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1.
Proc Natl Acad Sci U S A ; 116(28): 14113-14118, 2019 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-31227606

RESUMO

We have recently defined a novel population of PD-1 (programmed cell death 1)+ TCF1 (T cell factor 1)+ virus-specific CD8 T cells that function as resource cells during chronic LCMV infection and provide the proliferative burst seen after PD-1 blockade. Such CD8 T cells have been found in other chronic infections and also in cancer in mice and humans. These CD8 T cells exhibit stem-like properties undergoing self-renewal and also differentiating into the terminally exhausted CD8 T cells. Here we compared the epigenetic signature of stem-like CD8 T cells with exhausted CD8 T cells. ATAC-seq analysis showed that stem-like CD8 T cells had a unique signature implicating activity of HMG (TCF) and RHD (NF-κB) transcription factor family members in contrast to higher accessibility to ETS and RUNX motifs in exhausted CD8 T cells. In addition, regulatory regions of the transcription factors Tcf7 and Id3 were more accessible in stem-like cells whereas Prdm1 and Id2 were more accessible in exhausted CD8 T cells. We also compared the epigenetic signatures of the 2 CD8 T cell subsets from chronically infected mice with effector and memory CD8 T cells generated after an acute LCMV infection. Both CD8 T cell subsets generated during chronic infection were strikingly different from CD8 T cell subsets from acute infection. Interestingly, the stem-like CD8 T cell subset from chronic infection, despite sharing key functional properties with memory CD8 T cells, had a very distinct epigenetic program. These results show that the chronic stem-like CD8 T cell program represents a specific adaptation of the T cell response to persistent antigenic stimulation.

2.
Immunity ; 50(4): 832-850, 2019 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-30995502

RESUMO

The common cytokine receptor γ chain, γc, is a component of the receptors for interleukin-2 (IL-2), IL-4, IL-7, IL-9, IL-15, and IL-21. Mutation of the gene encoding γc results in X-linked severe combined immunodeficiency in humans, and γc family cytokines collectively regulate development, proliferation, survival, and differentiation of immune cells. Here, we review the basic biology of these cytokines, highlighting mechanisms of signaling and gene regulation that have provided insights for immunodeficiency, autoimmunity, allergic diseases, and cancer. Moreover, we discuss how studies of this family stimulated the development of JAK3 inhibitors and present an overview of current strategies targeting these pathways in the clinic, including novel antibodies, antagonists, and partial agonists. The diverse roles of these cytokines on a range of immune cells have important therapeutic implications.


Assuntos
Citocinas/classificação , Subunidade gama Comum de Receptores de Interleucina/genética , Família Multigênica/imunologia , Animais , Doenças Autoimunes/genética , Doenças Autoimunes/imunologia , Citocinas/genética , Citocinas/imunologia , Evolução Molecular , Regulação da Expressão Gênica , Terapia Genética , Humanos , Síndromes de Imunodeficiência/imunologia , Síndromes de Imunodeficiência/terapia , Janus Quinase 3/antagonistas & inibidores , Janus Quinases/antagonistas & inibidores , Janus Quinases/fisiologia , Subpopulações de Linfócitos/imunologia , Camundongos , Terapia de Alvo Molecular , Família Multigênica/genética , Neoplasias/genética , Neoplasias/imunologia , Subunidades Proteicas , Fatores de Transcrição STAT/fisiologia , Transdução de Sinais , Pesquisa Médica Translacional , Doenças por Imunodeficiência Combinada Ligada ao Cromossomo X/genética , Doenças por Imunodeficiência Combinada Ligada ao Cromossomo X/imunologia , Doenças por Imunodeficiência Combinada Ligada ao Cromossomo X/terapia
3.
Proc Natl Acad Sci U S A ; 116(19): 9511-9520, 2019 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-31000603

RESUMO

The IRF and Ets families of transcription factors regulate the expression of a range of genes involved in immune cell development and function. However, the understanding of the molecular mechanisms of each family member has been limited due to their redundancy and broad effects on multiple lineages of cells. Here, we report that double deletion of floxed Irf8 and Spi1 (encoding PU.1) by Mb1-Cre (designated DKO mice) in the B cell lineage resulted in severe defects in the development of follicular and germinal center (GC) B cells. Class-switch recombination and antibody affinity maturation were also compromised in DKO mice. RNA-seq (sequencing) and ChIP-seq analyses revealed distinct IRF8 and PU.1 target genes in follicular and activated B cells. DKO B cells had diminished expression of target genes vital for maintaining follicular B cell identity and GC development. Moreover, our findings reveal that expression of B-cell lymphoma protein 6 (BCL6), which is critical for development of germinal center B cells, is dependent on IRF8 and PU.1 in vivo, providing a mechanism for the critical role for IRF8 and PU.1 in the development of GC B cells.

