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An effective delivery platform is crucial for the development of mRNA vaccines and therapeutics. Here, a versatile platform utilizing cholesterol-modified oligonucleotides (L-oligo) that bind to the mRNA within lipid nanoparticles (LNP), and enables the effective delivery of the mRNA into target cells is introduced. mRNA incorporated into LNPs via linkage with L-oligo, termed oligonucleotide-linked LNP (lnLNP), is superior in cellular uptake and transfection efficiency in target cells in vitro and in vivo, compared to the conventional LNP formulations. It is further applied lnLNP as an mRNA vaccine platform for SARS-CoV-2, demonstrating robust induction of neutralizing activity as well as polyfunctional SARS-CoV-2-specific T-cell response in vivo. The current strategy can be versatilely applied to different LNP platforms, for vaccine and therapeutic applications against various diseases, such as infections and cancers.
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Replication stresses are the major source of break-induced replication (BIR). Here, we show that in alternative lengthening of telomeres (ALT) cells, replication stress-induced polyubiquitinated proliferating cell nuclear antigen (PCNA) (polyUb-PCNA) triggers BIR at telomeres and the common fragile site (CFS). Consistently, depleting RAD18, a PCNA ubiquitinating enzyme, reduces the occurrence of ALT-associated promyelocytic leukemia (PML) bodies (APBs) and mitotic DNA synthesis at telomeres and CFS, both of which are mediated by BIR. In contrast, inhibiting ubiquitin-specific protease 1 (USP1), an Ub-PCNA deubiquitinating enzyme, results in an increase in the above phenotypes in a RAD18- and UBE2N (the PCNA polyubiquitinating enzyme)-dependent manner. Furthermore, deficiency of ATAD5, which facilitates USP1 activity and unloads PCNAs, augments recombination-associated phenotypes. Mechanistically, telomeric polyUb-PCNA accumulates SLX4, a nuclease scaffold, at telomeres through its ubiquitin-binding domain and increases telomere damage. Consistently, APB increase induced by Ub-PCNA depends on SLX4 and structure-specific endonucleases. Taken together, our results identified the polyUb-PCNA-SLX4 axis as a trigger for directing BIR.
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ATPases Associadas a Diversas Atividades Celulares , Replicação do DNA , Proteínas de Ligação a DNA , Diester Fosfórico Hidrolases , Antígeno Nuclear de Célula em Proliferação , Homeostase do Telômero , Telômero , Ubiquitina-Proteína Ligases , Ubiquitinação , Humanos , Homeostase do Telômero/genética , Antígeno Nuclear de Célula em Proliferação/metabolismo , Antígeno Nuclear de Célula em Proliferação/genética , Telômero/metabolismo , Telômero/genética , Proteínas de Ligação a DNA/metabolismo , Proteínas de Ligação a DNA/genética , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitina-Proteína Ligases/genética , ATPases Associadas a Diversas Atividades Celulares/metabolismo , ATPases Associadas a Diversas Atividades Celulares/genética , Diester Fosfórico Hidrolases/metabolismo , Diester Fosfórico Hidrolases/genética , Enzimas de Conjugação de Ubiquitina/metabolismo , Enzimas de Conjugação de Ubiquitina/genética , Linhagem Celular Tumoral , Poliubiquitina/metabolismo , Poliubiquitina/genética , Proteases Específicas de Ubiquitina/metabolismo , Proteases Específicas de Ubiquitina/genética , RecombinasesRESUMO
Lamin A/C, a core component of the nuclear lamina, forms a mesh-like structure beneath the inner nuclear membrane. While its structural role is well-studied, its involvement in DNA metabolism remains unclear. We conducted sequential protein fractionation to determine the subcellular localization of early DNA damage response (DDR) proteins. Our findings indicate that most DDR proteins, including ATM and the MRE11-RAD50-NBS1 (MRN) complex, are present in the nuclease - and high salt-resistant pellet fraction. Notably, ATM and MRN remain stably associated with these structures throughout the cell cycle, independent of ionizing radiation (IR)-induced DNA damage. Although Lamin A/C interacts with ATM and MRN, its depletion does not disrupt their association with nuclease-resistant structures. However, it impairs the IR-enhanced association of ATM with the nuclear matrix and ATM-mediated DDR signaling, as well as the interaction between ATM and MRN. This disruption impedes the recruitment of MRE11 to damaged DNA and the association of damaged DNA with the nuclear matrix. Additionally, Lamin A/C depletion results in reduced protein levels of CtIP and RAD51, which is mediated by transcriptional regulation. This, in turn, impairs the efficiency of homologous recombination (HR). Our findings indicate that Lamin A/C plays a pivotal role in DNA damage repair (DDR) by orchestrating ATM-mediated signaling, maintaining HR protein levels, and ensuring efficient DNA repair processes.
