RESUMO
Cell identity and function largely rely on the programming of transcriptomes during development and differentiation. Signature gene expression programs are orchestrated by regulatory circuits consisting of cis-acting promoters and enhancers, which respond to a plethora of cues via the action of transcription factors. In turn, transcription factors direct epigenetic modifications to revise chromatin landscapes, and drive contacts between distal promoter-enhancer combinations. In immune cells, regulatory circuits for effector genes are especially complex and flexible, utilizing distinct sets of transcription factors and enhancers, depending on the cues each cell type receives during an infection, after sensing cellular damage, or upon encountering a tumor. Here, we review major players in the coordination of gene regulatory programs within innate and adaptive immune cells, as well as integrative omics approaches that can be leveraged to decipher their underlying circuitry.
Assuntos
Cromatina , Redes Reguladoras de Genes , Animais , Regulação da Expressão Gênica , Humanos , Regiões Promotoras Genéticas , Fatores de Transcrição/genéticaRESUMO
Evolution of SARS-CoV-2 requires the reassessment of current vaccine measures. Here, we characterized BA.2.86 and XBB-derived variant FLip by investigating their neutralization alongside D614G, BA.1, BA.2, BA.4/5, XBB.1.5, and EG.5.1 by sera from 3-dose-vaccinated and bivalent-vaccinated healthcare workers, XBB.1.5-wave-infected first responders, and monoclonal antibody (mAb) S309. We assessed the biology of the variant spikes by measuring viral infectivity and membrane fusogenicity. BA.2.86 is less immune evasive compared to FLip and other XBB variants, consistent with antigenic distances. Importantly, distinct from XBB variants, mAb S309 was unable to neutralize BA.2.86, likely due to a D339H mutation based on modeling. BA.2.86 had relatively high fusogenicity and infectivity in CaLu-3 cells but low fusion and infectivity in 293T-ACE2 cells compared to some XBB variants, suggesting a potentially different conformational stability of BA.2.86 spike. Overall, our study underscores the importance of SARS-CoV-2 variant surveillance and the need for updated COVID-19 vaccines.
Assuntos
Vacinas contra COVID-19 , COVID-19 , Evasão da Resposta Imune , SARS-CoV-2 , Humanos , Anticorpos Monoclonais , Anticorpos Neutralizantes , Anticorpos Antivirais , COVID-19/imunologia , SARS-CoV-2/classificação , SARS-CoV-2/fisiologiaRESUMO
Intestinal intraepithelial lymphocytes (IELs) exhibit prompt innate-like responses to microenvironmental cues and require strict control of effector functions. Here we showed that Aiolos, an Ikaros zinc-finger family member encoded by Ikzf3, acted as a regulator of IEL activation. Ikzf3-/- CD8αα+ IELs had elevated expression of NK receptors, cytotoxic enzymes, cytokines and chemokines. Single-cell RNA sequencing of Ikzf3-/- and Ikzf3+/+ IELs showed an amplified effector machinery in Ikzf3-/- CD8αα+ IELs compared to Ikzf3+/+ counterparts. Ikzf3-/- CD8αα+ IELs had increased responsiveness to interleukin-15, which explained a substantial part, but not all, of the observed phenotypes. Aiolos binding sites were close to those for the transcription factors STAT5 and RUNX, which promote interleukin-15 signaling and cytolytic programs, and Ikzf3 deficiency partially increased chromatin accessibility and histone acetylation in these regions. Ikzf3 deficiency in mice enhanced susceptibility to colitis, underscoring the relevance of Aiolos in regulating the effector function in IELs.