4.
Annu Rev Immunol ; 37: 295-324, 2019 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-30649989

RESUMO

Cytokines are secreted or otherwise released polypeptide factors that exert autocrine and/or paracrine actions, with most cytokines acting in the immune and/or hematopoietic system. They are typically pleiotropic, controlling development, cell growth, survival, and/or differentiation. Correspondingly, cytokines are clinically important, and augmenting or attenuating cytokine signals can have deleterious or therapeutic effects. Besides physiological fine-tuning of cytokine signals, altering the nature or potency of the signal can be important in pathophysiological responses and can also provide novel therapeutic approaches. Here, we give an overview of cytokines, their signaling and actions, and the physiological mechanisms and pharmacologic strategies to fine-tune their actions. In particular, the differential utilization of STAT proteins by a single cytokine or by different cytokines and STAT dimerization versus tetramerization are physiological mechanisms of fine-tuning, whereas anticytokine and anticytokine receptor antibodies and cytokines with altered activities, including cytokine superagonists, partial agonists, and antagonists, represent new ways of fine-tuning cytokine signals.

5.
Sci Immunol ; 3(24)2018 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-29907691

RESUMO

Heterozygosity for human signal transducer and activator of transcription 3 (STAT3) dominant-negative (DN) mutations underlies an autosomal dominant form of hyper-immunoglobulin E syndrome (HIES). We describe patients with an autosomal recessive form of HIES due to loss-of-function mutations of a previously uncharacterized gene, ZNF341 ZNF341 is a transcription factor that resides in the nucleus, where it binds a specific DNA motif present in various genes, including the STAT3 promoter. The patients' cells have low basal levels of STAT3 mRNA and protein. The autoinduction of STAT3 production, activation, and function by STAT3-activating cytokines is strongly impaired. Like patients with STAT3 DN mutations, ZNF341-deficient patients lack T helper 17 (TH17) cells, have an excess of TH2 cells, and have low memory B cells due to the tight dependence of STAT3 activity on ZNF341 in lymphocytes. Their milder extra-hematopoietic manifestations and stronger inflammatory responses reflect the lower ZNF341 dependence of STAT3 activity in other cell types. Human ZNF341 is essential for the STAT3 transcription-dependent autoinduction and sustained activity of STAT3.

6.
Artigo em Inglês | MEDLINE | ID: mdl-29038115

RESUMO

Interleukin (IL)-2, IL-4, IL-7, IL-9, IL-15, and IL-21 form a family of cytokines based on their sharing the common cytokine receptor γ chain (γc), which was originally discovered as the third receptor component of the IL-2 receptor, IL-2Rγ. The IL2RG gene is located on the X chromosome and is mutated in humans with X-linked severe combined immunodeficiency (XSCID). The breadth of the defects in XSCID could not be explained solely by defects in IL-2 signaling, and it is now clear that γc is a shared receptor component of the six cytokines noted above, making XSCID a disease of defective cytokine signaling. Janus kinase (JAK)3 associates with γc, and JAK3-deficient SCID phenocopies XSCID, findings that served to stimulate the development of JAK3 inhibitors as immunosuppressants. γc family cytokines collectively control broad aspects of lymphocyte development, growth, differentiation, and survival, and these cytokines are clinically important, related to allergic and autoimmune diseases and cancer as well as immunodeficiency. In this review, we discuss the actions of these cytokines, their critical biological roles and signaling pathways, focusing mainly on JAK/STAT (signal transducers and activators of transcription) signaling, and how this information is now being used in clinical therapeutic efforts.