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BACKGROUND: We aimed to investigate the distinct immunological characteristics of the tumor immune microenvironment in epithelial ovarian cancer (EOC) according to BRCA1/2 mutations status and differential PD-1 expression levels. METHODS: Tumor-infiltrating lymphocytes (TILs) were collected from patients with newly diagnosed advanced-stage EOC (YUHS cohort, n=117). This YUHS cohort was compared with The Cancer Genome Atlas (TCGA) data for ovarian serous cystadenocarcinoma (n=482), in terms of survival outcomes and immune-related gene profiles according to BRCA1/2 status. We used multicolor flow cytometry to characterize the immune phenotypes and heterogeneity of TILs with or without BRCA1/2 mutations. In vitro functional assays were conducted to evaluate the reinvigorating ability of CD8+ TILs on anti-PD-1 treatment. RESULTS: We found that EOC patients with BRCA1/2 mutations (BRCA1/2mt) exhibited better survival outcomes and significantly higher tumor mutation burden (TMB), compared with BRCA1/2 non-mutated (BRCA1/2wt) patients. Furthermore, CD8+ TILs within BRCA1/2mt tumors displayed characteristics indicating more severe T-cell exhaustion than their BRCA1/2wt counterparts. Notably, the capacity for anti-PD-1-mediated reinvigoration of CD8+ TILs was significantly greater in BRCA1/2wt tumors compared with BRCA1/2mt tumors. Additionally, within the BRCA1/2wt group, the frequency of PD-1highCD8+ TILs was positively correlated with the reinvigoration capacity of CD8+ TILs after anti-PD-1 treatment. CONCLUSION: Our results highlight unique immune features of CD8+ TILs in EOC and a differential response to anti-PD-1 treatment, contingent on BRCA1/2 mutation status. These findings suggest that immune checkpoint blockade may be a promising frontline therapeutic option for selected BRCA1/2wt EOC patients.
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Proteína BRCA1 , Linfócitos T CD8-Positivos , Carcinoma Epitelial do Ovário , Linfócitos do Interstício Tumoral , Mutação , Humanos , Feminino , Carcinoma Epitelial do Ovário/genética , Carcinoma Epitelial do Ovário/imunologia , Carcinoma Epitelial do Ovário/tratamento farmacológico , Linfócitos do Interstício Tumoral/imunologia , Linfócitos do Interstício Tumoral/metabolismo , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Proteína BRCA1/genética , Pessoa de Meia-Idade , Proteína BRCA2/genética , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/imunologia , Neoplasias Ovarianas/mortalidade , Inibidores de Checkpoint Imunológico/uso terapêutico , Inibidores de Checkpoint Imunológico/farmacologia , Adulto , Microambiente Tumoral/imunologia , IdosoRESUMO
Natural killer (NK) cells are a crucial component of the innate immune system. This study introduces Cellytics NK, a novel platform for rapid and precise measurement of NK cell activity. This platform combines an NK-specific activation stimulator cocktail (ASC) and lens-free shadow imaging technology (LSIT), using optoelectronic components. LSIT captures digital hologram images of resting and ASC-activated NK cells, while an algorithm evaluates cell size and cytoplasmic complexity using shadow parameters. The combined shadow parameter derived from the peak-to-peak distance and width standard deviation rapidly distinguishes active NK cells from inactive NK cells at the single-cell level within 30 s. Here, the feasibility of the system was demonstrated by assessing NK cells from healthy donors and immunocompromised cancer patients, demonstrating a significant difference in the innate immunity index (I3). Cancer patients showed a lower I3 value (161%) than healthy donors (326%). I3 was strongly correlated with NK cell activity measured using various markers such as interferon-gamma, tumor necrosis factor-alpha, perforin, granzyme B, and CD107a. This technology holds promise for advancing immune functional assays, offering rapid and accurate on-site analysis of NK cells, a crucial innate immune cell, with its compact and cost-effective optoelectronic setup, especially in the post-COVID-19 era.
