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1.
Proc Natl Acad Sci U S A ; 117(52): 33446-33454, 2020 12 29.
Artigo em Inglês | MEDLINE | ID: mdl-33318189

RESUMO

Reduced nutrient intake is a widely conserved manifestation of sickness behavior with poorly characterized effects on adaptive immune responses. During infectious challenges, naive T cells encountering their cognate antigen become activated and differentiate into highly proliferative effector T cells. Despite their evident metabolic shift upon activation, it remains unclear how effector T cells respond to changes in nutrient availability in vivo. Here, we show that spontaneous or imposed feeding reduction during infection decreases the numbers of splenic lymphocytes. Effector T cells showed cell-intrinsic responses dependent on the nuclear receptor Farnesoid X Receptor (FXR). Deletion of FXR in T cells prevented starvation-induced loss of lymphocytes and increased effector T cell fitness in nutrient-limiting conditions, but imparted greater weight loss to the host. FXR deficiency increased the contribution of glutamine and fatty acids toward respiration and enhanced cell survival under low-glucose conditions. Provision of glucose during anorexia of infection rescued effector T cells, suggesting that this sugar is a limiting nutrient for activated lymphocytes and that alternative fuel usage may affect cell survival in starved animals. Altogether, we identified a mechanism by which the host scales immune responses according to food intake, featuring FXR as a T cell-intrinsic sensor.


Assuntos
Comportamento Alimentar , Coriomeningite Linfocítica/imunologia , Receptores Citoplasmáticos e Nucleares/metabolismo , Linfócitos T/imunologia , Animais , Anorexia/virologia , Jejum , Coriomeningite Linfocítica/patologia , Coriomeningite Linfocítica/virologia , Vírus da Coriomeningite Linfocítica/fisiologia , Camundongos Endogâmicos C57BL , Nutrientes/metabolismo , Baço/patologia , Transcrição Genética
2.
Int J Mol Sci ; 22(1)2020 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-33375121

RESUMO

Regulatory T cells (Tregs) prevent excessive immune responses and limit immune pathology upon infections. To fulfill this role in different immune environments elicited by different types of pathogens, Tregs undergo functional specialization into distinct subsets. During acute type 1 immune responses, type 1 Tregs are induced and recruited to the site of ongoing Th1 responses to efficiently control Th1 responses. However, whether a similar specialization process also takes place following chronic infections is still unknown. In this study, we investigated Treg specialization in persistent viral infections using lymphocytic choriomeningitis virus (LCMV) and murine cytomegalovirus (MCMV) infection as models for chronic and latent infections, respectively. We identify CD85k as a Th1-specific co-inhibitory receptor with sustained expression in persistent viral infections and show that recombinant CD85k inhibits LCMV-specific effector T cells. Furthermore, expression of the CD85k ligand ALCAM is induced on LCMV-specific and exhausted T cells during chronic LCMV infection. Finally, we demonstrate that type 1 Tregs arising during chronic LCMV infection suppress Th1 effector cells in an ALCAM-dependent manner. These results extend the current knowledge of Treg specialization from acute to persistent viral infections and reveal an important functional role of CD85k in Treg-mediated suppression of type 1 immunity.


Assuntos
Vírus da Coriomeningite Linfocítica/imunologia , Glicoproteínas de Membrana/imunologia , Muromegalovirus/imunologia , Receptores Imunológicos/imunologia , Linfócitos T Reguladores/imunologia , Animais , Antígenos CD/imunologia , Antígenos CD/metabolismo , Moléculas de Adesão Celular Neuronais/imunologia , Moléculas de Adesão Celular Neuronais/metabolismo , Linhagem Celular , Células Cultivadas , Infecções por Herpesviridae/imunologia , Infecções por Herpesviridae/metabolismo , Infecções por Herpesviridae/virologia , Coriomeningite Linfocítica/imunologia , Coriomeningite Linfocítica/metabolismo , Coriomeningite Linfocítica/virologia , Vírus da Coriomeningite Linfocítica/fisiologia , Glicoproteínas de Membrana/metabolismo , Camundongos Endogâmicos C57BL , Muromegalovirus/fisiologia , Receptores Imunológicos/metabolismo , Linfócitos T Reguladores/metabolismo , Linfócitos T Reguladores/virologia , Células Th1/imunologia , Células Th1/metabolismo
3.
Proc Natl Acad Sci U S A ; 117(40): 24998-25007, 2020 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-32958643

