H-2(d)) hosts were administered TLI/ATS and BMT from WT or STAT6(-/-) C57BL/6 (H-2(b)) donors. Following STAT6(-/-) BMT, donor nTregs demonstrated no loss of proliferation in vivo, indicating that an IL-4-responsive population in the recipient, rather than the donor, drives donor nTreg proliferation. In graft-versus-host disease (GVHD) target organs, three recipient CD11b(+) cell subsets (Gr-1(high)CD11c(-), Gr-1(int)CD11c(-), and Gr-1(low)CD11c(+)) were enriched early after TLI/ATS + BMT versus total body irradiation/ATS + BMT. Gr-1(low)CD11c(+) cells induced potent H-2K(b+)CD4(+)Foxp3(+) nTreg proliferation in vitro in 72-h MLRs. Gr-1(low)CD11c(+) cells were reduced significantly in STAT6(-/-) and iNKT cell-deficient Jα18(-/-) BALB/c recipients after TLI/ATS + BMT. Depletion of CD11b(+) cells resulted in severe acute GVHD, and adoptive transfer of WT Gr-1(low)CD11c(+) cells to Jα18(-/-) BALB/c recipients of TLI/ATS + BMT restored day-6 donor Foxp3(+) nTreg proliferation and protection from CD8 effector T cell-mediated GVHD. Blockade of programmed death ligand 1 and 2, but not CD40, TGF-ß signaling, arginase 1, or iNOS, inhibited nTreg proliferation in cocultures of recipient-derived Gr-1(low)CD11c(+) cells with donor nTregs. Through iNKT-dependent Th2 polarization, myeloid-derived immunomodulatory dendritic cells are expanded after nonmyeloablative TLI/ATS conditioning and allogeneic BMT, induce PD-1 ligand-dependent donor nTreg proliferation, and maintain potent graft-versus-host immune tolerance.


Assuntos
Transplante de Medula Óssea , Células Dendríticas/imunologia , Fatores de Transcrição Forkhead/metabolismo , Células Mieloides/imunologia , Linfócitos T Reguladores/imunologia , Tolerância ao Transplante/imunologia , Animais , Antígeno CD11c , Antígenos CD4/metabolismo , Proliferação de Células , Fatores de Transcrição Forkhead/genética , Imunomodulação , Irradiação Linfática , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Receptor de Morte Celular Programada 1/metabolismo , Fator de Transcrição STAT6/genética , Doadores de Tecidos
9.
Front Immunol ; 13: 1001129, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36172358

RESUMO

Cytotoxic CD8 T cells (CTLs) are classically described as the "serial killers" of the immune system, where they play a pivotal role in protective immunity against a wide spectrum of pathogens and tumors. Ironically, they are critical drivers of transplant rejection and autoimmune diseases, a scenario very similar to the famous novel "The strange case of Dr. Jekyll and Mr. Hyde". Until recently, it has not been well-appreciated whether CTLs can also acquire non-cytotoxic functions in health and disease. Several investigations into this question revealed their non-cytotoxic functions through interactions with various immune and non-immune cells. In this review, we will establish a new classification for CD8 T cell functions including cytotoxic and non-cytotoxic. Further, we will discuss this novel concept and speculate on how these functions could contribute to homeostasis of the immune system as well as immunological responses in transplantation, cancer, and autoimmune diseases.


Assuntos
Doenças Autoimunes , Neoplasias , Linfócitos T CD8-Positivos , Humanos , Linfócitos T Citotóxicos
10.
Commun Biol ; 5(1): 634, 2022 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-35768564

RESUMO

T cells are endowed with the capacity to sense their environment including other T cells around them. They do so to set their numbers and activation thresholds. This form of regulation has been well-studied within a given T cell population - i.e., within the naïve or memory pool; however, less is known about the cross-talk between T cell subsets. Here, we tested whether memory T cells interact with and influence surrounding naïve T cells. We report that human naïve CD8 T cells (TN) undergo phenotypic and transcriptional changes in the presence of autologous activated-memory CD8 T cells (TMem). Following in vitro co-culture with activated central memory cells (TCM), ~3% of the TN acquired activation/memory canonical markers (CD45RO and CD95) in an MHC-I dependent-fashion. Using scRNA-seq, we also observed that ~3% of the TN acquired an activated/memory signature, while ~84% developed a unique activated transcriptional profile hybrid between naïve and activated memory. Pseudotime trajectory analysis provided further evidence that TN with an activated/memory or hybrid phenotype were derived from TN. Our data reveal a non-cytotoxic function of TMem with potential to activate autologous TN into the activated/memory pool. These findings may have implications for host-protection and autoimmunity that arises after vaccination, infection or transplantation.