Assuntos
Linfócitos Intraepiteliais , Fatores de Transcrição , Animais , Camundongos , Antígenos CD8/metabolismo , Interleucina-15/metabolismo , Mucosa Intestinal/metabolismo , Linfócitos Intraepiteliais/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
Innate lymphocytes encompass a diverse array of phenotypic identities with specialized functions. DNA methylation and hydroxymethylation are essential for epigenetic fidelity and fate commitment. The landscapes of these modifications are unknown in innate lymphocytes. Here, we characterized the whole-genome distribution of methyl-CpG and 5-hydroxymethylcytosine (5hmC) in mouse innate lymphoid cell 3 (ILC3), ILC2 and natural killer (NK) cells. We identified differentially methylated regions (DMRs) and differentially hydroxymethylated regions (DHMRs) between ILC and NK cell subsets and correlated them with transcriptional signatures. We associated lineage-determining transcription factors (LDTFs) with demethylation and demonstrated unique patterns of DNA methylation/hydroxymethylation in relationship to open chromatin regions (OCRs), histone modifications and TF-binding sites. We further identified an association between hydroxymethylation and NK cell superenhancers (SEs). Using mice lacking the DNA hydroxymethylase TET2, we showed the requirement for TET2 in optimal production of hallmark cytokines by ILC3s and interleukin-17A (IL-17A) by inflammatory ILC2s. These findings provide a powerful resource for studying innate lymphocyte epigenetic regulation and decode the regulatory logic governing their identity.
Assuntos
Metilação de DNA , Imunidade Inata , Animais , Cromatina/genética , Epigênese Genética , Imunidade Inata/genética , Células Matadoras Naturais , Linfócitos , CamundongosRESUMO
Natural killer (NK) cells develop from common progenitors but diverge into distinct subsets, which differ in cytokine production, cytotoxicity, homing, and memory traits. Given their promise in adoptive cell therapies for cancer, a deeper understanding of regulatory modules controlling clinically beneficial NK phenotypes is of high priority. We report integrated "-omics" analysis of human NK subsets, which revealed super-enhancers associated with gene cohorts that may coordinate NK functions and localization. A transcription factor-based regulatory scheme also emerged, which is evolutionarily conserved and shared by innate and adaptive lymphocytes. For both NK and T lineages, a TCF1-LEF1-MYC axis dominated the regulatory landscape of long-lived, proliferative subsets that traffic to lymph nodes. In contrast, effector populations circulating between blood and peripheral tissues shared a PRDM1-dominant landscape. This resource defines transcriptional modules, regulated by feedback loops, which may be leveraged to enhance phenotypes for NK cell-based therapies.
Assuntos
Células Matadoras Naturais/classificação , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/fisiologia , Citocinas/imunologia , Citocinas/metabolismo , Regulação da Expressão Gênica/genética , Regulação da Expressão Gênica/imunologia , Humanos , FenótipoRESUMO
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
RESUMO
Innate lymphoid cells (ILCs) are tissue-resident lymphocytes categorized on the basis of their core regulatory programs and the expression of signature cytokines. Human ILC3s that produce the cytokine interleukin-22 convert into ILC1-like cells that produce interferon-γ in vitro, but whether this conversion occurs in vivo remains unclear. In the present study we found that ILC3s and ILC1s in human tonsils represented the ends of a spectrum that included additional discrete subsets. RNA velocity analysis identified an intermediate ILC3-ILC1 cluster, which had strong directionality toward ILC1s. In humanized mice, the acquisition of ILC1 features by ILC3s showed tissue dependency. Chromatin studies indicated that the transcription factors Aiolos and T-bet cooperated to repress regulatory elements active in ILC3s. A transitional ILC3-ILC1 population was also detected in the human intestine. We conclude that ILC3s undergo conversion into ILC1-like cells in human tissues in vivo, and that tissue factors and Aiolos were required for this process.
Assuntos
Imunidade Inata/imunologia , Interferon gama/metabolismo , Interleucinas/metabolismo , Mucosa Intestinal/imunologia , Linfócitos/imunologia , Tonsila Palatina/imunologia , Animais , Diferenciação Celular/imunologia , Células Cultivadas , Criança , Pré-Escolar , Humanos , Fator de Transcrição Ikaros/metabolismo , Mucosa Intestinal/citologia , Linfócitos/classificação , Linfócitos/citologia , Camundongos , Proteínas com Domínio T/metabolismo , Interleucina 22RESUMO
Innate lymphoid cells (ILCs) serve as sentinels in mucosal tissues, sensing release of soluble inflammatory mediators, rapidly communicating danger via cytokine secretion, and functioning as guardians of tissue homeostasis. Although ILCs have been extensively studied in model organisms, little is known about these "first responders" in humans, especially their lineage and functional kinships to cytokine-secreting T helper (Th) cell counterparts. Here, we report gene regulatory circuitries for four human ILC-Th counterparts derived from mucosal environments, revealing that each ILC subset diverges as a distinct lineage from Th and circulating natural killer cells but shares circuitry devoted to functional polarization with their Th counterparts. Super-enhancers demarcate cohorts of cell-identity genes in each lineage, uncovering new modes of regulation for signature cytokines, new molecules that likely impart important functions to ILCs, and potential mechanisms for autoimmune disease SNP associations within ILC-Th subsets.