7.
Nat Commun ; 8(1): 1320, 2017 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-29105654

RESUMO

Interleukin-15 (IL-15) is essential for the development and maintenance of natural killer (NK) cells. IL-15 activates STAT5 proteins, which can form dimers or tetramers. We previously found that NK cell numbers are decreased in Stat5a-Stat5b tetramer-deficient double knockin (DKI) mice, but the mechanism was not investigated. Here we show that STAT5 dimers are sufficient for NK cell development, whereas STAT5 tetramers mediate NK cell maturation and the expression of maturation-associated genes. Unlike the defective proliferation of Stat5 DKI CD8+ T cells, Stat5 DKI NK cells have normal proliferation to IL-15 but are susceptible to death upon cytokine withdrawal, with lower Bcl2 and increased active caspases. These findings underscore the importance of STAT5 tetramers in maintaining NK cell homoeostasis. Moreover, defective STAT5 tetramer formation could represent a cause of NK cell immunodeficiency, and interrupting STAT5 tetramer formation might serve to control NK leukaemia.


Assuntos
Células Matadoras Naturais/imunologia , Fator de Transcrição STAT5/imunologia , Animais , Diferenciação Celular/imunologia , Proliferação de Células , Sobrevivência Celular/imunologia , Citocinas/imunologia , Feminino , Expressão Gênica , Técnicas de Introdução de Genes , Homeostase , Células Matadoras Naturais/citologia , Masculino , Camundongos , Camundongos Transgênicos , Modelos Imunológicos , Estrutura Quaternária de Proteína , Proteínas Proto-Oncogênicas c-bcl-2/imunologia , Fator de Transcrição STAT5/química , Fator de Transcrição STAT5/genética
8.
Proc Natl Acad Sci U S A ; 114(46): 12111-12119, 2017 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-29078395

RESUMO

Cytokines critically control immune responses, but how regulatory programs are altered to allow T cells to differentially respond to distinct cytokine stimuli remains poorly understood. Here, we have globally analyzed enhancer elements bound by IL-2-activated STAT5 and IL-21-activated STAT3 in T cells and identified Il2ra as the top-ranked gene regulated by an IL-2-activated STAT5-bound superenhancer and one of the top genes regulated by STAT3-bound superenhancers. Moreover, we found that STAT5 binding was rapidly superenriched at genes highly induced by IL-2 and that IL-2-activated STAT5 binding induces new and augmented chromatin interactions within superenhancer-containing genes. Based on chromatin interaction analysis by paired-end tag (ChIA-PET) sequencing data, we used CRISPR-Cas9 gene editing to target three of the STAT5 binding sites within the Il2ra superenhancer in mice. Each mutation decreased STAT5 binding and altered IL-2-induced Il2ra gene expression, revealing that individual elements within the superenhancer were not functionally redundant and that all were required for normal gene expression. Thus, we demonstrate cooperative utilization of superenhancer elements to optimize gene expression and show that STAT5 mediates IL-2-induced chromatin looping at superenhancers to preferentially regulate highly inducible genes, thereby providing new insights into the mechanisms underlying cytokine-dependent superenhancer function.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Elementos Facilitadores Genéticos , Interleucina-2/genética , Receptores de Interleucina-2/imunologia , Fator de Transcrição STAT5/imunologia , Animais , Sítios de Ligação , Linfócitos T CD8-Positivos/citologia , Sistemas CRISPR-Cas , Cromatina/química , Cromatina/imunologia , Edição de Genes , Regulação da Expressão Gênica , Genes Reporter , Loci Gênicos , Humanos , Interleucina-2/imunologia , Interleucinas/genética , Interleucinas/imunologia , Luciferases/genética , Luciferases/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Mutação , Ligação Proteica , Receptores de Interleucina-2/genética , Fator de Transcrição STAT5/genética , Transdução de Sinais , Transcrição Genética
9.
PLoS One ; 11(8): e0160339, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27537504

RESUMO

STAT proteins bind DNA as dimers and tetramers to control cellular development, differentiation, survival, and expansion. The tetramer binding sites are comprised of two dimer-binding sites repeated in tandem. The genome-wide distribution of the spacings between the dimer binding sites shows a distinctive, non-random pattern. Here, we report on estimating the feasibility of building possible molecular models of STAT5A tetramers bound to a DNA double helix with all possible spacings between the dimer binding sites. We found that the calculated feasibility estimates correlated well with the experimentally measured frequency of tetramer-binding sites. This suggests that the feasibility of forming the tetramer complex was a major factor in the evolution of this DNA sequence variation.