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Técnicas Biossensoriais , Células Matadoras Naturais , Humanos , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/citologia , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Imunidade Inata , COVID-19/imunologia , COVID-19/virologia , Holografia/métodos , Holografia/instrumentação , Ativação Linfocitária , Interferon gama/análise , SARS-CoV-2/imunologia , SARS-CoV-2/isolamento & purificação , Neoplasias/imunologia , Neoplasias/diagnóstico por imagem , Granzimas , Fator de Necrose Tumoral alfa , Perforina/metabolismoRESUMO
BACKGROUND & AIMS: Chronic HCV infection results in abnormal immunological alterations, which are not fully normalized after viral elimination by direct-acting antiviral (DAA) treatment. Herein, we longitudinally examined phenotypic, transcriptomic, and epigenetic alterations in peripheral blood regulatory T (Treg) cells from patients with chronic HCV infection before, during, and after DAA treatment. METHODS: Patients with chronic genotype 1b HCV infection who achieved sustained virologic response by DAA treatment and age-matched healthy donors were recruited. Phenotypic characteristics of Treg cells were investigated through flow cytometry analysis. Moreover, the transcriptomic and epigenetic landscapes of Treg cells were analyzed using RNA sequencing and ATAC-seq (assay for transposase-accessible chromatin with sequencing) analysis. RESULTS: The Treg cell population - especially the activated Treg cell subpopulation - was expanded in peripheral blood during chronic HCV infection, and this expansion was sustained even after viral clearance. RNA sequencing analysis revealed that viral clearance did not abrogate the inflammatory features of these Treg cells, such as Treg activation and TNF signaling. Moreover, ATAC-seq analysis showed inflammatory imprinting in the epigenetic landscape of Treg cells from patients, which remained after treatment. These findings were further confirmed by intracellular cytokine staining, demonstrating that Treg cells exhibited inflammatory features and TNF production in chronic HCV infection that were maintained after viral clearance. CONCLUSIONS: Overall, our results showed that during chronic HCV infection, the expanded Treg cell population acquired inflammatory features at phenotypic, transcriptomic, and epigenetic levels, which were maintained even after successful viral elimination by DAA treatment. Further studies are warranted to examine the clinical significance of sustained inflammatory features in the Treg cell population after recovery from chronic HCV infection. IMPACT AND IMPLICATIONS: During chronic HCV infection, several immune components are altered both quantitatively and qualitatively. The recent introduction of direct-acting antivirals has led to high cure rates. Nevertheless, we have demonstrated that inflammatory features of Treg cells are maintained at phenotypic, transcriptomic, and epigenetic levels even after successful DAA treatment. Further in-depth studies are required to investigate the long-term clinical outcomes of patients who have recovered from chronic HCV infection.
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Antivirais , Epigênese Genética , Hepatite C Crônica , Linfócitos T Reguladores , Humanos , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/efeitos dos fármacos , Hepatite C Crônica/tratamento farmacológico , Hepatite C Crônica/imunologia , Hepatite C Crônica/virologia , Hepatite C Crônica/genética , Antivirais/uso terapêutico , Masculino , Pessoa de Meia-Idade , Feminino , Resposta Viral Sustentada , Hepacivirus/genética , Hepacivirus/efeitos dos fármacos , Hepacivirus/imunologia , AdultoRESUMO
Bispecific T cell engagers (TCEs) show promising clinical efficacy in blood tumors, but their application to solid tumors remains challenging. Here, we show that Fc-fused IL-7 (rhIL-7-hyFc) changes the intratumoral CD8 T cell landscape, enhancing the efficacy of TCE immunotherapy. rhIL-7-hyFc induces a dramatic increase in CD8 tumor-infiltrating lymphocytes (TILs) in various solid tumors, but the majority of these cells are PD-1-negative tumor non-responsive bystander T cells. However, they are non-exhausted and central memory-phenotype CD8 T cells with high T cell receptor (TCR)-recall capacity that can be triggered by tumor antigen-specific TCEs to acquire tumoricidal activity. Single-cell transcriptome analysis reveals that rhIL-7-hyFc-induced bystander CD8 TILs transform into cycling transitional T cells by TCE redirection with decreased memory markers and increased cytotoxic molecules. Notably, TCE treatment has no major effect on tumor-reactive CD8 TILs. Our results suggest that rhIL-7-hyFc treatment promotes the antitumor efficacy of TCE immunotherapy by increasing TCE-sensitive bystander CD8 TILs in solid tumors.