RESUMO

Infections elicit immune adaptations to enable pathogen resistance and/or tolerance and are associated with compositional shifts of the intestinal microbiome. However, a comprehensive understanding of how infections with pathogens that exhibit distinct capability to spread and/or persist differentially change the microbiome, the underlying mechanisms, and the relative contribution of individual commensal species to immune cell adaptations is still lacking. Here, we discovered that mouse infection with a fast-spreading and persistent (but not a slow-spreading acute) isolate of lymphocytic choriomeningitis virus induced large-scale microbiome shifts characterized by increased Verrucomicrobia and reduced Firmicute/Bacteroidetes ratio. Remarkably, the most profound microbiome changes occurred transiently after infection with the fast-spreading persistent isolate, were uncoupled from sustained viral loads, and were instead largely caused by CD8 T cell responses and/or CD8 T cell-induced anorexia. Among the taxa enriched by infection with the fast-spreading virus, Akkermansia muciniphila, broadly regarded as a beneficial commensal, bloomed upon starvation and in a CD8 T cell-dependent manner. Strikingly, oral administration of A. muciniphila suppressed selected effector features of CD8 T cells in the context of both infections. Our findings define unique microbiome differences after chronic versus acute viral infections and identify CD8 T cell responses and downstream anorexia as driver mechanisms of microbial dysbiosis after infection with a fast-spreading virus. Our data also highlight potential context-dependent effects of probiotics and suggest a model in which changes in host behavior and downstream microbiome dysbiosis may constitute a previously unrecognized negative feedback loop that contributes to CD8 T cell adaptations after infections with fast-spreading and/or persistent pathogens.


Assuntos
Anorexia/imunologia , Antígenos CD8/imunologia , Memória Imunológica/imunologia , Coriomeningite Linfocítica/imunologia , Viroses/imunologia , Animais , Anorexia/microbiologia , Anorexia/virologia , Antígenos CD8/metabolismo , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/microbiologia , Disbiose/imunologia , Disbiose/microbiologia , Disbiose/virologia , Firmicutes/imunologia , Firmicutes/metabolismo , Microbioma Gastrointestinal/imunologia , Humanos , Coriomeningite Linfocítica/microbiologia , Coriomeningite Linfocítica/patologia , Vírus da Coriomeningite Linfocítica/patogenicidade , Camundongos , Linfócitos T/imunologia , Linfócitos T/microbiologia , Verrucomicrobia/imunologia , Verrucomicrobia/patogenicidade , Viroses/microbiologia , Viroses/patologia
4.
Nat Commun ; 11(1): 4454, 2020 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-32901001

RESUMO

Chronic viral infections are often associated with impaired CD8+ T cell function, referred to as exhaustion. Although the molecular and cellular circuits involved in CD8+ T cell exhaustion are well defined, with sustained presence of antigen being one important parameter, how much T cell receptor (TCR) signaling is actually ongoing in vivo during established chronic infection is unclear. Here, we characterize the in vivo TCR signaling of virus-specific exhausted CD8+ T cells in a mouse model, leveraging TCR signaling reporter mice in combination with transcriptomics. In vivo signaling in exhausted cells is low, in contrast to their in vitro signaling potential, and despite antigen being abundantly present. Both checkpoint blockade and adoptive transfer of naïve target cells increase TCR signaling, demonstrating that engagement of co-inhibitory receptors curtails CD8+ T cell signaling and function in vivo.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Coriomeningite Linfocítica/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Transferência Adotiva , Animais , Antígeno B7-H1/antagonistas & inibidores , Antígeno B7-H1/imunologia , Linfócitos T CD8-Positivos/virologia , Doença Crônica , Citotoxicidade Imunológica , Modelos Animais de Doenças , Regulação para Baixo , Tolerância Imunológica , Imunidade Celular , Técnicas In Vitro , Ativação Linfocitária , Coriomeningite Linfocítica/genética , Vírus da Coriomeningite Linfocítica/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares/genética , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares/imunologia , Receptor de Morte Celular Programada 1/imunologia , RNA-Seq , Transdução de Sinais/imunologia
5.
J Vis Exp ; (160)2020 06 27.
Artigo em Inglês | MEDLINE | ID: mdl-32658202

RESUMO

Tissue-resident memory T cell (TRM) is a rapidly expanding field of immunology research. Isolating T cells from various non-lymphoid tissues is one of the key steps to investigate TRMs. There are slight variations in lymphocyte isolation protocols for different organs. Kidney is an essential non-lymphoid organ with numerous immune cell infiltration especially after pathogen exposure or autoimmune activation. In recent years, multiple labs including our own have started characterizing kidney resident CD8+ T cells in various physiological and pathological settings in both mouse and human. Due to the abundance of T lymphocytes, kidney represents an attractive model organ to study TRMs in non-mucosal or non-barrier tissues. Here, we will describe a protocol commonly used in TRM-focused labs to isolate CD8+ T cells from mouse kidneys following systemic viral infection. Briefly, using an acute lymphocytic choriomeningitis virus (LCMV) infection model in C57BL/6 mice, we demonstrate intravascular CD8+ T cell labeling, enzymatic digestion, and density gradient centrifugation to isolate and enrich lymphocytes from mouse kidneys to make samples ready for the subsequent flow cytometry analysis.