Assuntos
Proteínas de Ligação a DNA/genética , Fator de Transcrição STAT5/genética , Animais , Sítios de Ligação/genética , Proteínas de Ligação a DNA/química , Humanos , Camundongos , Modelos Moleculares , Fator de Transcrição STAT5/química , Proteínas Supressoras de Tumor/química , Proteínas Supressoras de Tumor/genética
11.
Nat Immunol ; 17(4): 422-32, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26950239

RESUMO

T cell responses are guided by cytokines that induce transcriptional regulators, which ultimately control differentiation of effector and memory T cells. However, it is unknown how the activities of these molecular regulators are coordinated and integrated during the differentiation process. Using genetic approaches and transcriptional profiling of antigen-specific CD8(+) T cells, we reveal a common program of effector differentiation that is regulated by IL-2 and IL-12 signaling and the combined activities of the transcriptional regulators Blimp-1 and T-bet. The loss of both T-bet and Blimp-1 leads to abrogated cytotoxic function and ectopic IL-17 production in CD8(+) T cells. Overall, our data reveal two major overlapping pathways of effector differentiation governed by the availability of Blimp-1 and T-bet and suggest a model for cytokine-induced transcriptional changes that combine, quantitatively and qualitatively, to promote robust effector CD8(+) T cell differentiation.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Diferenciação Celular/imunologia , Interleucina-12/imunologia , Interleucina-2/imunologia , Proteínas com Domínio T/imunologia , Fatores de Transcrição/imunologia , Animais , Infecções por Arenaviridae/imunologia , Imunoprecipitação da Cromatina , Citocinas/imunologia , Citometria de Fluxo , Perfilação da Expressão Gênica , Vírus da Influenza A Subtipo H1N1 , Interleucina-17/imunologia , Vírus da Coriomeningite Linfocítica , Camundongos , Infecções por Orthomyxoviridae/imunologia , Fator 1 de Ligação ao Domínio I Regulador Positivo , Reação em Cadeia da Polimerase em Tempo Real , Fator de Transcrição STAT4/imunologia , Fator de Transcrição STAT5/imunologia , Análise de Sequência de RNA , Transdução de Sinais
12.
Mol Syst Biol ; 11(8): 826, 2015 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-26253570

RESUMO

Crucial parts of the genome including genes encoding microRNAs and noncoding RNAs went unnoticed for years, and even now, despite extensive annotation and assembly of the human genome, RNA-sequencing continues to yield millions of unmappable and thus uncharacterized reads. Here, we examined > 300 billion reads from 536 normal donors and 1,873 patients encompassing 21 cancer types, identified ~300 million such uncharacterized reads, and using a distinctive approach de novo assembled 2,550 novel human transcripts, which mainly represent long noncoding RNAs. Of these, 230 exhibited relatively specific expression or non-expression in certain cancer types, making them potential markers for those cancers, whereas 183 exhibited tissue specificity. Moreover, we used lentiviral-mediated expression of three selected transcripts that had higher expression in normal than in cancer patients and found that each inhibited the growth of HepG2 cells. Our analysis provides a comprehensive and unbiased resource of unmapped human transcripts and reveals their associations with specific cancers, providing potentially important new genes for therapeutic targeting.


Assuntos
Biomarcadores Tumorais/genética , MicroRNAs/genética , Neoplasias/genética , RNA Longo não Codificante/genética , Animais , Sequência de Bases , Linhagem Celular Tumoral , Proliferação de Células/genética , Mapeamento Cromossômico , Perfilação da Expressão Gênica , Genoma/genética , Gorilla gorilla/genética , Células HEK293 , Células Hep G2 , Sequenciamento de Nucleotídeos em Larga Escala , Histonas/genética , Humanos , Anotação de Sequência Molecular , Pan troglodytes/genética , Análise de Sequência de RNA
13.
J Virol ; 89(17): 8967-73, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26085148