Assuntos
Memória Imunológica , Células T de Memória , Linfócitos T CD8-Positivos , Humanos , Subpopulações de Linfócitos T
11.
J Clin Invest ; 131(21)2021 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-34720090

RESUMO

Direct allorecognition, the ability of host T cells to recognize intact allogeneic MHC molecules on transplanted tissues, is often assumed to be less dependent on the peptide bound to the MHC molecule than are other antigen recognition pathways. In this issue of the JCI, Son et al. provide unequivocal, in vivo evidence that direct allorecognition depends on the self-peptides bound to the non-self MHC molecule. The authors demonstrate that the induction of allospecific tolerance required the presentation of self-peptides by the non-self MHC molecule, and that only a handful of these peptides accounted for a sizeable proportion of the immunogenicity of the MHC antigen. These are important findings for transplant immunologists because they provide molecular insights into the biology of direct allorecognition, the prime driver of the alloimmune response to MHC-mismatched grafts, and much-needed tools, peptide-MHC multimers, to track and study polyclonal alloreactive T cells.


Assuntos
Isoantígenos , Linfócitos T , Tolerância Imunológica , Peptídeos , Linfócitos T/imunologia
12.
Cell Rep ; 37(2): 109796, 2021 10 12.
Artigo em Inglês | MEDLINE | ID: mdl-34644568

RESUMO

To gain insight into the signaling determinants of effector-associated DNA methylation programming among CD8 T cells, we explore the role of interleukin (IL)-12 in the imprinting of IFNg expression during CD8 T cell priming. We observe that anti-CD3/CD28-mediated stimulation of human naive CD8 T cells is not sufficient to induce substantial demethylation of the IFNg promoter. However, anti-CD3/CD28 stimulation in the presence of the inflammatory cytokine, IL-12, results in stable demethylation of the IFNg locus that is commensurate with IFNg expression. IL-12-associated demethylation of the IFNg locus is coupled to cell division through TET2-dependent demethylation in an ex vivo human chimeric antigen receptor T cell model system and an in vivo immunologically competent murine system. Collectively, these data illustrate that IL-12 signaling promotes TET2-mediated effector DNA demethylation programming in CD8 T cells and serve as proof of concept that cytokines can guide induction of epigenetically regulated traits for T cell-based immunotherapies.


Assuntos
Linfócitos T CD8-Positivos/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Metilação de DNA/efeitos dos fármacos , Proteínas de Ligação a DNA/metabolismo , Dioxigenases/metabolismo , Interferon gama/metabolismo , Interleucina-12/farmacologia , Coriomeningite Linfocítica/enzimologia , Células T de Memória/efeitos dos fármacos , Animais , Linfócitos T CD8-Positivos/enzimologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/virologia , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Proteínas de Ligação a DNA/genética , Dioxigenases/genética , Modelos Animais de Doenças , Humanos , Memória Imunológica/efeitos dos fármacos , Interferon gama/genética , Coriomeningite Linfocítica/genética , Coriomeningite Linfocítica/imunologia , Vírus da Coriomeningite Linfocítica/imunologia , Vírus da Coriomeningite Linfocítica/patogenicidade , Células T de Memória/enzimologia , Células T de Memória/imunologia , Células T de Memória/virologia , Camundongos Endogâmicos C57BL , Camundongos Knockout , Estudo de Prova de Conceito , Transdução de Sinais
13.
PLoS Pathog ; 4(4): e1000042, 2008 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-18421376