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Linfócitos T CD8-Positivos , Imunoterapia , Interleucina-7 , Linfócitos do Interstício Tumoral , Linfócitos do Interstício Tumoral/imunologia , Linfócitos do Interstício Tumoral/efeitos dos fármacos , Linfócitos T CD8-Positivos/imunologia , Interleucina-7/imunologia , Interleucina-7/metabolismo , Humanos , Animais , Imunoterapia/métodos , Camundongos , Neoplasias/imunologia , Neoplasias/terapia , Linhagem Celular Tumoral , Receptores de Antígenos de Linfócitos T/imunologia , Receptores de Antígenos de Linfócitos T/metabolismo , Efeito Espectador/imunologiaRESUMO
PURPOSE: To overcome the limited efficacy of immune checkpoint blockade, there is a need to find novel cancer immunotherapeutic strategies for the optimal treatment of cancer. The novel anti-4-1BB×PDL1 bispecific antibody-ABL503 (also known as TJ-L14B)-was designed to simultaneously target PDL1 and 4-1BB and demonstrated strong antitumor T-cell responses without considerable toxicity. In this study, we investigated the mechanisms by which the combination of ABL503 and anti-PD1 blockade affected the reinvigoration of exhausted tumor-infiltrating CD8+ T cells (CD8+ TIL) and antitumor efficacy. EXPERIMENTAL DESIGN: Single-cell suspensions of hepatocellular carcinoma and ovarian cancer tissues from treatment-naïve patients were used for immunophenotyping of CD8+ TILs and in vitro functional assays. Humanized hPD1/hPDL1/h4-1BB triple-knock-in mice were used to evaluate the effects of ABL503 and anti-PD1 blockade in vivo. RESULTS: We observed that ABL503 successfully restored the functions of 4-1BB+ exhausted CD8+ TILs, which were enriched for tumor-specific T cells but unresponsive to anti-PD1 blockade. Importantly, compared with anti-PD1 blockade alone, the combination of ABL503 and anti-PD1 blockade further enhanced the functional restoration of human CD8+ TILs in vitro. Consistently, the combination of ABL503 with anti-PD1 in vivo significantly alleviated tumor growth and induced enhanced infiltration and activation of CD8+ TILs. CONCLUSIONS: ABL503, a PDL1 and 4-1BB dual-targeting bispecific antibody, elicits pronounced additive tumor growth inhibition, with increased infiltration and functionality of exhausted CD8+ T cells, which in turn enhances the anticancer effects of anti-PD1 blockade. These promising findings suggest that ABL503 (TJ-L14B) in combination with PD1 inhibitors will likely further enhance therapeutic benefit in clinical trials. See related commentary by Molero-Glez et al., p. 3971.
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Anticorpos Biespecíficos , Linfócitos T CD8-Positivos , Inibidores de Checkpoint Imunológico , Linfócitos do Interstício Tumoral , Receptor de Morte Celular Programada 1 , Membro 9 da Superfamília de Receptores de Fatores de Necrose Tumoral , Anticorpos Biespecíficos/farmacologia , Anticorpos Biespecíficos/uso terapêutico , Linfócitos T CD8-Positivos/imunologia , Animais , Humanos , Camundongos , Feminino , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Receptor de Morte Celular Programada 1/imunologia , Linfócitos do Interstício Tumoral/imunologia , Linfócitos do Interstício Tumoral/efeitos dos fármacos , Membro 9 da Superfamília de Receptores de Fatores de Necrose Tumoral/antagonistas & inibidores , Membro 9 da Superfamília de Receptores de Fatores de Necrose Tumoral/imunologia , Inibidores de Checkpoint Imunológico/farmacologia , Inibidores de Checkpoint Imunológico/uso terapêutico , Antígeno B7-H1/antagonistas & inibidores , Antígeno B7-H1/imunologia , Ensaios Antitumorais Modelo de Xenoenxerto , Linhagem Celular Tumoral , Neoplasias Ovarianas/imunologia , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/patologia , Neoplasias Ovarianas/terapia , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/imunologia , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/terapia , Neoplasias Hepáticas/imunologia , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/patologiaRESUMO
IL-15 belongs to the common gamma chain cytokine family and has pleiotropic immunological functions. IL-15 is a homeostatic cytokine essential for the development and maintenance of NK cells and memory CD8+ T cells. In addition, IL-15 plays a critical role in the activation, effector functions, tissue residency, and senescence of CD8+ T cells. IL-15 also activates virtual memory T cells, mucosal-associated invariant T cells and γδ T cells. Recently, IL-15 has been highlighted as a major trigger of TCR-independent activation of T cells. This mechanism is involved in T cell-mediated immunopathogenesis in diverse diseases, including viral infections and chronic inflammatory diseases. Deeper understanding of IL-15-mediated T-cell responses and their underlying mechanisms could optimize therapeutic strategies to ameliorate host injury by T cell-mediated immunopathogenesis. This review highlights recent advancements in comprehending the role of IL-15 in relation to T cell responses and immunopathogenesis under various host conditions.