RESUMO

UNLABELLED: Viruses are causally associated with a number of human malignancies. In this study, we sought to identify new virus-cancer associations by searching RNA sequencing data sets from >2,000 patients, encompassing 21 cancers from The Cancer Genome Atlas (TCGA), for the presence of viral sequences. In agreement with previous studies, we found human papillomavirus 16 (HPV16) and HPV18 in oropharyngeal cancer and hepatitis B and C viruses in liver cancer. Unexpectedly, however, we found HPV38, a cutaneous form of HPV associated with skin cancer, in 32 of 168 samples from endometrial cancer. In 12 of the HPV38-positive (HPV38(+)) samples, we observed at least one paired read that mapped to both human and HPV38 genomes, indicative of viral integration into the host DNA, something not previously demonstrated for HPV38. The expression levels of HPV38 transcripts were relatively low, and all 32 HPV38(+) samples belonged to the same experimental batch of 40 samples, whereas none of the other 128 endometrial carcinoma samples were HPV38(+), raising doubts about the significance of the HPV38 association. Moreover, the HPV38(+) samples contained the same 10 novel single nucleotide variations (SNVs), leading us to hypothesize that one patient was infected with this new isolate of HPV38, which was integrated into his/her genome and may have cross-contaminated other TCGA samples within batch 228. Based on our analysis, we propose guidelines to examine the batch effect, virus expression level, and SNVs as part of next-generation sequencing (NGS) data analysis for evaluating the significance of viral/pathogen sequences in clinical samples. IMPORTANCE: High-throughput RNA sequencing (RNA-Seq), followed by computational analysis, has vastly accelerated the identification of viral and other pathogenic sequences in clinical samples, but cross-contamination during the processing of the samples remain a major problem that can lead to erroneous conclusions. We found HPV38 sequences specifically present in RNA-Seq samples from endometrial cancer patients from TCGA, a virus not previously associated with this type of cancer. However, multiple lines of evidence suggest possible cross-contamination in these samples, which were processed together in the same batch. Despite this potential cross-contamination, our data indicate that we have detected a new isolate of HPV38 that appears to be integrated into the human genome. We also provide general guidelines for computational detection and interpretation of pathogen-disease associations.


Assuntos
Alphapapillomavirus/genética , Neoplasias do Endométrio/genética , Infecções por Papillomavirus/virologia , Neoplasias Cutâneas/genética , Integração Viral/genética , Sequência de Bases , Neoplasias do Endométrio/virologia , Feminino , Perfilação da Expressão Gênica , Biblioteca Gênica , Genoma Humano/genética , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Polimorfismo de Nucleotídeo Único/genética , RNA Viral/genética , Análise de Sequência de RNA , Neoplasias Cutâneas/virologia
14.
Ann N Y Acad Sci ; 1362: 68-76, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25988856

RESUMO

Peritoneal B-1a cells are characterized by their expression of CD5 and enrichment for germline-encoded IgM B cell receptors. Early studies showing expression of a diverse array of VDJ sequences among purified B-1a cells provided a molecular basis for understanding the heterogeneity of the B-1a cell repertoire. Antigen-driven positive selection and the identification of B-1a specific progenitors suggest multiple origins of B-1a cells. The introduction of new markers such as PD-L2, CD25, CD73, and PC1 (plasma cell alloantigen 1, also known as ectonucleotide phosphodiesterase/pyrophosphatase 1) further helped to identify phenotypically and functionally distinct B-1a subsets. Among many B-1a subsets defined by these new markers, PC1 is unique in that it subdivides B-1a cells into PC1(hi) and PC1(lo) subpopulations with distinct functions, such as production of natural IgM and gut IgA, response to the pneumococcal antigen PPS-3, secretion of interleukin-10, and support for T helper 1 (TH 1) cell differentiation. RNA sequencing of these subsets revealed differential expression of genes involved in cellular movement and immune cell trafficking. We will discuss these new insights underlying the heterogeneous nature of the B-1a cell repertoire.