Assuntos
Linfócitos T CD8-Positivos/citologia , Citometria de Fluxo , Rim/citologia , Animais , Linfócitos T CD8-Positivos/imunologia , Modelos Animais de Doenças , Memória Imunológica/imunologia , Rim/imunologia , Coriomeningite Linfocítica/imunologia , Coriomeningite Linfocítica/patologia , Vírus da Coriomeningite Linfocítica/imunologia , Camundongos , Camundongos Endogâmicos C57BL
6.
J Virol ; 94(18)2020 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-32641478

RESUMO

Checkpoint inhibitors are effective in restoring exhausted CD8+ T cell responses in persistent viral infections or tumors. Several compounds are in clinical use for different malignancies, but trials in patients with chronic viral infections have also been conducted. In a mouse model of persistent lymphocytic choriomeningitis virus (LCMV) infection, it was shown that checkpoint inhibitor treatment increased T cell proliferation and functionality, but its influence on the antigen-specific T cell receptor (TCR) repertoire is unknown. NP396-specific CD8+ T cells dominate during acute LCMV infection and are predominantly exhausted during chronic infection. Next-generation sequencing of NP396-specific TCRs showed that exhaustion corresponds with a significantly reduced NP396-specific TCR repertoire diversity: Shannon indices of 4 in immunized mice to 2.6 in persistently infected mice. Anti-PD-L1 treatment during persistent LCMV infection restored NP396-specific T cell responses and reduced viral titers. Nevertheless, anti-PD-L1-treated mice showed an even more narrowed TCR repertoire, with reduced TCR diversity compared to that of persistently infected control mice (Shannon indices of 2.1 and 2.6, respectively). Interestingly, anti-PD-L1 treatment-induced narrowing of the TCR repertoire negatively correlates with functional and physical restoration of the antigen-specific T cell response. Further, we found that private, hyperexpanded TCR clonotypes dominated the T cell response after anti-PD-L1 treatment. Although being private, these top clonotypes from anti-PD-L1-treated mice revealed a more closely related CDR3 motif than those of top clonotypes from persistently infected control mice. In conclusion, although targeting the PD-1/PD-L1 pathway reinvigorates exhausted CD8+ T cells, it fails to restore T cell repertoire diversity.IMPORTANCE Checkpoint inhibitors are effective immunotherapeutics to restore cancer- and virus-induced exhausted CD8+ T cells, by enhancing the quality and survival of immune responses. Although checkpoint inhibitors are already used as therapy against various cancers, not much is known about their multifaceted impact on the exhausted CD8+ T cell receptor (TCR) repertoire. This report describes for the first time the evolvement of an exhausted antigen-specific CD8+ TCR repertoire under checkpoint inhibitor treatment. By using a well-established virus model, we were able to show major shifts toward oligoclonality of the CD8+ TCR repertoire response against a massively exhausted lymphocytic choriomeningitis virus (LCMV) epitope. While supporting viral control in the LCMV model, oligoclonality and more private of TCR repertoires may impact future pathogenic challenges and may promote viral escape. Our results may explain the ongoing problems of viral escapes, unpredictable autoimmunity, and heterogeneous responses appearing as adverse effects of checkpoint inhibitor treatments.


Assuntos
Antígeno B7-H1/imunologia , Coriomeningite Linfocítica/imunologia , Vírus da Coriomeningite Linfocítica/imunologia , Nucleoproteínas/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Animais , Anticorpos Neutralizantes/farmacologia , Antígeno B7-H1/antagonistas & inibidores , Antígeno B7-H1/genética , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/virologia , Proliferação de Células/efeitos dos fármacos , Anergia Clonal/efeitos dos fármacos , Células Clonais , Modelos Animais de Doenças , Regulação da Expressão Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Interações Hospedeiro-Patógeno/efeitos dos fármacos , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Coriomeningite Linfocítica/tratamento farmacológico , Coriomeningite Linfocítica/patologia , Coriomeningite Linfocítica/virologia , Vírus da Coriomeningite Linfocítica/efeitos dos fármacos , Vírus da Coriomeningite Linfocítica/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Nucleoproteínas/genética , Receptores de Antígenos de Linfócitos T/genética , Transdução de Sinais , Carga Viral
7.
Nature ; 583(7815): 296-302, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32612232

RESUMO

The mammalian immune system implements a remarkably effective set of mechanisms for fighting pathogens1. Its main components are haematopoietic immune cells, including myeloid cells that control innate immunity, and lymphoid cells that constitute adaptive immunity2. However, immune functions are not unique to haematopoietic cells, and many other cell types display basic mechanisms of pathogen defence3-5. To advance our understanding of immunology outside the haematopoietic system, here we systematically investigate the regulation of immune genes in the three major types of structural cells: epithelium, endothelium and fibroblasts. We characterize these cell types across twelve organs in mice, using cellular phenotyping, transcriptome sequencing, chromatin accessibility profiling and epigenome mapping. This comprehensive dataset revealed complex immune gene activity and regulation in structural cells. The observed patterns were highly organ-specific and seem to modulate the extensive interactions between structural cells and haematopoietic immune cells. Moreover, we identified an epigenetically encoded immune potential in structural cells under tissue homeostasis, which was triggered in response to systemic viral infection. This study highlights the prevalence and organ-specific complexity of immune gene activity in non-haematopoietic structural cells, and it provides a high-resolution, multi-omics atlas of the epigenetic and transcriptional networks that regulate structural cells in the mouse.


