RESUMO
Upon infection, naive CD8+ T cells differentiate into cytotoxic effector cells to eliminate the pathogen-infected cells. Although many mechanisms underlying this process have been demonstrated, the regulatory role of chromatin remodeling system in this process remains largely unknown. Here we show that BRD7, a component of the polybromo-associated BAF complex (PBAF), was required for naive CD8+ T cells to differentiate into functional short-lived effector cells (SLECs) in response to acute infections caused by influenza virus or lymphocytic choriomeningitis virus (LCMV). BRD7 deficiency in CD8+ T cells resulted in profound defects in effector population and functions, thereby impairing viral clearance and host recovery. Further mechanical studies indicate that the expression of BRD7 significantly turned to high from naive CD8+ T cells to effector cells, which bridged BRG1 and PBRM1 to the core module of PBAF complex, consequently facilitating the assembly of PBAF complex rather than BAF complex in the effector cells. The PBAF complex changed the chromatin accessibility at the loci of Tbx21 gene and upregulated its expression, leading to the maturation of effector T cells. Our research demonstrates that BRD7 and the PBAF complex are key in CD8+ T cell development and present a significant target for advancing immune therapies.
Assuntos
Linfócitos T CD8-Positivos , Diferenciação Celular , Proteínas Cromossômicas não Histona , Vírus da Coriomeningite Linfocítica , Animais , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Camundongos , Diferenciação Celular/imunologia , Diferenciação Celular/genética , Proteínas Cromossômicas não Histona/metabolismo , Proteínas Cromossômicas não Histona/genética , Vírus da Coriomeningite Linfocítica/imunologia , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteínas Nucleares/metabolismo , Proteínas Nucleares/genética , Camundongos Endogâmicos C57BL , Camundongos Knockout , Montagem e Desmontagem da Cromatina , Proteínas que Contêm BromodomínioRESUMO
Memory B cells are central to the establishment of immunological memory, providing long-term protection against specific pathogens and playing a vital role in the efficacy of vaccines. Understanding how memory B cell formation is disrupted during persistent infection is essential for new therapeutics. Lymphocytic choriomeningitis virus (LCMV) is an ideal model for investigating memory B cells in acute versus chronic infection. This protocol details techniques to isolate, enrich, and examine LCMV-specific memory B cells in both acute and chronic LCMV infection. Using an antigen tetramer enrichment system and flow cytometry, this method assesses low-frequency, polyclonal antigen-specific memory B cells.
Assuntos
Antígenos Virais , Citometria de Fluxo , Coriomeningite Linfocítica , Vírus da Coriomeningite Linfocítica , Células B de Memória , Vírus da Coriomeningite Linfocítica/imunologia , Animais , Camundongos , Coriomeningite Linfocítica/imunologia , Coriomeningite Linfocítica/virologia , Citometria de Fluxo/métodos , Antígenos Virais/imunologia , Células B de Memória/imunologia , Células B de Memória/metabolismo , Memória Imunológica , Linfócitos B/imunologia , Linfócitos B/metabolismoRESUMO
Lymphocytic choriomeningitis virus (LCMV) is an enveloped and segmented negative-sense RNA virus classified within the Arenaviridae family of the Bunyavirales order. LCMV is associated with fatal disease in immunocompromised populations and, as the prototypical arenavirus member, acts as a model for the many highly pathogenic members of the Arenaviridae family, such as Junín, Lassa, and Lujo viruses, all of which are associated with devastating hemorrhagic fevers. To enter cells, the LCMV envelope fuses with late endosomal membranes, for which two established requirements are low pH and interaction between the LCMV glycoprotein (GP) spike and secondary receptor CD164. LCMV subsequently uncoats, where the RNA genome-associated nucleoprotein (NP) separates from the Z protein matrix layer, releasing the viral genome into the cytosol. To further examine LCMV endosome escape, we performed an siRNA screen which identified host cell potassium ion (K+) channels as important for LCMV infection, with pharmacological inhibition confirming K+ channel involvement during the LCMV entry phase completely abrogating productive infection. To better understand the K+-mediated block in infection, we tracked incoming virions along their entry pathway under physiological conditions, where uncoating was signified by separation of NP and Z proteins. In contrast, K+ channel blockade prevented uncoating, trapping virions within Rab7 and CD164-positive endosomes, identifying K+ as a third LCMV entry requirement. K+ did not increase GP-CD164 binding or alter GP-CD164-dependent fusion. Thus, we propose that K+ mediates uncoating by modulating NP-Z interactions within the virion interior. These results suggest K+ channels represent a potential anti-arenaviral target.IMPORTANCEArenaviruses can cause fatal human disease for which approved preventative or therapeutic options are not available. Here, using the prototypical LCMV, we identified K+ channels as critical for arenavirus infection, playing a vital role during the entry phase of the infection cycle. We showed that blocking K+ channel function resulted in entrapment of LCMV particles within late endosomal compartments, thus preventing productive replication. Our data suggest K+ is required for LCMV uncoating and genome release by modulating interactions between the viral nucleoprotein and the matrix protein layer inside the virus particle.