Assuntos
Líquido Ascítico/citologia , Líquido Ascítico/fisiologia , Subpopulações de Linfócitos B/fisiologia , Heterogeneidade Genética , Animais , Diferenciação Celular/fisiologia , Humanos
15.
Immunity ; 38(1): 13-25, 2013 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-23352221

RESUMO

Interleukin-2 (IL-2) is a pleiotropic cytokine produced after antigen activation that plays pivotal roles in the immune response. Discovered as a T cell growth factor, IL-2 additionally promotes CD8(+) T cell and natural killer cell cytolytic activity and modulates T cell differentiation programs in response to antigen, promoting naïve CD4(+) T cell differentiation into T helper 1 (Th1) and T helper 2 (Th2) cells while inhibiting T helper 17 (Th17) and T follicular helper (Tfh) cell differentiation. Moreover, IL-2 is essential for the development and maintenance of T regulatory cells and for activation-induced cell death, thereby mediating tolerance and limiting inappropriate immune reactions. In this review, we focus on the molecular mechanisms and complex cellular actions of IL-2, its cooperative and opposing effects with other cytokines, and how both promoting and blocking the actions of IL-2 are being utilized in clinical medicine.


Assuntos
Tolerância Imunológica , Imunoterapia , Interleucina-2/fisiologia , Subpopulações de Linfócitos T/imunologia , Animais , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Diferenciação Celular/imunologia , Humanos , Memória Imunológica , Subunidade gama Comum de Receptores de Interleucina/genética , Subunidade gama Comum de Receptores de Interleucina/imunologia , Subunidade gama Comum de Receptores de Interleucina/metabolismo , Interleucina-15/metabolismo , Interleucina-2/metabolismo , Leucemia-Linfoma de Células T do Adulto/genética , Leucemia-Linfoma de Células T do Adulto/imunologia , Leucemia-Linfoma de Células T do Adulto/terapia , Receptores de Interleucina-2/genética , Receptores de Interleucina-2/metabolismo , Subpopulações de Linfócitos T/metabolismo , Linfócitos T Auxiliares-Indutores/citologia , Linfócitos T Auxiliares-Indutores/imunologia , Linfócitos T Reguladores/imunologia , Doenças por Imunodeficiência Combinada Ligada ao Cromossomo X/genética , Doenças por Imunodeficiência Combinada Ligada ao Cromossomo X/imunologia , Doenças por Imunodeficiência Combinada Ligada ao Cromossomo X/terapia
16.
Nat Immunol ; 13(12): 1187-95, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23104097

RESUMO

Interleukin 15 (IL-15) and IL-2 have distinct immunological functions even though both signal through the receptor subunit IL-2Rß and the common γ-chain (γ(c)). Here we found that in the structure of the IL-15-IL-15Rα-IL-2Rß-γ(c) quaternary complex, IL-15 binds to IL-2Rß and γ(c) in a heterodimer nearly indistinguishable from that of the IL-2-IL-2Rα-IL-2Rß-γ(c) complex, despite their different receptor-binding chemistries. IL-15Rα substantially increased the affinity of IL-15 for IL-2Rß, and this allostery was required for IL-15 trans signaling. Consistent with their identical IL-2Rß-γ(c) dimer geometries, IL-2 and IL-15 showed similar signaling properties in lymphocytes, with any differences resulting from disparate receptor affinities. Thus, IL-15 and IL-2 induced similar signals, and the cytokine specificity of IL-2Rα versus IL-15Rα determined cellular responsiveness. Our results provide new insights for the development of specific immunotherapeutics based on IL-15 or IL-2.


Assuntos
Interleucina-15/imunologia , Interleucina-2/imunologia , Animais , Sítios de Ligação , Linhagem Celular Tumoral , Cristalografia por Raios X , Humanos , Interleucina-15/química , Interleucina-15/metabolismo , Interleucina-2/química , Interleucina-2/metabolismo , Subunidade alfa de Receptor de Interleucina-2/metabolismo , Subunidade beta de Receptor de Interleucina-2/metabolismo , Ligantes , Linfócitos/imunologia , Linfócitos/metabolismo , Camundongos , Modelos Moleculares , Simulação de Dinâmica Molecular , Ligação Proteica , Multimerização Proteica , Estrutura Quaternária de Proteína , Transdução de Sinais
17.
Immunity ; 36(4): 586-99, 2012 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-22520852