Assuntos
Endotélio/imunologia , Células Epiteliais/imunologia , Fibroblastos/imunologia , Regulação da Expressão Gênica/imunologia , Sistema Imunitário/citologia , Sistema Imunitário/imunologia , Especificidade de Órgãos/imunologia , Imunidade Adaptativa , Animais , Cromatina/genética , Cromatina/metabolismo , Endotélio/citologia , Epigênese Genética/imunologia , Epigenoma/genética , Células Epiteliais/citologia , Feminino , Fibroblastos/citologia , Regulação da Expressão Gênica/genética , Redes Reguladoras de Genes/genética , Redes Reguladoras de Genes/imunologia , Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/imunologia , Sistema Imunitário/virologia , Imunidade Inata , Coriomeningite Linfocítica/imunologia , Coriomeningite Linfocítica/virologia , Vírus da Coriomeningite Linfocítica/imunologia , Masculino , Camundongos , Especificidade de Órgãos/genética , Transcrição Genética/imunologia , Transcriptoma/genética
8.
PLoS Pathog ; 16(6): e1008555, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32579593

RESUMO

Exhaustion is a dysfunctional state of cytotoxic CD8+ T cells (CTL) observed in chronic infection and cancer. Current in vivo models of CTL exhaustion using chronic viral infections or cancer yield very few exhausted CTL, limiting the analysis that can be done on these cells. Establishing an in vitro system that rapidly induces CTL exhaustion would therefore greatly facilitate the study of this phenotype, identify the truly exhaustion-associated changes and allow the testing of novel approaches to reverse or prevent exhaustion. Here we show that repeat stimulation of purified TCR transgenic OT-I CTL with their specific peptide induces all the functional (reduced cytokine production and polyfunctionality, decreased in vivo expansion capacity) and phenotypic (increased inhibitory receptors expression and transcription factor changes) characteristics of exhaustion. Importantly, in vitro exhausted cells shared the transcriptomic characteristics of the gold standard of exhaustion, CTL from LCMV cl13 infections. Gene expression of both in vitro and in vivo exhausted CTL was distinct from T cell anergy. Using this system, we show that Tcf7 promoter DNA methylation contributes to TCF1 downregulation in exhausted CTL. Thus this novel in vitro system can be used to identify genes and signaling pathways involved in exhaustion and will facilitate the screening of reagents that prevent/reverse CTL exhaustion.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Metilação de DNA/imunologia , Fator 1-alfa Nuclear de Hepatócito/imunologia , Coriomeningite Linfocítica/imunologia , Vírus da Coriomeningite Linfocítica/imunologia , Regiões Promotoras Genéticas/imunologia , Animais , Linfócitos T CD8-Positivos/patologia , Fator 1-alfa Nuclear de Hepatócito/genética , Coriomeningite Linfocítica/genética , Coriomeningite Linfocítica/patologia , Vírus da Coriomeningite Linfocítica/genética , Camundongos , Camundongos Transgênicos , Transdução de Sinais/genética , Transdução de Sinais/imunologia
9.
Mol Immunol ; 124: 125-141, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32563081

RESUMO

Both mouse and human harbour memory phenotype CD8+ T cells specific for antigens in hosts that have not been previously exposed to these antigens. The origin and the nature of the stimuli responsible for generation of CD44hi CD8+ T cells in specific pathogen-free (SPF) mice remain controversial. It is known that microbiota plays a crucial role in the prevention and resolution of systemic infections by influencing myelopoiesis, regulating dendritic cells, inflammasome activation and promoting the production of type I and II interferons. By contrast, here we suggest that microbiota has a direct effect on generation of memory phenotype CD44hiGP33+CD8+ T cells. In SPF mice, it generates a novel GP33+CD44hiCD8+ T cell sub-population associating the properties of innate and genuine memory cells. These cells are highly enriched in the bone marrow, proliferate rapidly and express immediate effector functions. They dominate the response to LCMV and express particular TCRß chains. The sequence of these selected TCRß chains overlaps with that of GP33+CD8+ T cells directly selected by microbiota in the gut epithelium of SPF mice, demonstrating a common selection mechanism in gut and peripheral CD8+ T cell pool. Therefore microbiota has a direct role in priming T cell immunity in SPF mice and in the selection of TCRß repertoires during systemic infection. We identify a mechanism that primes T cell immunity in SPF mice and may have a major role in colonization resistance and protection from infection.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Coriomeningite Linfocítica/imunologia , Microbiota/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Animais , Citotoxicidade Imunológica/imunologia , Memória Imunológica/imunologia , Vírus da Coriomeningite Linfocítica/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Organismos Livres de Patógenos Específicos , Subpopulações de Linfócitos T/imunologia
10.
Immunity ; 52(5): 808-824.e7, 2020 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-32433949