Assuntos
Linfócitos/citologia , Linfócitos/imunologia , Imunidade Adaptativa , Animais , Citocinas/imunologia , Citocinas/metabolismo , Elementos Facilitadores Genéticos , Humanos , Imunidade Inata , Imunidade nas Mucosas , Células Matadoras Naturais , Linfócitos/metabolismo , Camundongos , Tonsila Palatina/citologia , Linfócitos T Auxiliares-Indutores/citologia , Linfócitos T Auxiliares-Indutores/imunologia , Linfócitos T Auxiliares-Indutores/metabolismo , Fatores de Transcrição/metabolismo , TranscriptomaRESUMO
In the mammalian intestine, crypts of Leiberkühn house intestinal epithelial stem/progenitor cells at their base. The mammalian intestine also harbors a diverse array of microbial metabolite compounds that potentially modulate stem/progenitor cell activity. Unbiased screening identified butyrate, a prominent bacterial metabolite, as a potent inhibitor of intestinal stem/progenitor proliferation at physiologic concentrations. During homeostasis, differentiated colonocytes metabolized butyrate likely preventing it from reaching proliferating epithelial stem/progenitor cells within the crypt. Exposure of stem/progenitor cells in vivo to butyrate through either mucosal injury or application to a naturally crypt-less host organism led to inhibition of proliferation and delayed wound repair. The mechanism of butyrate action depended on the transcription factor Foxo3. Our findings indicate that mammalian crypt architecture protects stem/progenitor cell proliferation in part through a metabolic barrier formed by differentiated colonocytes that consume butyrate and stimulate future studies on the interplay of host anatomy and microbiome metabolism.
Assuntos
Bactérias/metabolismo , Butiratos/metabolismo , Colo/citologia , Colo/microbiologia , Microbioma Gastrointestinal , Células-Tronco/metabolismo , Acil-CoA Desidrogenase/deficiência , Acil-CoA Desidrogenase/genética , Animais , Proliferação de Células , Intestino Delgado/citologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Oxirredução , Moléculas com Motivos Associados a Patógenos/metabolismo , Células-Tronco/citologia , Peixe-ZebraRESUMO
The genome is organized into topologically associated domains (TADs) that enclose smaller subTADs. Here, we identify and characterize an enhancer that is located in the middle of the V gene region of the immunoglobulin kappa light chain (Igκ) locus that becomes active preceding the stage at which this locus undergoes V(D)J recombination. This enhancer is a hub of long-range chromatin interactions connecting subTADs in the V gene region with the recombination center at the J genes. Deletion of this element results in a highly altered long-range chromatin interaction pattern across the locus and, importantly, affects individual V gene utilization locus-wide. These results indicate the existence of an enhancer-dependent framework in the Igκ locus and further suggest that the composition of the diverse antibody repertoire is regulated in a subTAD-specific manner. This enhancer thus plays a structural role in orchestrating the proper folding of the Igκ locus in preparation for V(D)J recombination.