RESUMO

Cytokine-activated STAT proteins dimerize and bind to high-affinity motifs, and N-terminal domain-mediated oligomerization of dimers allows tetramer formation and binding to low-affinity tandem motifs, but the functions of dimers versus tetramers are unknown. We generated Stat5a-Stat5b double knockin (DKI) N-domain mutant mice in which STAT5 proteins form dimers but not tetramers, identified cytokine-regulated genes whose expression required STAT5 tetramers, and defined dimer versus tetramer consensus motifs. Whereas Stat5-deficient mice exhibited perinatal lethality, DKI mice were viable; thus, STAT5 dimers were sufficient for survival. Nevertheless, STAT5 DKI mice had fewer CD4(+)CD25(+) T cells, NK cells, and CD8(+) T cells, with impaired cytokine-induced and homeostatic proliferation of CD8(+) T cells. Moreover, DKI CD8(+) T cell proliferation after viral infection was diminished and DKI Treg cells did not efficiently control colitis. Thus, tetramerization of STAT5 is critical for cytokine responses and normal immune function, establishing a critical role for STAT5 tetramerization in vivo.


Assuntos
Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Citocinas/biossíntese , Fator de Transcrição STAT5/química , Fator de Transcrição STAT5/metabolismo , Animais , Sítios de Ligação , Proliferação de Células , Sobrevivência Celular/imunologia , Colite/imunologia , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Técnicas de Introdução de Genes , Subunidade alfa de Receptor de Interleucina-2/biossíntese , Células Matadoras Naturais/metabolismo , Ativação Linfocitária , Vírus da Coriomeningite Linfocítica/imunologia , Vírus da Coriomeningite Linfocítica/patogenicidade , Camundongos , Camundongos Transgênicos , Multimerização Proteica , Fator de Transcrição STAT5/genética , Transdução de Sinais
18.
Curr Opin Immunol ; 23(5): 598-604, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21889323

RESUMO

Interleukin-2 (IL-2) is a pleiotropic cytokine that drives T-cell growth, augments NK cytolytic activity, induces the differentiation of regulatory T cells, and mediates activation-induced cell death. Along with IL-4, IL-7, IL-9, IL-15, and IL-21, IL-2 shares the common cytokine receptor γ chain, γ(c), which is mutated in humans with X-linked severe combined immunodeficiency. Herein, we primarily focus on the recently discovered complex roles of IL-2 in broadly modulating T cells for T helper cell differentiation. IL-2 does not specify the type of Th differentiation that occurs; instead, IL-2 modulates expression of receptors for other cytokines and transcription factors, thereby either promoting or inhibiting cytokine cascades that correlate with each Th differentiation state. In this fashion, IL-2 can prime and potentially maintain Th1 and Th2 differentiation as well as expand such populations of cells, whereas it inhibits Th17 differentiation but also can expand Th17 cells.


Assuntos
Diferenciação Celular/imunologia , Imunidade , Interleucina-2 , Transdução de Sinais/imunologia , Células Th1/imunologia , Células Th2/imunologia , Animais , Morte Celular/imunologia , Proliferação de Células , Regulação da Expressão Gênica/imunologia , Humanos , Fatores Imunológicos/imunologia , Fatores Imunológicos/metabolismo , Interleucina-2/imunologia , Interleucina-2/metabolismo , Células Matadoras Naturais/citologia , Células Matadoras Naturais/imunologia , Ativação Linfocitária/imunologia , Camundongos , Camundongos Transgênicos , Receptores de Citocinas/imunologia , Receptores de Citocinas/metabolismo , Transdução de Sinais/genética , Células Th1/citologia , Células Th2/citologia , Fatores de Transcrição/genética , Fatores de Transcrição/imunologia , Doenças por Imunodeficiência Combinada Ligada ao Cromossomo X/genética , Doenças por Imunodeficiência Combinada Ligada ao Cromossomo X/imunologia
19.
Blood ; 117(25): 6885-94, 2011 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-21527514