Assuntos
Endossomos , Vírus da Coriomeningite Linfocítica , Potássio , Internalização do Vírus , Desenvelopamento do Vírus , Endossomos/virologia , Endossomos/metabolismo , Vírus da Coriomeningite Linfocítica/fisiologia , Vírus da Coriomeningite Linfocítica/genética , Humanos , Potássio/metabolismo , proteínas de unión al GTP Rab7 , Linhagem Celular , Animais , Canais de Potássio/metabolismo , Canais de Potássio/genéticaRESUMO
The proteasome generates the majority of peptides presented on MHC class I molecules. The cleavage pattern of the proteasome has been shown to be changed via the proteasome activator (PA)28 alpha beta (PA28αß). In particular, several immunogenic peptides have been reported to be PA28αß-dependent. In contrast, we did not observe a major impact of PA28αß on the generation of different major histocompatibility complex (MHC) classI ligands. PA28αß-knockout mice infected with the lymphocytic choriomeningitis virus (LCMV) or vaccinia virus showed a normal cluster of differentiation (CD) 8 response and viral clearance. However, we observed that the adoptive transfer of wild-type cells into PA28αß-knockout mice led to graft rejection, but not vice versa. Depletion experiments showed that the observed rejection was mediated by CD8+ cytotoxic T cells. These data indicate that PA28αß might be involved in the development of the CD8+ T cell repertoire in the thymus. Taken together, our data suggest that PA28αß is a crucial factor determining T cell selection and, therefore, impacts graft acceptance.
Assuntos
Linfócitos T CD8-Positivos , Rejeição de Enxerto , Antígenos de Histocompatibilidade Classe I , Camundongos Knockout , Animais , Rejeição de Enxerto/imunologia , Camundongos , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Antígenos de Histocompatibilidade Classe I/metabolismo , Antígenos de Histocompatibilidade Classe I/imunologia , Complexo de Endopeptidases do Proteassoma/metabolismo , Complexo de Endopeptidases do Proteassoma/imunologia , Ligantes , Camundongos Endogâmicos C57BL , Vírus da Coriomeningite Linfocítica/imunologia , Vaccinia virus/imunologiaRESUMO
Viral vectors are being used for the treatment of cancer. Yet, their efficacy varies among tumors and their use poses challenges in immunosuppressed patients, underscoring the need for alternatives. We report striking antitumoral effects by a nonlytic viral vector based on attenuated lymphocytic choriomeningitis virus (r3LCMV). We show in multiple tumor models that injection of tumor-bearing mice with this vector results in improved tumor control and survival. Importantly, r3LCMV improved tumor control in immunodeficient Rag1-/- mice and MyD88-/- mice, suggesting that multiple pathways contributed to the antitumoral effects. The antitumoral effects of r3LCMV were also observed when this vector was administered several weeks before tumor challenges, suggesting the induction of trained immunity. Single-cell RNA sequencing analyses, antibody blockade experiments, and knockout models revealed a critical role for host-intrinsic IFN-I in the antitumoral efficacy of r3LCMV vectors. Collectively, these data demonstrate potent antitumoral effects by r3LCMV vectors and unveil multiple mechanisms underlying their antitumoral efficacy.
Assuntos
Vetores Genéticos , Interferon Tipo I , Vírus da Coriomeningite Linfocítica , Camundongos Knockout , Animais , Vírus da Coriomeningite Linfocítica/imunologia , Vírus da Coriomeningite Linfocítica/genética , Camundongos , Interferon Tipo I/imunologia , Interferon Tipo I/genética , Fator 88 de Diferenciação Mieloide/genética , Fator 88 de Diferenciação Mieloide/imunologia , Humanos , Linhagem Celular Tumoral , Camundongos Endogâmicos C57BL , Neoplasias Experimentais/imunologia , Neoplasias Experimentais/genética , Neoplasias Experimentais/terapia , Neoplasias Experimentais/patologia , Proteínas de HomeodomínioRESUMO
The mammarenavirus Lassa virus (LASV) causes the life-threatening hemorrhagic fever disease, Lassa fever. The lack of licensed medical countermeasures against LASV underscores the urgent need for the development of novel LASV vaccines, which has been hampered by the requirement for a biosafety level 4 facility to handle live LASV. Here, we investigated the efficacy of mRNA-lipid nanoparticle (mRNA-LNP)-based vaccines expressing the LASV glycoprotein precursor (LASgpc) or nucleoprotein (LCMnp) of the prototypic mammarenavirus, lymphocytic choriomeningitis virus (LCMV), in mice. Two doses of LASgpc- or LCMnp-mRNA-LNP administered intravenously (i.v.) protected C57BL/6 mice from a lethal challenge with a recombinant (r) LCMV expressing a modified LASgpc (rLCMV/LASgpc2m) inoculated intracranially. Intramuscular (i.m.) immunization with two doses of LASgpc- or LCMnp-mRNA-LNP significantly reduced the viral load in C57BL/6 mice inoculated i.v. with rLCMV/LASgpc2m. High levels of viremia and lethality were observed in CBA mice inoculated i.v. with rLCMV/LASgpc2m, which were abrogated by i.m. immunization with two doses of LASgpc-mRNA-LNP. The protective efficacy of two i.m. doses of LCMnp-mRNA-LNP was confirmed in a lethal hemorrhagic disease model of FVB mice i.v. inoculated with wild-type rLCMV. In all conditions tested, negligible and high levels of LASgpc- and LCMnp-specific antibodies were detected in mRNA-LNP-immunized mice, respectively, but robust LASgpc- and LCMnp-specific CD8+ T cell responses were induced. Accordingly, plasma from LASgpc-mRNA-LNP-immunized mice did not exhibit neutralizing activity. Our findings and surrogate mouse models of LASV infection, which can be studied at a reduced biocontainment level, provide a critical foundation for the rapid development of mRNA-LNP-based LASV