Assuntos
Diversidade de Anticorpos , Núcleo Celular/imunologia , Elementos Facilitadores Genéticos , Rearranjo Gênico do Linfócito B , Cadeias kappa de Imunoglobulina/imunologia , Células Precursoras de Linfócitos B/imunologia , Receptores de Antígenos de Linfócitos B/imunologia , Animais , Linhagem Celular Tumoral , Núcleo Celular/genética , Núcleo Celular/metabolismo , Forma do Núcleo Celular , Montagem e Desmontagem da Cromatina , Genótipo , Células HEK293 , Humanos , Cadeias kappa de Imunoglobulina/química , Cadeias kappa de Imunoglobulina/genética , Cadeias kappa de Imunoglobulina/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Fenótipo , Células Precursoras de Linfócitos B/metabolismo , Conformação Proteica , Receptores de Antígenos de Linfócitos B/química , Receptores de Antígenos de Linfócitos B/genética , Receptores de Antígenos de Linfócitos B/metabolismo , Relação Estrutura-AtividadeRESUMO
The immunoglobulin heavy-chain (IgH) gene locus undergoes radial repositioning within the nucleus and locus contraction in preparation for gene recombination. We demonstrate that IgH locus conformation involves two levels of chromosomal compaction. At the first level, the locus folds into several multilooped domains. One such domain at the 3' end of the locus requires an enhancer, Eµ; two other domains at the 5' end are Eµ independent. At the second level, these domains are brought into spatial proximity by Eµ-dependent interactions with specific sites within the V(H) region. Eµ is also required for radial repositioning of IgH alleles, indicating its essential role in large-scale chromosomal movements in developing lymphocytes. Our observations provide a comprehensive view of the conformation of IgH alleles in pro-B cells and the mechanisms by which it is established.
Assuntos
Linfócitos B/metabolismo , Núcleo Celular/genética , Cromatina/química , Genes de Cadeia Pesada de Imunoglobulina , Cadeias Pesadas de Imunoglobulinas/genética , Animais , Fator de Ligação a CCCTC , Elementos Facilitadores Genéticos , Região Variável de Imunoglobulina , Camundongos , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Proteínas Repressoras/metabolismo , Recombinação V(D)J , Fator de Transcrição YY1/metabolismoRESUMO
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a highly transmissible coronavirus responsible for the global COVID-19 pandemic. Herein, we provide evidence that SARS-CoV-2 spreads through cell-cell contact in cultures, mediated by the spike glycoprotein. SARS-CoV-2 spike is more efficient in facilitating cell-to-cell transmission than is SARS-CoV spike, which reflects, in part, their differential cell-cell fusion activity. Interestingly, treatment of cocultured cells with endosomal entry inhibitors impairs cell-to-cell transmission, implicating endosomal membrane fusion as an underlying mechanism. Compared with cell-free infection, cell-to-cell transmission of SARS-CoV-2 is refractory to inhibition by neutralizing antibody or convalescent sera of COVID-19 patients. While angiotensin-converting enzyme 2 enhances cell-to-cell transmission, we find that it is not absolutely required. Notably, despite differences in cell-free infectivity, the authentic variants of concern (VOCs) B.1.1.7 (alpha) and B.1.351 (beta) have similar cell-to-cell transmission capability. Moreover, B.1.351 is more resistant to neutralization by vaccinee sera in cell-free infection, whereas B.1.1.7 is more resistant to inhibition by vaccinee sera in cell-to-cell transmission. Overall, our study reveals critical features of SARS-CoV-2 spike-mediated cell-to-cell transmission, with important implications for a better understanding of SARS-CoV-2 spread and pathogenesis.
Assuntos
COVID-19/imunologia , COVID-19/transmissão , SARS-CoV-2/imunologia , Internalização do Vírus , Enzima de Conversão de Angiotensina 2 , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais , COVID-19/terapia , Fusão Celular , Chlorocebus aethiops , Células HEK293 , Humanos , Imunização Passiva , Glicoproteína da Espícula de Coronavírus/imunologia , Células Vero , Soroterapia para COVID-19RESUMO
Most B-cell lymphomas arise in the germinal center (GC), where humoral immune responses evolve from potentially oncogenic cycles of mutation, proliferation, and clonal selection. Although lymphoma gene expression diverges significantly from GC B cells, underlying mechanisms that alter the activities of corresponding regulatory elements (REs) remain elusive. Here we define the complete pathogenic circuitry of human follicular lymphoma (FL), which activates or decommissions REs from normal GC B cells and commandeers enhancers from other lineages. Moreover, independent sets of transcription factors, whose expression was deregulated in FL, targeted commandeered versus decommissioned REs. Our approach revealed two distinct subtypes of low-grade FL, whose pathogenic circuitries resembled GC B or activated B cells. FL-altered enhancers also were enriched for sequence variants, including somatic mutations, which disrupt transcription-factor binding and expression of circuit-linked genes. Thus, the pathogenic regulatory circuitry of FL reveals distinct genetic and epigenetic etiologies for GC B-cell transformation.