RESUMO

Tissue-resident memory CD8+ T cells (Trm) provide host protection through continuous surveillance of non-lymphoid tissues. Using single-cell RNA-sequencing (scRNA-seq) and genetic reporter mice, we identified discrete lineages of intestinal antigen-specific CD8+ T cells, including a Blimp1hiId3lo tissue-resident effector cell population most prominent in the early phase of acute viral and bacterial infections and a molecularly distinct Blimp1loId3hi tissue-resident memory population that subsequently accumulated at later infection time points. These Trm populations exhibited distinct cytokine production, secondary memory potential, and transcriptional programs including differential roles for transcriptional regulators Blimp1, T-bet, Id2, and Id3 in supporting and maintaining intestinal Trm. Extending our analysis to malignant tissue, we also identified discrete populations of effector-like and memory-like CD8+ T cell populations with tissue-resident gene-expression signatures that shared features of terminally exhausted and progenitor-exhausted T cells, respectively. Our findings provide insight into the development and functional heterogeneity of Trm cells, which has implications for enhancing vaccination and immunotherapy approaches.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Memória Imunológica/imunologia , Coriomeningite Linfocítica/imunologia , Vírus da Coriomeningite Linfocítica/imunologia , Neoplasias/terapia , Animais , Linfócitos T CD8-Positivos/metabolismo , Linfócitos T CD8-Positivos/virologia , Células Cultivadas , Imunoterapia/métodos , Proteína 2 Inibidora de Diferenciação/genética , Proteína 2 Inibidora de Diferenciação/imunologia , Proteína 2 Inibidora de Diferenciação/metabolismo , Proteínas Inibidoras de Diferenciação/genética , Proteínas Inibidoras de Diferenciação/imunologia , Proteínas Inibidoras de Diferenciação/metabolismo , Coriomeningite Linfocítica/virologia , Vírus da Coriomeningite Linfocítica/fisiologia , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Neoplasias/imunologia , Fator 1 de Ligação ao Domínio I Regulador Positivo/genética , Fator 1 de Ligação ao Domínio I Regulador Positivo/imunologia , Fator 1 de Ligação ao Domínio I Regulador Positivo/metabolismo
11.
Nat Commun ; 11(1): 1632, 2020 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-32242021

RESUMO

Co-stimulatory signals, cytokines and transcription factors regulate the balance between effector and memory cell differentiation during T cell activation. Here, we analyse the role of the TRAF2-/NCK-interacting kinase (TNIK), a signaling molecule downstream of the tumor necrosis factor superfamily receptors such as CD27, in the regulation of CD8+ T cell fate during acute infection with lymphocytic choriomeningitis virus. Priming of CD8+ T cells induces a TNIK-dependent nuclear translocation of ß-catenin with consecutive Wnt pathway activation. TNIK-deficiency during T cell activation results in enhanced differentiation towards effector cells, glycolysis and apoptosis. TNIK signaling enriches for memory precursors by favouring symmetric over asymmetric cell division. This enlarges the pool of memory CD8+ T cells and increases their capacity to expand after re-infection in serial re-transplantation experiments. These findings reveal that TNIK is an important regulator of effector and memory T cell differentiation and induces a population of stem cell-like memory T cells.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Coriomeningite Linfocítica/imunologia , Proteínas Serina-Treonina Quinases/imunologia , Animais , Apoptose , Linfócitos T CD8-Positivos/citologia , Diferenciação Celular , Humanos , Memória Imunológica , Ativação Linfocitária , Coriomeningite Linfocítica/genética , Coriomeningite Linfocítica/fisiopatologia , Coriomeningite Linfocítica/virologia , Vírus da Coriomeningite Linfocítica/fisiologia , Camundongos , Camundongos Knockout , Proteínas Serina-Treonina Quinases/genética , Transdução de Sinais , Via de Sinalização Wnt
12.
PLoS Pathog ; 16(4): e1008525, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32310998

RESUMO

Signal transducers and activators of transcription (STAT) 1 is critical for cellular responses to type I interferons (IFN-Is), with the capacity to determine the outcome of viral infection. We previously showed that while wildtype (WT) mice develop mild disease and survive infection with lymphocytic choriomeningitis virus (LCMV), LCMV infection of STAT1-deficient mice results in a lethal wasting disease that is dependent on IFN-I and CD4+ cells. IFN-Is are considered to act as a bridge between innate and adaptive immunity. Here, we determined the relative contribution of STAT1 on innate and adaptive immunity during LCMV infection. We show that STAT1 deficiency results in a biphasic disease following LCMV infection. The initial, innate immunity-driven phase of disease was characterized by rapid weight loss, thrombocytopenia, systemic cytokine and chemokine responses and leukocyte infiltration of infected organs. In the absence of an adaptive immune response, this first phase of disease largely resolved resulting in survival of the infected host. However, in the presence of adaptive immunity, the disease progressed into a second phase with continued cytokine and chemokine production, persistent leukocyte extravasation into infected tissues and ultimately, host death. Overall, our findings demonstrate the key contribution of STAT1 in modulating innate and adaptive immunity during type I interferon-mediated lethal virus infection.


Assuntos
Coriomeningite Linfocítica/imunologia , Imunidade Adaptativa/imunologia , Animais , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Feminino , Imunidade Inata/imunologia , Interferon Tipo I/imunologia , Vírus da Coriomeningite Linfocítica/imunologia , Vírus da Coriomeningite Linfocítica/patogenicidade , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fator de Transcrição STAT1/imunologia , Fator de Transcrição STAT1/metabolismo , Transdução de Sinais , Viroses/imunologia , Replicação Viral
13.
Proc Natl Acad Sci U S A ; 117(10): 5420-5429, 2020 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-32094187