vaccines.IMPORTANCELassa virus (LASV) is a highly pathogenic mammarenavirus responsible for several hundred thousand infections annually in West African countries, causing a high number of lethal Lassa fever (LF) cases. Despite its significant impact on human health, clinically approved, safe, and effective medical countermeasures against LF are not available. The requirement of a biosafety level 4 facility to handle live LASV has been one of the main obstacles to the research and development of LASV countermeasures. Here, we report that two doses of mRNA-lipid nanoparticle-based vaccines expressing the LASV glycoprotein precursor (LASgpc) or nucleoprotein (LCMnp) of lymphocytic choriomeningitis virus (LCMV), a mammarenavirus genetically closely related to LASV, conferred protection to recombinant LCMV-based surrogate mouse models of lethal LASV infection. Notably, robust LASgpc- and LCMnp-specific CD8+ T cell responses were detected in mRNA-LNP-immunized mice, whereas no virus-neutralizing activity was observed.
Assuntos
Febre Lassa , Vírus Lassa , Vírus da Coriomeningite Linfocítica , Nanopartículas , Vacinas Virais , Animais , Feminino , Camundongos , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Modelos Animais de Doenças , Glicoproteínas/imunologia , Glicoproteínas/genética , Febre Lassa/prevenção & controle , Febre Lassa/imunologia , Vírus Lassa/imunologia , Vírus Lassa/genética , Lipossomos , Vírus da Coriomeningite Linfocítica/imunologia , Vírus da Coriomeningite Linfocítica/genética , Camundongos Endogâmicos C57BL , Nanopartículas/administração & dosagem , Nucleoproteínas/imunologia , Nucleoproteínas/genética , RNA Mensageiro/genética , RNA Mensageiro/imunologia , Carga Viral , Vacinas Virais/imunologia , Vacinas Virais/administração & dosagem , Vacinas Virais/genéticaRESUMO
Immunotherapy with checkpoint inhibitors, albeit commonly used against tumors, is still at its infancy against chronic virus infections. It relies on the reinvigoration of exhausted T lymphocytes to eliminate virus-infected cells. Since T cell exhaustion is a physiological process to reduce immunopathology, the reinvigoration of these cells might be associated with an augmentation of pathological changes. To test this possibility, we here analyzed in the model system of chronic lymphocytic choriomeningitis virus (LCMV)-infected mice whether treatment with the checkpoint inhibitor anti-PD-L1 antibody would increase CD8 T cell-dependent fibrosis. We show that pre-existing spleen fibrosis did not worsen under conditions that increase CD8 T cell functionality and reduce virus loads suggesting that the CD8 T cell functionality increase remained below its pathogenicity threshold. These promising findings should further encourage immunotherapeutic trials against chronic virus infections.
Assuntos
Antígeno B7-H1 , Linfócitos T CD8-Positivos , Fibrose , Inibidores de Checkpoint Imunológico , Imunoterapia , Coriomeningite Linfocítica , Vírus da Coriomeningite Linfocítica , Animais , Feminino , Camundongos , Antígeno B7-H1/antagonistas & inibidores , Antígeno B7-H1/imunologia , Linfócitos T CD8-Positivos/imunologia , Doença Crônica , Modelos Animais de Doenças , Inibidores de Checkpoint Imunológico/uso terapêutico , Inibidores de Checkpoint Imunológico/farmacologia , Coriomeningite Linfocítica/complicações , Coriomeningite Linfocítica/imunologia , Coriomeningite Linfocítica/terapia , Vírus da Coriomeningite Linfocítica/imunologia , Camundongos Endogâmicos C57BL , Baço/imunologia , Baço/virologia , Carga ViralRESUMO
Introduction: Macrophage function is determined by microenvironment and origin. Brain and retinal microglia are both derived from yolk sac progenitors, yet their microenvironments differ. Utilizing single-cell RNA sequencing (scRNA-seq) data from mice, we tested the hypothesis that retinal and brain microglia exhibit distinct transcriptional profiles due to their unique microenvironments. Methods: Eyes and brains from 2-4 month wildtype mice were combined (20 eyes; 3 brains) to yield one biologically diverse sample per organ. Each tissue was digested into single cell suspensions, enriched for immune cells, and sorted for scRNA-seq. Analysis was performed in Seurat v3 including clustering, integration, and differential expression. Multi-parameter flow cytometry was used for validation of scRNA-seq results. Lymphocytic choriomeningitis virus (LCMV) Clone 13, which produces a systemic, chronic, and neurotropic infection, was used to validate scRNA-seq and flow cytometry results in vivo. Results: Cluster analysis of integrated gene expression data from eye and brain identified 6 Tmem119 + P2ry12 + microglial clusters. Differential expression analysis revealed that eye microglia were enriched for more pro-inflammatory processes including antigen processing via MHC class I (14.0-fold, H2-D1 and H2-K1) and positive regulation of T-cell immunity (8.4-fold) compared to brain microglia. Multi-parameter flow cytometry confirmed that retinal microglia expressed 3.2-fold greater H2-Db and 263.3-fold more H2-Kb than brain microglia. On Day 13 and 29 after LCMV infection, CD8+ T-cell density was greater in the retina than the brain. Discussion: Our data demonstrate that the microenvironment of retina and brain differs, resulting in microglia-specific gene expression changes. Specifically, retinal microglia express greater MHC class I by scRNA-seq and multi-parameter flow cytometry, resulting in a possibly enhanced capability to stimulate CD8+ T-cell inflammation during LCMV infection. These results may explain tissue-specific differences between retina and brain during systemic viral infections and CD8+ T-cell driven autoimmune disease.