Assuntos
Linfócitos B/fisiologia , Redes Reguladoras de Genes , Centro Germinativo/patologia , Linfoma de Células B/genética , Elementos Reguladores de Transcrição/imunologia , Adulto , Idoso , Transformação Celular Neoplásica , Epigênese Genética , Feminino , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Ativação Linfocitária/genética , Masculino , Pessoa de Meia-Idade , Mutação/genética , Elementos Reguladores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
The transcription factor BATF controls the differentiation of interleukin 17 (IL-17)-producing helper T cells (T(H)17 cells) by regulating expression of the transcription factor RORγt itself and RORγt target genes such as Il17. Here we report the mechanism by which BATF controls in vivo class-switch recombination (CSR). In T cells, BATF directly controlled expression of the transcription factors Bcl-6 and c-Maf, both of which are needed for development of follicular helper T cells (T(FH) cells). Restoring T(FH) cell activity to Batf(-/-) T cells in vivo required coexpression of Bcl-6 and c-Maf. In B cells, BATF directly controlled the expression of both activation-induced cytidine deaminase (AID) and of germline transcripts of the intervening heavy-chain region and constant heavy-chain region (I(H)-C(H)). Thus, BATF functions at multiple hierarchical levels in two cell types to globally regulate switched antibody responses in vivo.
Assuntos
Linfócitos B/imunologia , Fatores de Transcrição de Zíper de Leucina Básica/imunologia , Switching de Imunoglobulina/imunologia , Linfócitos T/imunologia , Proteínas Adaptadoras de Transdução de Sinal , Animais , Linfócitos B/metabolismo , Fatores de Transcrição de Zíper de Leucina Básica/genética , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Ligante de CD40/genética , Ligante de CD40/imunologia , Ligante de CD40/metabolismo , Proteínas de Transporte/genética , Proteínas de Transporte/imunologia , Proteínas de Transporte/metabolismo , Células Cultivadas , Citidina Desaminase/genética , Citidina Desaminase/metabolismo , Feminino , Citometria de Fluxo , Perfilação da Expressão Gênica , Centro Germinativo/imunologia , Centro Germinativo/metabolismo , Switching de Imunoglobulina/genética , Ativação Linfocitária/imunologia , Masculino , Camundongos , Camundongos da Linhagem 129 , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos , Camundongos Knockout , Análise de Sequência com Séries de Oligonucleotídeos , Proteínas Proto-Oncogênicas c-bcl-6/genética , Proteínas Proto-Oncogênicas c-bcl-6/imunologia , Proteínas Proto-Oncogênicas c-bcl-6/metabolismo , Recombinação Genética , Linfócitos T/metabolismoRESUMO
The structure of broken DNA ends is a critical determinant of the pathway used for DNA double-strand break (DSB) repair. Here, we develop an approach involving the hairpin capture of DNA end structures (HCoDES), which elucidates chromosomal DNA end structures at single-nucleotide resolution. HCoDES defines structures of physiologic DSBs generated by the RAG endonuclease, as well as those generated by nucleases widely used for genome editing. Analysis of G1 phase cells deficient in H2AX or 53BP1 reveals DNA ends that are frequently resected to form long single-stranded overhangs that can be repaired by mutagenic pathways. In addition to 3' overhangs, many of these DNA ends unexpectedly form long 5' single-stranded overhangs. The divergence in DNA end structures resolved by HCoDES suggests that H2AX and 53BP1 may have distinct activities in end protection. Thus, the high-resolution end structures obtained by HCoDES identify features of DNA end processing during DSB repair.