RESUMO

Chronic infection provokes alterations in inflammatory and suppressive pathways that potentially affect the function and integrity of multiple tissues, impacting both ongoing immune control and restorative immune therapies. Here we demonstrate that chronic lymphocytic choriomeningitis virus infection rapidly triggers severe thymic depletion, mediated by CD8 T cell-intrinsic type I interferon (IFN) and signal transducer and activator of transcription 2 (Stat2) signaling. Occurring temporal to T cell exhaustion, thymic cellularity reconstituted despite ongoing viral replication, with a rapid secondary thymic depletion following immune restoration by anti-programmed death-ligand 1 (PDL1) blockade. Therapeutic hematopoietic stem cell transplant (HSCT) during chronic infection generated new antiviral CD8 T cells, despite sustained virus replication in the thymus, indicating an impairment in negative selection. Consequently, low amounts of high-affinity self-reactive T cells also escaped the thymus following HSCT during chronic infection. Thus, by altering the stringency and partially impairing negative selection, the host generates new virus-specific T cells to replenish the fight against the chronic infection, but also has the potentially dangerous effect of enabling the escape of self-reactive T cells.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/virologia , Interferon Tipo I/metabolismo , Coriomeningite Linfocítica/imunologia , Coriomeningite Linfocítica/patologia , Vírus da Coriomeningite Linfocítica , Timo/patologia , Timo/virologia , Animais , Atrofia/virologia , Antígeno B7-H1/antagonistas & inibidores , Doença Crônica , Transplante de Células-Tronco Hematopoéticas , Interferon Tipo I/genética , Coriomeningite Linfocítica/terapia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Fator de Transcrição STAT2/metabolismo , Transdução de Sinais , Replicação Viral
14.
Proc Natl Acad Sci U S A ; 117(8): 4292-4299, 2020 02 25.
Artigo em Inglês | MEDLINE | ID: mdl-32034098

RESUMO

The migratory patterns of virus-specific CD8 T cells during chronic viral infection are not well understood. To address this issue, we have done parabiosis experiments during chronic lymphocytic choriomeningitis virus (LCMV) infection of mice. We found that despite the high frequency of virus-specific CD8 T cells in both lymphoid and nonlymphoid tissues there was minimal migration of virus-specific CD8 T cells between the chronically infected conjoined parabiont mice. This was in contrast to parabionts between mice that had undergone an acute LCMV infection where virus-specific CD8 T cells established equilibrium demonstrating circulation of memory T cells generated after viral clearance. We have identified a population of PD-1+ TCF1+CXCR5+Tim-3- stemlike virus-specific CD8 T cells that reside in lymphoid tissues and act as resource cells for maintaining the T cell response during chronic infection. These are the cells that proliferate and give rise to the more terminally differentiated PD-1+ CXCR5-Tim-3+ CD8 T cells. Both the stemlike CD8 T cells and their terminally differentiated progeny showed minimal migration during chronic infection and the few LCMV-specific CD8 T cells that were present in circulation were the recently emerging progeny from the stemlike CD8 T cells. The PD-1+ TCF1+CXCR5+ stemlike CD8 T cells were truly resident in lymphoid tissues and did not circulate in the blood. We propose that this residency in specialized niches within lymphoid tissues is a key aspect of their biology and is essential for maintaining their quiescence and stemlike program under conditions of a chronic viral infection.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Coriomeningite Linfocítica/imunologia , Vírus da Coriomeningite Linfocítica/fisiologia , Tecido Linfoide/imunologia , Receptor de Morte Celular Programada 1/imunologia , Animais , Feminino , Receptor Celular 2 do Vírus da Hepatite A/genética , Receptor Celular 2 do Vírus da Hepatite A/imunologia , Humanos , Memória Imunológica , Coriomeningite Linfocítica/genética , Coriomeningite Linfocítica/virologia , Vírus da Coriomeningite Linfocítica/genética , Tecido Linfoide/virologia , Camundongos , Camundongos Endogâmicos C57BL , Receptor de Morte Celular Programada 1/genética , Receptores CXCR5/genética , Receptores CXCR5/imunologia
15.
Cell Rep ; 30(4): 1013-1026.e7, 2020 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-31995746

RESUMO

Persistent viral infections subvert key elements of adaptive immunity. To compare germinal center (GC) B cell responses in chronic and acute lymphocytic choriomeningitis virus infection, we exploit activation-induced deaminase (AID) fate-reporter mice and perform adoptive B cell transfer experiments. Chronic infection yields GC B cell responses of higher cellularity than acute infections do, higher memory B cell and antibody secreting cell output for longer periods of time, a better representation of the late B cell repertoire in serum immunoglobulin, and higher titers of protective neutralizing antibodies. GC B cells of chronically infected mice are similarly hypermutated as those emerging from acute infection. They efficiently adapt to viral escape variants and even in hypermutation-impaired AID mutant mice, chronic infection selects for GC B cells with hypermutated B cell receptors (BCRs) and neutralizing antibody formation. These findings demonstrate that, unlike for CD8+ T cells, chronic viral infection drives a functional, productive, and protective GC B cell response.