RESUMO

p90 ribosomal S6 kinase 2 (p90RSK2) is important in diverse cellular processes including gene expression, cell proliferation, and survival. We found that p90RSK2 is commonly activated in diverse leukemia cell lines expressing different leukemogenic tyrosine kinases, including BCR-ABL and FMS-like tyrosine kinase 3-internal tandem duplication (FLT3-ITD). Interestingly, in a murine BM transplantation (BMT) model, genetic deficiency of RSK2 did not affect the pathogenesis or disease progression of BCR-ABL-induced myeloproliferative neoplasm (PN). In contrast, FLT3-ITD induced a T-cell acute lymphoblastic leukemia in BMT mice receiving RSK2 knockout (KO) BM cells, phenotypically distinct from the myeloproliferative neoplasm induced by FLT3-ITD using wild-type BM cells. In consonance with these results, inhibition of RSK2 by an RSK inhibitor, fmk, did not effectively induce apoptosis in BCR-ABL-expressing murine Ba/F3 cells, human K562 cells or primary tissue samples from CML patients, whereas fmk treatment induced significant apoptotic cell death not only in FLT3-ITD-positive Ba/F3 cells, human Molm14 and Mv(4;11) leukemia cells, but also in primary tissue samples from AML patients. These results suggest that RSK2 is dispensable for BCR-ABL-induced myeloid leukemia, but may be required for pathogenesis and lineage determination in FLT3-ITD-induced hematopoietic transformation. RSK2 may thus represent an alternative therapeutic target in the treatment of FLT3-ITD-positive leukemia.


Assuntos
Proteínas de Fusão bcr-abl/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/enzimologia , Leucemia Mieloide/enzimologia , Proteínas Quinases S6 Ribossômicas 90-kDa/metabolismo , Tirosina Quinase 3 Semelhante a fms/genética , Animais , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Ativação Enzimática , Inibidores Enzimáticos/farmacologia , Proteínas de Fusão bcr-abl/metabolismo , Técnicas de Inativação de Genes , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Leucemia Mieloide/genética , Leucemia Mieloide/patologia , Camundongos , Camundongos Endogâmicos BALB C , Proteínas Quinases S6 Ribossômicas 90-kDa/antagonistas & inibidores , Proteínas Quinases S6 Ribossômicas 90-kDa/genética , Tirosina Quinase 3 Semelhante a fms/metabolismo
20.
Nat Immunol ; 12(6): 551-9, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21516110

RESUMO

Helper T cells control host defense against pathogens. The receptors for interleukin 12 (IL-12), IL-4 and IL-6 are required for differentiation into the T(H)1, T(H)2 and T(H)17 subsets of helper T cells, respectively. IL-2 signaling via the transcription factor STAT5 controls T(H)2 differentiation by regulating both the T(H)2 cytokine gene cluster and expression of Il4ra, the gene encoding the IL-4 receptor α-chain. Here we show that IL-2 regulated T(H)1 differentiation, inducing STAT5-dependent expression of the IL-12 receptor ß2-chain (IL-12Rß2) and the transcription factor T-bet, with impaired human T(H)1 differentiation when IL-2 was blocked. T(H)1 differentiation was also impaired in mouse Il2(-/-) T cells but was restored by IL-12Rß2 expression. Consistent with the inhibition of T(H)17 differentiation by IL-2, treatment with IL-2 resulted in lower expression of the genes encoding the IL-6 receptor α-chain (Il6ra) and the IL-6 signal transducer gp130 (encoded by Il6st), and retroviral transduction of Il6st augmented T(H)17 differentiation even when IL-2 was present. Thus, IL-2 influences helper T cell differentiation by modulating the expression of cytokine receptors to help specify and maintain differentiated states.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Interleucina-2/farmacologia , Receptores de Citocinas/genética , Linfócitos T Auxiliares-Indutores/efeitos dos fármacos , Animais , Diferenciação Celular/genética , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Citometria de Fluxo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica/efeitos dos fármacos , Células HEK293 , Humanos , Interleucina-2/genética , Interleucina-2/metabolismo , Camundongos , Camundongos da Linhagem 129 , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Análise de Sequência com Séries de Oligonucleotídeos , Receptores de Citocinas/metabolismo , Receptores de Interleucina-12/genética , Receptores de Interleucina-12/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fator de Transcrição STAT5/genética , Fator de Transcrição STAT5/metabolismo , Proteínas com Domínio T/genética , Proteínas com Domínio T/metabolismo , Linfócitos T Auxiliares-Indutores/metabolismo , Células Th1/efeitos dos fármacos , Células Th1/metabolismo
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