RESUMO

Striking individual differences in severity of group A streptococcal (GAS) sepsis have been noted, even among patients infected with the same bacterial strain. We had provided evidence that HLA class II allelic variation contributes significantly to differences in systemic disease severity by modulating host responses to streptococcal superantigens. Inasmuch as the bacteria produce additional virulence factors that participate in the pathogenesis of this complex disease, we sought to identify additional gene networks modulating GAS sepsis. Accordingly, we applied a systems genetics approach using a panel of advanced recombinant inbred mice. By analyzing disease phenotypes in the context of mice genotypes we identified a highly significant quantitative trait locus (QTL) on Chromosome 2 between 22 and 34 Mb that strongly predicts disease severity, accounting for 25%-30% of variance. This QTL harbors several polymorphic genes known to regulate immune responses to bacterial infections. We evaluated candidate genes within this QTL using multiple parameters that included linkage, gene ontology, variation in gene expression, cocitation networks, and biological relevance, and identified interleukin1 alpha and prostaglandin E synthases pathways as key networks involved in modulating GAS sepsis severity. The association of GAS sepsis with multiple pathways underscores the complexity of traits modulating GAS sepsis and provides a powerful approach for analyzing interactive traits affecting outcomes of other infectious diseases.


Assuntos
Mapeamento Cromossômico/métodos , Predisposição Genética para Doença , Sepse/genética , Infecções Estreptocócicas/genética , Streptococcus pyogenes/patogenicidade , Animais , Bacteriemia , Feminino , Regulação Bacteriana da Expressão Gênica , Genômica , Genótipo , Longevidade , Masculino , Camundongos , Camundongos Endogâmicos , Camundongos Transgênicos , Locos de Características Quantitativas , Recombinação Genética , Sepse/microbiologia , Infecções Estreptocócicas/microbiologia , Streptococcus pyogenes/fisiologia
14.
Sci Transl Med ; 11(498)2019 06 26.
Artigo em Inglês | MEDLINE | ID: mdl-31243155

RESUMO

Cancer arises from the accumulation of genetic alterations, which can lead to the production of mutant proteins not expressed by normal cells. These mutant proteins can be processed and presented on the cell surface by major histocompatibility complex molecules as neoepitopes, allowing CD8+ T cells to mount responses against them. For solid tumors, only an average 2% of neoepitopes predicted by algorithms have detectable endogenous antitumor T cell responses. This suggests that low mutation burden tumors, which include many pediatric tumors, are poorly immunogenic. Here, we report that pediatric patients with acute lymphoblastic leukemia (ALL) have tumor-associated neoepitope-specific CD8+ T cells, responding to 86% of tested neoantigens and recognizing 68% of the tested neoepitopes. These responses include a public neoantigen from the ETV6-RUNX1 fusion that is targeted in seven of nine tested patients. We characterized phenotypic and transcriptional profiles of CD8+ tumor-infiltrating lymphocytes (TILs) at the single-cell level and found a heterogeneous population that included highly functional effectors. Moreover, we observed immunodominance hierarchies among the CD8+ TILs restricted to one or two putative neoepitopes. Our results indicate that robust antitumor immune responses are induced in pediatric ALL despite their low mutation burdens and emphasize the importance of immunodominance in shaping cellular immune responses. Furthermore, these data suggest that pediatric cancers may be amenable to immunotherapies aimed at enhancing immune recognition of tumor-specific neoantigens.


Assuntos
Antígenos de Neoplasias/imunologia , Linfócitos T CD8-Positivos/imunologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/imunologia , Apresentação de Antígeno/imunologia , Criança , Heterogeneidade Genética , Humanos , Epitopos Imunodominantes/imunologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Reprodutibilidade dos Testes , Transcrição Gênica
15.
Front Immunol ; 9: 6, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29403491

RESUMO

Memory CD8 T cells have a unique ability to provide lifelong immunity against pathogens containing their cognate epitope. Because of their ability to provide lifelong protection, the generation of memory T cells is now a major focus for current vaccination or adoptive cell therapy approaches to treat chronic viral infections and cancer. It is now clear that maintenance of memory CD8 T cells occurs through a process of antigen-independent homeostatic proliferation, which is regulated in part by the gamma chain cytokines IL-7 and IL-15. Here, we will describe the role of these cytokines in the survival and self-renewal of memory CD8 T cells. Further, we will describe the role of epigenetics in the maintenance of acquired functions among memory CD8 T cells during homeostatic proliferation.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Epigênese Genética/genética , Regulação da Expressão Gênica/genética , Expressão Gênica/imunologia , Homeostase/imunologia , Memória Imunológica/imunologia , Animais , Humanos , Interleucina-15/imunologia , Interleucina-7/imunologia , Ativação Linfocitária/imunologia , Camundongos , Transdução de Sinais/imunologia
16.
Leukemia ; 32(5): 1157-1167, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29479065