Assuntos
Encéfalo , Microglia , Retina , Animais , Microglia/imunologia , Microglia/metabolismo , Camundongos , Retina/imunologia , Retina/patologia , Encéfalo/imunologia , Encéfalo/patologia , Encéfalo/metabolismo , Camundongos Endogâmicos C57BL , Vírus da Coriomeningite Linfocítica/imunologia , Antígenos de Histocompatibilidade Classe I/genética , Antígenos de Histocompatibilidade Classe I/imunologia , Antígenos de Histocompatibilidade Classe I/metabolismo , Linfócitos T/imunologia , Inflamação/imunologia , Coriomeningite Linfocítica/imunologia , Coriomeningite Linfocítica/virologia , Análise de Célula Única , Linfócitos T CD8-Positivos/imunologia , TranscriptomaRESUMO
Follicular Helper T (TFH) cells are perceived as an independent CD4+ T cell lineage that assists cognate B cells in producing high-affinity antibodies, thus establishing long-term humoral immunity. During acute viral infection, the fate commitment of virus-specific TFH cells is determined in the early infection phase, and investigations of the early-differentiated TFH cells are crucial in understanding T cell-dependent humoral immunity and optimizing vaccine design. In the study, using a mouse model of acute lymphocytic choriomeningitis virus (LCMV) infection and the TCR-transgenic SMARTA (SM) mouse with CD4+ T cells specifically recognizing LCMV glycoprotein epitope I-AbGP66-77, we described procedures to access the early fate commitment of virus-specific TFH cells based on flow cytometry stainings. Furthermore, by exploiting retroviral transduction of SM CD4+ T cells, methods to manipulate gene expression in early-differentiated virus-specific TFH cells are also provided. Hence, these methods will help in studies exploring the mechanism(s) underlying the early commitment of virus-specific TFH cells.
Assuntos
Linfócitos T CD4-Positivos , Diferenciação Celular , Coriomeningite Linfocítica , Animais , Camundongos , Linfócitos T CD4-Positivos/imunologia , Diferenciação Celular/imunologia , Citometria de Fluxo/métodos , Coriomeningite Linfocítica/imunologia , Coriomeningite Linfocítica/virologia , Vírus da Coriomeningite Linfocítica/imunologia , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Células T Auxiliares Foliculares/imunologia , Linfócitos T Auxiliares-Indutores/imunologiaRESUMO
Memory B cells (MBCs) are key providers of long-lived immunity against infectious disease, yet in chronic viral infection, they do not produce effective protection. How chronic viral infection disrupts MBC development and whether such changes are reversible remain unknown. Through single-cell (sc)ATAC-seq and scRNA-seq during acute versus chronic lymphocytic choriomeningitis viral infection, we identified a memory subset enriched for interferon (IFN)-stimulated genes (ISGs) during chronic infection that was distinct from the T-bet+ subset normally associated with chronic infection. Blockade of IFNAR-1 early in infection transformed the chromatin landscape of chronic MBCs, decreasing accessibility at ISG-inducing transcription factor binding motifs and inducing phenotypic changes in the dominating MBC subset, with a decrease in the ISG subset and an increase in CD11c+CD80+ cells. However, timing was critical, with MBCs resistant to intervention at 4 weeks post-infection. Together, our research identifies a key mechanism to instruct MBC identity during viral infection.