Assuntos
Linfócitos B/imunologia , Centro Germinativo/imunologia , Coriomeningite Linfocítica/imunologia , Vírus da Coriomeningite Linfocítica/imunologia , Anticorpos de Domínio Único/genética , Doença Aguda , Animais , Anticorpos Neutralizantes/imunologia , Linfócitos B/metabolismo , Linfócitos T CD8-Positivos/imunologia , Linhagem Celular , Doença Crônica , Cricetinae , Citidina Desaminase/genética , Citidina Desaminase/metabolismo , Centro Germinativo/citologia , Sequenciamento de Nucleotídeos em Larga Escala , Região de Junção de Imunoglobulinas/genética , Imuno-Histoquímica , Coriomeningite Linfocítica/virologia , Vírus da Coriomeningite Linfocítica/patogenicidade , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Plasmócitos/imunologia , Hipermutação Somática de Imunoglobulina
16.
Cell Rep ; 30(4): 997-1012.e6, 2020 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-31995768

RESUMO

Control of established chronic lymphocytic choriomeningitis virus (LCMV) infection requires the production of neutralizing antibodies, but it remains unknown how the ensemble of antibodies evolves during ongoing infection. Here, we analyze the evolution of antibody responses during acute or chronic LCMV infection, combining quantitative functional assays and time-resolved antibody repertoire sequencing. We establish that antibody responses initially converge in both infection types on a functional and repertoire level, but diverge later during chronic infection, showing increased clonal diversity, the appearance of mouse-specific persistent clones, and distinct phylogenetic signatures. Chronic infection is characterized by a longer-lasting germinal center reaction and a continuous differentiation of plasma cells, resulting in the emergence of higher-affinity plasma cells exhibiting increased antibody secretion rates. Taken together, our findings reveal the emergence of a personalized antibody response in chronic infection and support the concept that maintaining B cell diversity throughout chronic LCMV infection correlates with the development of infection-resolving antibodies.


Assuntos
Anticorpos Antivirais/imunologia , Diversidade de Anticorpos/genética , Evolução Clonal/imunologia , Imunidade Humoral/genética , Coriomeningite Linfocítica/imunologia , Coriomeningite Linfocítica/virologia , Vírus da Coriomeningite Linfocítica/imunologia , Doença Aguda , Animais , Formação de Anticorpos/genética , Linfócitos B/imunologia , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Linhagem Celular , Doença Crônica , Evolução Clonal/genética , Centro Germinativo/metabolismo , Imunoglobulina G/imunologia , Vírus da Coriomeningite Linfocítica/patogenicidade , Camundongos , Camundongos Endogâmicos C57BL , Filogenia , Plasmócitos/imunologia , Plasmócitos/metabolismo , Hipermutação Somática de Imunoglobulina
17.
J Virol ; 94(5)2020 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-31776282

RESUMO

Chronic viral infections. like those of humans with cytomegalovirus, human immunodeficiency virus (even when under antiretroviral therapy), and hepatitis C virus or those of mice with lymphocytic choriomeningitis virus (LCMV) clone 13 (CL13), result in immune dysfunction that predisposes the host to severe infections with unrelated pathogens. It is known that C57BL/6 (B6) mice are resistant to mousepox, a lethal disease caused by the orthopoxvirus ectromelia virus (ECTV), and that this resistance requires natural killer (NK) cells and other immune cells. We show that most B6 mice chronically infected with CL13 succumb to mousepox but that most of those that recovered from acute infection with the LCMV Armstrong (Arm) strain survive. We also show that B6 mice chronically infected with CL13 and those that recovered from Arm infection have a reduced frequency and a reduced number of NK cells. However, at steady state, NK cells in mice that have recovered from Arm infection mature normally and, in response to ECTV, get activated, become more mature, proliferate, and increase their cytotoxicity in vivo Conversely, in mice chronically infected with CL13, NK cells are immature and residually activated, and following ECTV infection, they do not mature, proliferate, or increase their cytotoxicity. Given the well-established importance of NK cells in resistance to mousepox, these data suggest that the NK cell dysfunction caused by CL13 persistence may contribute to the susceptibility of CL13-infected mice to mousepox. Whether chronic infections similarly affect NK cells in humans should be explored.IMPORTANCE Infection of adult mice with the clone 13 (CL13) strain of lymphocytic choriomeningitis virus (LCMV) is extensively used as a model of chronic infection. In this paper, we show that mice chronically infected with CL13 succumb to challenge with ectromelia virus (ECTV; the agent of mousepox) and that natural killer (NK) cells in CL13-infected mice are reduced in numbers and have an immature and partially activated phenotype but do respond to ECTV. These data may provide additional clues why humans chronically infected with certain pathogens are less resistant to viral diseases.


Assuntos
Vírus da Ectromelia/imunologia , Ectromelia Infecciosa/imunologia , Células Matadoras Naturais/imunologia , Coriomeningite Linfocítica/imunologia , Membro 2 da Subfamília B de Transportadores de Cassetes de Ligação de ATP/genética , Animais , Citocinas/metabolismo , Modelos Animais de Doenças , Feminino , Vírus da Coriomeningite Linfocítica/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout
18.
Eur J Immunol ; 50(3): 396-403, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31724162

RESUMO

Persistent virus infections with non- or poorly cytopathic viruses are commonly associated with B cell dysregulations. These include the induction of hypergammaglobulinemia and the emergence of virus-unspecific antibodies. These seemingly unspecific antibody responses interfere with the virus-specific humoral immunity and contribute to delayed virus control. Whether these virus-unspecific antibodies are induced in the B cell follicle or at extrafollicular sites and whether one specific CD4 T cell subset is involved in the polyclonal B cell activation is unclear. Here we studied virus-unrelated IgG antibody responses against self or foreign antigens in the context of persistent lymphocytic choriomeningitis virus (LCMV) infection. We found that the LCMV-unspecific antibody response is short-lived and induced predominantly at extrafollicular sites and depends on the presence of LCMV-specific CD4 T cells. Our data support a scenario in which activated, virus-specific CD4 T cells provide help to non-specific B cells at extrafollicular sites, supporting the production of virus unspecific IgG antibodies during persistent viral infection.