RESUMO

In vivo persistence of chimeric antigen receptor (CAR)-modified T cells correlates with therapeutic efficacy, yet CAR-specific factors that support persistence are not well resolved. Using a CD33-specific CAR in an acute myeloid leukemia (AML) model, we show how CAR expression alters T cell differentiation in a ligand independent manner. Ex vivo expanded CAR-T cells demonstrated decreased naïve and stem memory populations and increased effector subsets relative to vector-transduced control cells. This was associated with reduced in vivo persistence. Decreased persistence was not due to specificity or tumor presence, but to pre-transfer tonic signaling through the CAR CD3ζ ITAMs. We identified activation of the PI3K pathway in CD33 CAR-T cells as responsible. Treatment with a PI3K inhibitor modulated the differentiation program of CAR-T cells, preserved a less differentiated state without affecting T cell expansion, and improved in vivo persistence and reduced tumor burden. These results resolve mechanisms by which tonic signaling of CAR-T cells modulates their fate, and identifies a novel pharmacologic approach to enhance the durability of CAR-T cells for immunotherapy.


Assuntos
Imunoterapia Adotiva/métodos , Leucemia Mieloide Aguda/terapia , Fosfatidilinositol 3-Quinases/metabolismo , Receptores de Antígenos Quiméricos/uso terapêutico , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Humanos , Ativação Linfocitária/efeitos dos fármacos , Inibidores de Fosfoinositídeo-3 Quinase , Lectina 3 Semelhante a Ig de Ligação ao Ácido Siálico/farmacologia , Lectina 3 Semelhante a Ig de Ligação ao Ácido Siálico/uso terapêutico , Linfócitos T , Carga Tumoral/efeitos dos fármacos
17.
Bio Protoc ; 7(22)2017 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-29226183

RESUMO

Long-lived T-cell-mediated immunity requires persistence of memory T cells in an antigen-free environment while also maintaining a heightened capacity to recall effector functions. Such antigen-independent homeostatic proliferation is mediated in part by the common gamma-chain cytokines IL-7 and IL-15. To further explore the mechanisms governing maintenance of effector functions in long-lived memory T cells during antigen-independent proliferation, human naïve and memory CD8 T cells can be sorted from peripheral blood mononuclear cells (PBMCs), labeled with the proliferation-tracking dye carboxyfluorescein succinimidyl ester (CFSE), and then purified based on their levels of cell division. This allows investigators to assess differences in the desired molecular target in cells that have undergone cytokine-driven proliferation. We provide here a protocol for assessing epigenetic programs in divided and undivided human naïve and memory CD8 T cells following 7 days in culture with IL-7 and IL-15 to illustrate how this approach can shed light on the mechanism(s) that governs the preservation of effector functions during homeostasis of long-lived memory CD8 T cells.