Assuntos
Epigênese Genética , Interferon Tipo I , Coriomeningite Linfocítica , Vírus da Coriomeningite Linfocítica , Células B de Memória , Animais , Interferon Tipo I/metabolismo , Interferon Tipo I/imunologia , Coriomeningite Linfocítica/imunologia , Coriomeningite Linfocítica/virologia , Camundongos , Vírus da Coriomeningite Linfocítica/imunologia , Células B de Memória/imunologia , Camundongos Endogâmicos C57BL , Receptor de Interferon alfa e beta/genética , Memória Imunológica/imunologia , Doença Crônica , Subpopulações de Linfócitos B/imunologia , Análise de Célula ÚnicaRESUMO
In response to acute infection, naive CD4+ T cells primarily differentiate into T helper 1 (Th1) or T follicular helper (Tfh) cells that play critical roles in orchestrating cellular or humoral arms of immunity, respectively. However, despite the well established role of T-bet and BCL-6 in driving Th1 and Tfh cell lineage commitment, respectively, whether additional transcriptional circuits also underlie the fate bifurcation of Th1 and Tfh cell subsets is not fully understood. In this article, we study how the transcriptional regulator Bhlhe40 dictates the Th1/Tfh differentiation axis in mice. CD4+ T cell-specific deletion of Bhlhe40 abrogates Th1 but augments Tfh differentiation. We also assessed an increase in germinal center B cells and Ab production, suggesting that deletion of Bhlhe40 in CD4+ T cells not only alters Tfh differentiation but also their capacity to provide help to B cells. To identify molecular mechanisms by which Bhlhe40 regulates Th1 versus Tfh lineage choice, we first performed epigenetic profiling in the virus specific Th1 and Tfh cells following LCMV infection, which revealed distinct promoter and enhancer activities between the two helper cell lineages. Furthermore, we identified that Bhlhe40 directly binds to cis-regulatory elements of Th1-related genes such as Tbx21 and Cxcr6 to activate their expression while simultaneously binding to regions of Tfh-related genes such as Bcl6 and Cxcr5 to repress their expression. Collectively, our data suggest that Bhlhe40 functions as a transcription activator to promote Th1 cell differentiation and a transcription repressor to suppress Tfh cell differentiation.
Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos , Diferenciação Celular , Células T Auxiliares Foliculares , Células Th1 , Animais , Camundongos , Diferenciação Celular/imunologia , Diferenciação Celular/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Células T Auxiliares Foliculares/imunologia , Células Th1/imunologia , Camundongos Knockout , Camundongos Endogâmicos C57BL , Linfócitos B/imunologia , Coriomeningite Linfocítica/imunologia , Coriomeningite Linfocítica/virologia , Centro Germinativo/imunologia , Proteínas Proto-Oncogênicas c-bcl-6/genética , Proteínas Proto-Oncogênicas c-bcl-6/metabolismo , Vírus da Coriomeningite Linfocítica/imunologia , Receptores CXCR5/genética , Receptores CXCR5/metabolismo , Proteínas de HomeodomínioRESUMO
Lymphocytic choriomeningitis virus (LCMV) and Lassa virus (LASV) share many genetic and biological features including subtle differences between pathogenic and apathogenic strains. Despite remarkable genetic similarity, the viscerotropic WE strain of LCMV causes a fatal LASV fever-like hepatitis in non-human primates (NHPs) while the mouse-adapted Armstrong (ARM) strain of LCMV is deeply attenuated in NHPs and can vaccinate against LCMV-WE challenge. Here, we demonstrate that internalization of WE is more sensitive to the depletion of membrane cholesterol than ARM infection while ARM infection is more reliant on endosomal acidification. LCMV-ARM induces robust NF-κB and interferon response factor (IRF) activation while LCMV-WE seems to avoid early innate sensing and failed to induce strong NF-κB and IRF responses in dual-reporter monocyte and epithelial cells. Toll-like receptor 2 (TLR-2) signaling appears to play a critical role in NF-κB activation and the silencing of TLR-2 shuts down IL-6 production in ARM but not in WE-infected cells. Pathogenic LCMV-WE infection is poorly recognized in early endosomes and failed to induce TLR-2/Mal-dependent pro-inflammatory cytokines. Following infection, Interleukin-1 receptor-associated kinase 1 (IRAK-1) expression is diminished in LCMV-ARM- but not LCMV-WE-infected cells, which indicates it is likely involved in the LCMV-ARM NF-κB activation. By confocal microscopy, ARM and WE strains have similar intracellular trafficking although LCMV-ARM infection appears to coincide with greater co-localization of early endosome marker EEA1 with TLR-2. Both strains co-localize with Rab-7, a late endosome marker, but the interaction with LCMV-WE seems to be more prolonged. These findings suggest that LCMV-ARM's intracellular trafficking pathway may facilitate interaction with innate immune sensors, which promotes the induction of effective innate and adaptive immune responses.