Assuntos
Anticorpos Antivirais/imunologia , Linfócitos B/imunologia , Linfócitos T CD4-Positivos/imunologia , Ativação Linfocitária/imunologia , Coriomeningite Linfocítica/imunologia , Animais , Imunoglobulina G/imunologia , Vírus da Coriomeningite Linfocítica/imunologia , Camundongos Endogâmicos C57BL
19.
Virology ; 539: 26-37, 2020 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-31670188

RESUMO

In addition to direct anti-viral activity, NK cells regulate viral pathogenesis by virtue of their cytolytic attack on activated CD4 and CD8 T cells. To gain insight into which differentiated T cell subsets are preferred NK targets, transgenic T cells were differentiated in vitro into Th0, Th1, Th2, Th17, Treg, Tc1, and Tc2 effector cells and then tested for lysis by enriched populations of lymphocytic choriomeningitis virus (LCMV)-induced activated NK cells. There was a distinct hierarchy of cytotoxicity in vitro and in vivo, with Treg, Th17, and Th2 cells being more sensitive and Th0 and Th1 cells more resistant. Some distinctions between in vitro vs in vivo generated T cells were explainable by type 1 interferon induction of class 1 histocompatibility antigens on the effector T cell subsets. NK receptor (NKR)-deficient mice and anti-NKR antibody studies identified no one essential NKR for killing, though there could be redundancies.


Assuntos
Citotoxicidade Imunológica , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/virologia , Subpopulações de Linfócitos T/imunologia , Animais , Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/imunologia , Citotoxicidade Imunológica/efeitos dos fármacos , Interferons/genética , Interferons/farmacologia , Coriomeningite Linfocítica/imunologia , Vírus da Coriomeningite Linfocítica/imunologia , Vírus da Coriomeningite Linfocítica/patogenicidade , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Receptores de Células Matadoras Naturais/antagonistas & inibidores , Receptores de Células Matadoras Naturais/genética , Subpopulações de Linfócitos T/efeitos dos fármacos
20.
J Virol ; 94(5)2020 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-31826990

RESUMO

It is well established that chronic viral infections can cause immune suppression, resulting in increased susceptibility to other infectious diseases. However, the effects of chronic viral infection on T-cell responses and vaccination against highly pathogenic viruses are not well understood. We have recently shown that C57BL/6 (B6) mice lose their natural resistance to wild-type (WT) ectromelia virus (ECTV) when chronically infected with lymphocytic choriomeningitis virus (LCMV) clone 13 (CL13). Here we compared the T-cell response to ECTV in previously immunologically naive mice that were chronically infected with CL13 or that were convalescent from acute infection with the Armstrong (Arm) strain of LCMV. Our results show that mice that were chronically infected with CL13 but not those that had recovered from Arm infection have highly defective ECTV-specific CD8+ and CD4+ T-cell responses to WT ECTV. These defects are at least partly due to the chronic infection environment. In contrast to mice infected with WT ECTV, mice chronically infected with CL13 survived without signs of disease when infected with ECTV-Δ036, a mutant ECTV strain that is highly attenuated. Strikingly, mice chronically infected with CL13 mounted a strong CD8+ T-cell response to ECTV-Δ036 and survived without signs of disease after a subsequent challenge with WT ECTV. Our work suggests that enhanced susceptibility to acute viral infections in chronically infected individuals can be partly due to poor T-cell responses but that sufficient T-cell function can be recovered and resistance to acute infection can be restored by immunization with highly attenuated vaccines.IMPORTANCE Chronic viral infections may result in immunosuppression and enhanced susceptibility to infections with other pathogens. For example, we have recently shown that mice chronically infected with lymphocytic choriomeningitis virus (LCMV) clone 13 (CL13) are highly susceptible to mousepox, a disease that is caused by ectromelia virus and that is the mouse homolog of human smallpox. Here we show chronic CL13 infection severely disrupts the expansion, proliferation, activation, and cytotoxicity of T cells in response due at least in part to the suppressive effects of the chronic infection milieu. Notably, despite this profound immunodeficiency, mice chronically infected with CL13 could be protected by vaccination with a highly attenuated variant of ECTV. These results demonstrate that protective vaccination of immunosuppressed individuals is possible, provided that proper immunization tools are used.


Assuntos
Ectromelia Infecciosa/imunologia , Imunidade Inata/imunologia , Imunização , Coriomeningite Linfocítica/imunologia , Linfócitos T/imunologia , Animais , Linfócitos T CD8-Positivos/imunologia , Modelos Animais de Doenças , Vírus da Ectromelia/imunologia , Feminino , Humanos , Tolerância Imunológica , Memória Imunológica , Vírus da Coriomeningite Linfocítica/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Vacinação
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