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The interferon-λ (IFN-λ)-regulated innate immune responses in the airway expand our understanding toward antiviral strategies against influenza A virus (IAV). The application of IFN-λ as mucosal antiviral therapeutic is still challenging, and advanced research will be necessary to achieve more efficient delivery of recombinant IFN-λs to the damaged respiratory mucosa. In this study, we examine the capability of IFN-λ to stimulate the innate immune response, promoting the swift elimination of IAV in the lungs. Additionally, we develop IFN-λ-loaded nanoparticles incorporated into pulmonary surfactant for inhalation therapy aimed at treating lung infections caused by IAV. We found that inhaled delivery of IFNλ-PSNPs significantly restricted IAV replication in the lungs from 3 days after infection (dpi), and IAV-caused lung histopathologic findings were completely improved in response to IFNλ-PSNPs. More significant and rapid attenuation of viral RNA was observed in the lung of mice with inhaled delivery of IFNλ-PSNPs compared to mice with recombinant IFN-λs. Inhalation treatment of IFNλ-PSNPs to IAV-infected mice can result in the increase of monocyte frequency in concert with restoration of T and B cells composition. Furthermore, the transcriptional profiles of monocytes shifted toward heightened IFN responses following IFNλ-PSNP treatment. These results imply that IFN-λ could serve as a robust inducer of innate immunity in the lungs against IAV infection, and inhalation of IFN-λs encapsulated in PSNPs effectively resolves lung infections caused by IAV through rapid viral clearance. PSNPs facilitated improved delivery of IFN-λs to the lungs, triggering potent antiviral immune responses upon IAV infection onset.
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Vírus da Influenza A , Influenza Humana , Surfactantes Pulmonares , Animais , Camundongos , Humanos , Interferon lambda , Imunidade Inata/genética , Pulmão/patologiaRESUMO
Here, we examine peripheral blood memory T cell responses against the SARS-CoV-2 BA.4/BA.5 variant spike among vaccinated individuals with or without Omicron breakthrough infections. We provide evidence supporting a lack of original antigenic sin in CD8+ T cell responses targeting the spike. We show that BNT162b2-induced memory T cells respond to the BA.4/BA.5 spike. Among individuals with BA.1/BA.2 breakthrough infections, IFN-γ-producing CD8+ T cell responses against the BA.4/BA.5 spike increased. In a subgroup with BA.2 breakthrough infections, IFN-γ-producing CD8+ T cell responses against the BA.2-mutated spike region increased and correlated directly with responses against the BA.4/BA.5 spike, indicating that BA.2 spike-specific CD8+ T cells elicited by BA.2 breakthrough infection cross-react with the BA.4/BA.5 spike. We identified CD8+ T cell epitope peptides that are present in the spike of BA.2 and BA.4/BA.5 but not the original spike. These peptides are fully conserved in the spike of now-dominant XBB lineages. Our study shows that breakthrough infection by early Omicron subvariants elicits CD8+ T cell responses that recognize epitopes within the spike of newly emerging subvariants.