Assuntos
Imunidade Inata , Vírus da Coriomeningite Linfocítica , Internalização do Vírus , Vírus da Coriomeningite Linfocítica/imunologia , Vírus da Coriomeningite Linfocítica/patogenicidade , Vírus da Coriomeningite Linfocítica/fisiologia , Animais , Humanos , Camundongos , Receptor 2 Toll-Like/metabolismo , Receptor 2 Toll-Like/genética , Endossomos/metabolismo , NF-kappa B/metabolismo , Transdução de Sinais , Linhagem Celular , Coriomeningite Linfocítica/imunologia , Coriomeningite Linfocítica/virologia , Células Epiteliais/virologia , Células Epiteliais/imunologiaRESUMO
BACKGROUND: Lymphocytic choriomeningitis virus (LCMV) belongs to the Arenavirus family known for inducing strong cytotoxic T-cell responses in both mice and humans. LCMV has been engineered for the development of cancer immunotherapies, currently undergoing evaluation in phase I/II clinical trials. Initial findings have demonstrated safety and an exceptional ability to activate and expand tumor-specific T lymphocytes. Combination strategies to maximize the antitumor effectiveness of LCMV-based immunotherapies are being explored. METHODS: We assessed the antitumor therapeutic effects of intratumoral administration of polyinosinic:polycytidylic acid (poly(I:C)) and systemic vaccination using an LCMV-vector expressing non-oncogenic versions of the E6 and E7 antigens of human papillomavirus 16 (artLCMV-E7E6) in a bilateral model engrafting TC-1/A9 cells. This cell line, derived from the parental TC-1, exhibits low MHC class I expression and is highly immune-resistant. The mechanisms underlying the combination's efficacy were investigated through bulk RNA-seq, flow cytometry analyses of the tumor microenvironment, selective depletions using antibodies and clodronate liposomes, Batf3 deficient mice, and in vivo bioluminescence experiments. Finally, we assessed the antitumor effectiveness of the combination of artLCMV-E7E6 with BO-112, a GMP-grade poly(I:C) formulated in polyethyleneimine, currently under evaluation in clinical trials. RESULTS: Intratumoral injection of poly(I:C) enhanced the antitumor efficacy of artLCMV-E7E6 in both injected and non-injected tumor lesions. The combined treatment resulted in a significant delay in tumor growth and often complete eradication of several tumor lesions, leading to significantly improved survival compared with monotherapies. While intratumoral administration of poly(I:C) did not impact LCMV vector biodistribution or transgene expression, it significantly modified leucocyte infiltrates within the tumor microenvironment and amplified systemic efficacy through proinflammatory cytokines/chemokines such as CCL3, CCL5, CXCL10, TNF, IFNα, and IL12p70. Upregulation of MHC on tumor cells and a reconfiguration of the gene expression programs related to tumor vasculature, leucocyte migration, and the activation profile of tumor-infiltrating CD8+ T lymphocytes were observed. Indeed, the antitumor effect relied on the functions of CD8+ T lymphocytes and macrophages. The synergistic efficacy of the combination was further confirmed when BO-112 was included. CONCLUSION: Intratumoral injection of poly(I:C) sensitizes MHClow tumors to the antitumor effects of artLCMV-E7E6, resulting in a potent therapeutic synergy.
Assuntos
Vírus da Coriomeningite Linfocítica , Neoplasias , Poli I-C , Animais , Humanos , Camundongos , Injeções Intralesionais , Distribuição Tecidual , Imunoterapia/métodos , Adjuvantes Imunológicos , Microambiente TumoralRESUMO
Blindness or vision loss due to neuroretinal and photoreceptor degeneration affects millions of individuals worldwide. In numerous neurodegenerative diseases, including age-related macular degeneration, dysregulated immune response-mediated retinal degeneration has been found to play a critical role in the disease pathogenesis. To better understand the pathogenic mechanisms underlying the retinal degeneration, we used a mouse model of systemic immune activation where we infected mice with lymphocytic choriomeningitis virus (LCMV) clone 13. Here, we evaluated the effects of LCMV infection and present a comprehensive discovery-based proteomic investigation using tandem mass tag (TMT) labeling and high-resolution liquid chromatography-tandem mass spectrometry (LC-MS/MS). Changes in protein regulation in the posterior part of the eye, neuroretina, and RPE/choroid were compared to those in the spleen as a secondary lymphoid organ and to the kidney as a non-lymphoid but encapsulated organ at 1, 8, and 28 weeks of infection. Using bioinformatic tools, we found several proteins responsible for maintaining normal tissue homeostasis to be differentially regulated in the neuroretina and the RPE/choroid during the degenerative process. Additionally, in the organs we observed, several important protein pathways contributing to cellular homeostasis and tissue development were perturbed and associated with LCMV-mediated inflammation, promoting disease progression. Our findings suggest that the response to a systemic chronic infection differs between the neuroretina and the RPE/choroid, and the processes induced by chronic systemic infection in the RPE/choroid are not unlike those induced in non-immune-privileged organs such as the kidney and spleen. Overall, our data provide detailed insight into several molecular mechanisms of neuroretinal degeneration and highlight various novel protein pathways that further suggest that the posterior part of the eye is not an isolated immunological entity despite the existence of neuroretinal immune privilege.