18.
J Exp Med ; 214(6): 1593-1606, 2017 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-28490440

RESUMO

Antigen-independent homeostasis of memory CD8 T cells is vital for sustaining long-lived T cell-mediated immunity. In this study, we report that maintenance of human memory CD8 T cell effector potential during in vitro and in vivo homeostatic proliferation is coupled to preservation of acquired DNA methylation programs. Whole-genome bisulfite sequencing of primary human naive, short-lived effector memory (TEM), and longer-lived central memory (TCM) and stem cell memory (TSCM) CD8 T cells identified effector molecules with demethylated promoters and poised for expression. Effector-loci demethylation was heritably preserved during IL-7- and IL-15-mediated in vitro cell proliferation. Conversely, cytokine-driven proliferation of TCM and TSCM memory cells resulted in phenotypic conversion into TEM cells and was coupled to increased methylation of the CCR7 and Tcf7 loci. Furthermore, haploidentical donor memory CD8 T cells undergoing in vivo proliferation in lymphodepleted recipients also maintained their effector-associated demethylated status but acquired TEM-associated programs. These data demonstrate that effector-associated epigenetic programs are preserved during cytokine-driven subset interconversion of human memory CD8 T cells.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Epigênese Genética , Homeostase/genética , Homeostase/imunologia , Memória Imunológica/genética , Transferência Adotiva , Linfócitos T CD8-Positivos/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/imunologia , Proliferação de Células/efeitos dos fármacos , Reprogramação Celular/efeitos dos fármacos , Reprogramação Celular/genética , Citocinas/farmacologia , Metilação de DNA/efeitos dos fármacos , Metilação de DNA/genética , Epigênese Genética/efeitos dos fármacos , Loci Gênicos , Genoma Humano , Transplante de Células-Tronco Hematopoéticas , Fator 1-alfa Nuclear de Hepatócito/metabolismo , Homeostase/efeitos dos fármacos , Humanos , Hospedeiro Imunocomprometido , Memória Imunológica/efeitos dos fármacos , Subpopulações de Linfócitos/efeitos dos fármacos , Subpopulações de Linfócitos/imunologia , Fenótipo , Receptores CCR7/metabolismo , Doadores de Tecidos
19.
J Cancer Sci Ther ; 6(9): 370-377, 2014 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-25574358

RESUMO

Glioma is a brain tumor that arises from glial cells or glial progenitor cells, and represents 80% of malignant brain tumor incidence in the United States. Glioblastoma multiforme (GBM) is the most aggressive primary brain tumor malignancy with fewer than 8% of patients with GBM surviving for more than 3 years. Over the past 10 years, despite improvement in diagnosis and therapies for cancer, the survival rate for high-grade glioma patients remains dismal. The main focus of our research is to identify potent novel antiglioma small molecules. We previously showed that EDL-360, a tetrahydroisoquinoline (THIQ) analog, as being highly cytotoxic to human glioma cell cultures. Here we show that EDL-360 significantly induced apoptosis in human glioma cell lines (U87 and LN18). However, in normal astrocytic cells, EDL-360 induced a modest G0/G1 cell cycle arrest but did not induce apoptosis. In an attempt to enhance EDL-360 induced cell death, we tested simultaneous treatment with EDL-360 and embelin (an inhibitor of the anti-apoptotic protein, XIAP). We found that, glioma cells had significant lower viability when EDL-360 and embelin were used in combination when compared to EDL-360 alone. We also used combination treatment of EDL-360 with decylubiquinone (dUb), a caspase-9 inhibitor, and found that the combination treatment induced a significant cell death when compared to treatment with EDL-360 alone. This is the first report that suggests that dUb has anticancer activity, and perhaps acts as a XIAP inhibitor. Finally, our in vivo data showed that EDL-360 treatment induced a partial regression in glioma tumorigenesis and induced cell death in the treated tumors as shown by H&E staining. Taken together these data suggests that EDL-360 has a potential therapeutic application for treating glioma, especially when combined with XIAP inhibitors.

20.
Future Microbiol ; 8(9): 1129-1146, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24020741

RESUMO

Chlamydia trachomatis infections are a global health problem. This obligate intracellular bacterial pathogen comprises lymphogranuloma venereum (L1-L3), ocular (A-C) and genital (D-K) serovars. Although genetically similar, each serovar group differs in disease severity and tissue tropism through mechanisms that are not well understood. It is clear that host genetic differences also play a role in chlamydial disease outcome and key host polymorphisms are beginning to emerge from both human and experimental animal studies. In this review, we will highlight pathogen and host genes that link genetic diversity, disease severity and tissue tropism. We will also use this information to provide new insights that may be helpful in developing improved management strategies for these important pathogens.


Assuntos
Infecções por Chlamydia/microbiologia , Infecções por Chlamydia/patologia , Chlamydia trachomatis/classificação , Chlamydia trachomatis/genética , Variação Genética , Interações Hospedeiro-Patógeno , Animais , Modelos Animais de Doenças , Humanos
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