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Vacina BNT162 , Linfócitos T CD8-Positivos , Humanos , Infecções Irruptivas , Epitopos de Linfócito T , PeptídeosRESUMO
BACKGROUND: Poly (adenosine diphosphate [ADP]-ribose) polymerase inhibitors (PARPis) are becoming the standard of care for epithelial ovarian cancer (EOC). Recently, clinical trials of triple maintenance therapy (PARPi+anti-angiogenic agent+anti-PD-1/L1) are actively ongoing. Here, we investigated the immunological effects of PARPi or triple maintenance therapy on T cells and their impact on clinical responses. METHODS: We collected serial blood from EOC patients receiving PARPi therapy (cohort 1: PARPi, n = 49; cohort 2: olaparib+bevacizumab+pembrolizumab, n = 31). Peripheral T cells were analyzed using flow cytometry and compared according to the PARPi response. Progression-free survival (PFS) was assessed according to prognostic biomarkers identified in a comparative analysis. RESULTS: Regulatory T cells (Tregs) were suppressed by PARPi therapy, whereas PD-1 was not significantly changed. Short PFS group exhibited a higher percentage of baseline PD-1+Tregs than long PFS group, and the patients with high percentage of PD-1+Tregs before treatment showed poor PFS in cohort 1. However, the expression of PD-1 on Tregs significantly decreased after receiving triple maintenance therapy, and the reduction in PD-1+Tregs was associated with superior PFS in cohort 2 (P = 0.0078). CONCLUSION: PARPi suppresses Tregs, but does not affect PD-1 expression. Adding anti-PD-1 to PARPi decreases PD-1+Tregs, which have negative prognostic value for PARPi monotherapy.
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Antineoplásicos , Neoplasias Ovarianas , Humanos , Feminino , Carcinoma Epitelial do Ovário/tratamento farmacológico , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Neoplasias Ovarianas/tratamento farmacológico , Receptor de Morte Celular Programada 1/uso terapêutico , Linfócitos T Reguladores , Antineoplásicos/uso terapêutico , Poli(ADP-Ribose) PolimerasesRESUMO
Homologous recombination (HR) requires bidirectional end resection initiated by a nick formed close to a DNA double-strand break (DSB), dysregulation favoring error-prone DNA end-joining pathways. Here we investigate the role of the ATAD5, a PCNA unloading protein, in short-range end resection, long-range resection not being affected by ATAD5 deficiency. Rapid PCNA loading onto DNA at DSB sites depends on the RFC PCNA loader complex and MRE11-RAD50-NBS1 nuclease complexes bound to CtIP. Based on our cytological analyses and on an in vitro system for short-range end resection, we propose that PCNA unloading by ATAD5 is required for the completion of short-range resection. Hampering PCNA unloading also leads to failure to remove the KU70/80 complex from the termini of DSBs hindering DNA repair synthesis and the completion of HR. In line with this model, ATAD5-depleted cells are defective for HR, show increased sensitivity to camptothecin, a drug forming protein-DNA adducts, and an augmented dependency on end-joining pathways. Our study highlights the importance of PCNA regulation at DSB for proper end resection and HR.
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Quebras de DNA de Cadeia Dupla , Reparo do DNA , DNA/metabolismo , Reparo do DNA por Junção de Extremidades , Endodesoxirribonucleases/metabolismo , Recombinação Homóloga/genética , Antígeno Nuclear de Célula em Proliferação/genética , Antígeno Nuclear de Célula em Proliferação/metabolismo , HumanosRESUMO
IMPORTANCE: Dabie bandavirus (DBV) is an emerging tick-borne virus that causes severe fever with thrombocytopenia syndrome (SFTS) in infected patients. Human SFTS symptoms progress from fever, fatigue, and muscle pain to the depletion of white blood cells and platelets with fatality rates up to 30%. The recent spread of its vector tick to over 20 states in the United States increases the potential for outbreaks of the SFTS beyond the East Asia. Thus, the development of vaccine to control this rapidly emerging virus is a high priority. In this study, we applied self-assembling ferritin (FT) nanoparticle to enhance the immunogenicity of DBV Gn head domain (GnH) as a vaccine target. Mice immunized with the GnH-FT nanoparticle vaccine induced potent antibody responses and cellular immunity. Immunized aged ferrets were fully protected from the lethal challenge of DBV. Our study describes the GnH-FT nanoparticle vaccine candidate that provides protective immunity against the emerging DBV infection.