Assuntos
Modelos Animais de Doenças , Vírus da Coriomeningite Linfocítica , Proteômica , Degeneração Retiniana , Animais , Camundongos , Proteômica/métodos , Degeneração Retiniana/imunologia , Degeneração Retiniana/metabolismo , Degeneração Retiniana/patologia , Vírus da Coriomeningite Linfocítica/imunologia , Camundongos Endogâmicos C57BL , Coriomeningite Linfocítica/imunologia , Coriomeningite Linfocítica/virologia , Espectrometria de Massas em Tandem , Proteoma , Retina/imunologia , Retina/metabolismo , Retina/patologia , Cromatografia Líquida , Corioide/imunologia , Corioide/patologia , Corioide/metabolismoRESUMO
Resident memory T (TRM) cells have been recently established as an important subset of memory T cells that provide early and essential protection against reinfection in the absence of circulating memory T cells. Recent findings showing that TRM expand in vivo after repeated antigenic stimulation indicate that these memory T cells are not terminally differentiated. This suggests an opportunity for in vitro TRM expansion to apply in an immunotherapy setting. However, it has also been shown that TRM may not maintain their identity and form circulating memory T cells after in vivo restimulation. Therefore, we set out to determine how TRM respond to antigenic activation in culture. Using Listeria monocytogenes and LCMV infection models, we found that TRM from the intraepithelial compartment of the small intestine expand in vitro after antigenic stimulation and subsequent resting in homeostatic cytokines. A large fraction of the expanded TRM retained their phenotype, including the expression of key TRM markers CD69 and CD103 (ITGAE). The optimal culture of TRM required low O2 pressure to maintain the expression of these and other TRM-associated molecules. Expanded TRM retained their effector capacity to produce cytokines after restimulation, but did not acquire a highly glycolytic profile indicative of effector T cells. The proteomic analysis confirmed TRM profile retention, including expression of TRM-related transcription factors, tissue retention factors, adhesion molecules, and enzymes involved in fatty acid metabolism. Collectively, our data indicate that limiting oxygen conditions supports in vitro expansion of TRM cells that maintain their TRM phenotype, at least in part, suggesting an opportunity for therapeutic strategies that require in vitro expansion of TRM.
Assuntos
Memória Imunológica , Listeria monocytogenes , Células T de Memória , Animais , Células T de Memória/imunologia , Memória Imunológica/imunologia , Camundongos , Listeria monocytogenes/imunologia , Antígenos CD/metabolismo , Antígenos CD/imunologia , Cadeias alfa de Integrinas/metabolismo , Camundongos Endogâmicos C57BL , Listeriose/imunologia , Lectinas Tipo C/metabolismo , Lectinas Tipo C/imunologia , Antígenos de Diferenciação de Linfócitos T/imunologia , Antígenos de Diferenciação de Linfócitos T/metabolismo , Citocinas/metabolismo , Citocinas/imunologia , Ativação Linfocitária/imunologia , Vírus da Coriomeningite Linfocítica/imunologia , Mucosa Intestinal/imunologia , Linfócitos T CD8-Positivos/imunologia , Intestino Delgado/imunologia , Células CultivadasRESUMO
Immune cells rely on transient physical interactions with other immune and non-immune populations to regulate their function1. To study these 'kiss-and-run' interactions directly in vivo, we previously developed LIPSTIC (labelling immune partnerships by SorTagging intercellular contacts)2, an approach that uses enzymatic transfer of a labelled substrate between the molecular partners CD40L and CD40 to label interacting cells. Reliance on this pathway limited the use of LIPSTIC to measuring interactions between CD4+ T helper cells and antigen-presenting cells, however. Here we report the development of a universal version of LIPSTIC (uLIPSTIC), which can record physical interactions both among immune cells and between immune and non-immune populations irrespective of the receptors and ligands involved. We show that uLIPSTIC can be used, among other things, to monitor the priming of CD8+ T cells by dendritic cells, reveal the steady-state cellular partners of regulatory T cells and identify germinal centre-resident T follicular helper cells on the basis of their ability to interact cognately with germinal centre B cells. By coupling uLIPSTIC with single-cell transcriptomics, we build a catalogue of the immune populations that physically interact with intestinal epithelial cells at the steady state and profile the evolution of the interactome of lymphocytic choriomeningitis virus-specific CD8+ T cells in multiple organs following systemic infection. Thus, uLIPSTIC provides a broadly useful technology for measuring and understanding cell-cell interactions across multiple biological systems.
Assuntos
Linfócitos B , Linfócitos T CD8-Positivos , Comunicação Celular , Células Dendríticas , Células Epiteliais , Células T Auxiliares Foliculares , Linfócitos T Reguladores , Linfócitos T CD8-Positivos/citologia , Linfócitos T CD8-Positivos/imunologia , Comunicação Celular/imunologia , Células Dendríticas/citologia , Células Dendríticas/imunologia , Ligantes , Linfócitos T Reguladores/citologia , Linfócitos T Reguladores/imunologia , Células T Auxiliares Foliculares/citologia , Células T Auxiliares Foliculares/imunologia , Linfócitos B/citologia , Linfócitos B/imunologia , Centro Germinativo/citologia , Análise da Expressão Gênica de Célula Única , Células Epiteliais/citologia , Células Epiteliais/imunologia , Mucosa Intestinal/citologia , Mucosa Intestinal/imunologia , Vírus da Coriomeningite Linfocítica/imunologia , Coriomeningite Linfocítica/imunologia , Coriomeningite Linfocítica/virologia , Especificidade de ÓrgãosRESUMO
CD8+ T cells are critical to the adaptive immune response against viral pathogens. However, overwhelming antigen exposure can result in their exhaustion, characterised by reduced effector function, failure to clear virus, and the upregulation of inhibitory receptors, including programmed cell death 1 (PD-1). However, exhausted T cell responses can be "re-invigorated" by inhibiting PD-1 or the primary ligand of PD-1: PD-L1. Further, the absence of the type I interferon receptor IFNAR1 also results in T cell exhaustion and virus persistence in lymphocytic choriomeningitis virus Armstrong (LCMV-Arm)-infected mice. In this study, utilizing single- and double-knockout mice, we aimed to determine whether ablation of PD-1 could restore T cell functionality in the absence of IFNAR1 signalling in LCMV-Arm-infected mice. Surprisingly, this did not re-invigorate the T cell response and instead, it converted chronic LCMV-Arm infection into a lethal disease characterized by severe lung inflammation with an infiltration of neutrophils and T cells. Depletion of CD8+ T cells, but not neutrophils, rescued mice from lethal disease, demonstrating that IFNAR1 is required to prevent T cell exhaustion and virus persistence in LCMV-Arm infection, and in the absence of IFNAR1, PD-L1 is required for survival. This reveals an important interplay between IFNAR1 and PD-L1 with implications for therapeutics targeting these pathways.
Assuntos
Interferon Tipo I , Coriomeningite Linfocítica , Camundongos , Animais , Vírus da Coriomeningite Linfocítica , Linfócitos T CD8-Positivos , Antígeno B7-H1/genética , Antígeno B7-H1/metabolismo , Receptor de Morte Celular Programada 1/genética , Receptor de Morte Celular Programada 1/metabolismo , Camundongos Knockout , Interferon Tipo I/metabolismo , Camundongos Endogâmicos C57BLRESUMO
Chronic viral infections cause T cell dysfunction in both animal models and human clinical settings, thereby affecting the ability of the host immune system to clear viral pathogens and develop proper virus-specific immune memory. However, the impact of chronic viral infections on the host's immune memory to other pathogens has not been well described. In this study, we immunized mice with recombinant Listeria monocytogenes expressing OVA (Lm-OVA) to generate immunity to Lm and allow analysis of OVA-specific memory T (Tm) cells. We then infected these mice with lymphocytic choriomeningitis virus (LCMV) strain Cl-13 which establishes a chronic infection. We found that chronically infected mice were unable to protect against Listeria re-challenge. OVA-specific Tm cells showed a progressive loss in total numbers and in their ability to produce effector cytokines in the context of chronic LCMV infection. Unlike virus-specific T cells, OVA-specific Tm cells from chronically infected mice did not up-regulate the expression of inhibitory receptors, a hallmark feature of exhaustion in virus-specific T cells. Finally, OVA-specific Tm cells failed to mount a robust recall response after bacteria re-challenge both in the chronically infected and adoptively transferred naïve hosts. These results show that previously established bacteria-specific Tm cells become functionally impaired in the setting of an unrelated bystander chronic viral infection, which may contribute to poor immunity against other pathogens in the host with chronic viral infection.
Assuntos
Coriomeningite Linfocítica , Viroses , Humanos , Animais , Camundongos , Linfócitos T CD8-Positivos , Memória Imunológica , Vírus da Coriomeningite Linfocítica , Citocinas , Camundongos Endogâmicos C57BLRESUMO
Increased receptor binding affinity may allow viruses to escape from Ab-mediated inhibition. However, how high-affinity receptor binding affects innate immune escape and T cell function is poorly understood. In this study, we used the lymphocytic choriomeningitis virus (LCMV) murine infection model system to create a mutated LCMV exhibiting higher affinity for the entry receptor α-dystroglycan (LCMV-GPH155Y). We show that high-affinity receptor binding results in increased viral entry, which is associated with type I IFN (IFN-I) resistance, whereas initial innate immune activation was not impaired during high-affinity virus infection in mice. Consequently, IFN-I resistance led to defective antiviral T cell immunity, reduced type II IFN, and prolonged viral replication in this murine model system. Taken together, we show that high-affinity receptor binding of viruses can trigger innate affinity escape including resistance to IFN-I resulting in prolonged viral replication.
Assuntos
Coriomeningite Linfocítica , Internalização do Vírus , Camundongos , Animais , Camundongos Knockout , Vírus da Coriomeningite Linfocítica/fisiologia , Replicação Viral , Camundongos Endogâmicos C57BL , Imunidade InataRESUMO
Viral mimicry of host cell structures has been postulated to curtail the B cell receptor (BCR) repertoire against persisting viruses through tolerance mechanisms. This concept awaits, however, experimental testing in a setting of natural virus-host relationship. We engineered mouse models expressing a monoclonal BCR specific for the envelope glycoprotein of lymphocytic choriomeningitis virus (LCMV), a naturally persisting mouse pathogen. When the heavy chain of the LCMV-neutralizing antibody KL25 was paired with its unmutated ancestor light chain, most B cells underwent receptor editing, a behavior reminiscent of autoreactive clones. In contrast, monoclonal B cells expressing the same heavy chain in conjunction with the hypermutated KL25 light chain did not undergo receptor editing but exhibited low levels of surface IgM, suggesting that light chain hypermutation had lessened KL25 autoreactivity. Upon viral challenge, these IgMlow cells were not anergic but up-regulated IgM, participated in germinal center reactions, produced antiviral antibodies, and underwent immunoglobulin class switch as well as further affinity maturation. These studies on a persisting virus in its natural host species suggest that central tolerance mechanisms prune the protective antiviral B cell repertoire.