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Furões , Febre Grave com Síndrome de Trombocitopenia , Humanos , Animais , Camundongos , Idoso , Nanovacinas , Modelos Animais de Doenças , FerritinasRESUMO
Dabie Bandavirus (DBV), previously known as Severe Fever with Thrombocytopenia Syndrome (SFTS) Virus, induces a characteristic thrombocytopenia with a mortality rate ranging from 12% to as high as 30%. The sero-prevalence of DBV in healthy people is not significantly different among age groups, but clinically diagnosed SFTS patients are older than ~50 years, suggesting that age is the critical risk factor for SFTS morbidity and mortality. Accordingly, our immune-competent ferret model demonstrates an age (>4 years old)-dependent DBV infection and pathogenesis that fully recapitulates human clinical manifestation. To protect the aged population from DBV-induced SFTS, vaccine should carry robust immunogenicity with high safety profile. Previous studies have shown that glycoproteins Gn/Gc are the most effective antigens for inducing both neutralizing antibody (NAb)- and T cell-mediated immunity and, thereby, protection. Here, we report the development of a protein subunit vaccine with 24-mer self-assembling ferritin (FT) nanoparticle to present DBV Gn head region (GnH) for enhanced immunogenicity. Anion exchange chromatography and size exclusion chromatography readily purified the GnH-FT nanoparticles to homogeneity with structural integrity. Mice immunized with GnH-FT nanoparticles induced robust NAb response and T-cell immunity against DBV Gn. Furthermore, aged ferrets immunized with GnH-FT nanoparticles were fully protected from DBV challenge without SFTS symptoms such as body weight loss, thrombocytopenia, leukopenia, and fatality. This study demonstrates that DBV GnH-FT nanoparticles provide an efficient vaccine efficacy in mouse and aged ferret models and should be an outstanding vaccine candidate targeted for the aged population against fatal DBV infection.
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Virtual memory T (TVM) cells are a T cell subtype with a memory phenotype but no prior exposure to foreign antigen. Although TVM cells have antiviral and antibacterial functions, whether these cells can be pathogenic effectors of inflammatory disease is unclear. Here we identified a TVM cell-originated CD44super-high(s-hi)CD49dlo CD8+ T cell subset with features of tissue residency. These cells are transcriptionally, phenotypically and functionally distinct from conventional CD8+ TVM cells and can cause alopecia areata. Mechanistically, CD44s-hiCD49dlo CD8+ T cells could be induced from conventional TVM cells by interleukin (IL)-12, IL-15 and IL-18 stimulation. Pathogenic activity of CD44s-hiCD49dlo CD8+ T cells was mediated by NKG2D-dependent innate-like cytotoxicity, which was further augmented by IL-15 stimulation and triggered disease onset. Collectively, these data suggest an immunological mechanism through which TVM cells can cause chronic inflammatory disease by innate-like cytotoxicity.
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Alopecia em Áreas , Linfócitos T CD8-Positivos , Humanos , Interleucina-15 , Memória Imunológica , Subpopulações de Linfócitos TRESUMO
Although CD4+CD25+FOXP3+ regulatory T (TREG) cells have been studied in patients with COVID-19, changes in the TREG cell population have not been longitudinally examined during the course of COVID-19. In this study, we longitudinally investigated the quantitative and qualitative changes in the TREG cell population in patients with COVID-19. We found that the frequencies of total TREG cells and CD45RA-FOXP3hi activated TREG cells were significantly increased 15-28 d postsymptom onset in severe patients, but not in mild patients. TREG cells from severe patients exhibited not only increased proliferation but also enhanced apoptosis, suggesting functional derangement of the TREG cell population during severe COVID-19. The suppressive functions of the TREG cell population did not differ between patients with severe versus mild COVID-19. The frequency of TREG cells inversely correlated with SARS-CoV-2-specific cytokine production by CD4+ T cells and their polyfunctionality in patients with mild disease, suggesting that TREG cells are major regulators of virus-specific CD4+ T cell responses during mild COVID-19. However, such correlations were not observed in patients with severe disease. Thus, in this study, we describe distinctive changes in the TREG cell population in patients with severe and mild COVID-19. Our study provides a deep understanding of host immune responses upon SARS-CoV-2 infection in regard to TREG cells.
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COVID-19 , Linfócitos T Reguladores , Humanos , SARS-CoV-2 , Linfócitos T CD4-Positivos , Subunidade alfa de Receptor de Interleucina-2 , Fatores de Transcrição ForkheadRESUMO
Memory T cells that mediate fast and effective protection against reinfections are usually generated upon recognition on foreign Ags. However, a "memory-like" T-cell population, termed virtual memory T (TVM) cells that acquire a memory phenotype in the absence of foreign Ag, has been reported. Although, like innate cells, TVM cells reportedly play a role in first-line defense to bacterial or viral infections, their protective or pathological roles in immune-related diseases are largely unknown. In this review, we discuss the current understanding of TVM cells, focusing on their distinct characteristics, immunological properties, and roles in various immune-related diseases, such as infections and cancers.