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1.
Artigo em Inglês | MEDLINE | ID: mdl-38720612

RESUMO

Backgrounds/Aims: The hepatocellular carcinoma (HCC) with portal vein tumor thrombosis (PVTT) is classified as the advanced stage (BCLC stage C) with extremely poor prognosis, and in current guidelines is recommended for systemic therapy. This study aimed to evaluate the surgical outcomes and long-term prognosis after hepatic resection (HR) for patients who have HCC combined with PVTT. Methods: We retrospectively analyzed 332 patients who underwent HR for HCC with PVTT at ten tertiary referral hospitals in South Korea. Results: The median overall and recurrence-free survival after HR were 32.4 and 8.6 months, while the 1-, 3-, and 5-year overall survival rates were 75%, 48%, and 39%, respectively. In multivariate analysis, tumor number, tumor size, AFP, PIVKA-II, neutrophil-to-lymphocyte ratio, and albumin-bilirubin (ALBI) grade were significant prognostic factors. The risk scoring was developed using these seven factors-tumor, inflammation and hepatic function (TIF), to predict patient prognosis. The prognosis of the patients was well stratified according to the scores (log-rank test, p < 0.001). Conclusions: HR for patients who have HCC combined with PVTT provided favorable survival outcomes. The risk scoring was useful in predicting prognosis, and determining the appropriate treatment strategy for those patients who have HCC with PVTT.

2.
Front Immunol ; 14: 1307693, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38143750

RESUMO

Introduction: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), had a major impact on both the global health and economy. Numerous virus-neutralizing antibodies were developed against the S1 subunit of SARS-CoV-2 spike (S) protein to block viral binding to host cells and were authorized for control of the COVID-19 pandemic. However, frequent mutations in the S1 subunit of SARS-CoV-2 enabled the emergence of immune evasive variants. To address these challenges, broadly neutralizing antibodies targeting the relatively conserved S2 subunit and its epitopes have been investigated as antibody therapeutics and universal vaccines. Methods: We initiated this study by immunizing BALB/c mice with ß-propiolactone-inactivated SARS-CoV-2 (IAV) to generate B-cell hybridomas. These hybridomas were subsequently screened using HEK293T cells expressing the S2-ECD domain. Hybridomas that produced anti-S2 antibodies were selected, and we conducted a comprehensive evaluation of the potential of these anti-S2 antibodies as antiviral agents and versatile tools for research and diagnostics. Results: In this study, we present a novel S2-specific antibody, 4A5, isolated from BALB/c mice immunized with inactivated SARS-CoV-2. 4A5 exhibited specific affinity to SARS-CoV-2 S2 subunits compared with those of other ß-CoVs. 4A5 bound to epitope segment F1109-V1133 between the heptad-repeat1 (HR1) and the stem-helix (SH) region. The 4A5 epitope is highly conserved in SARS-CoV-2 variants, with a significant conformational feature in both pre- and postfusion S proteins. Notably, 4A5 exhibited broad neutralizing activity against variants and triggered Fc-enhanced antibody-dependent cellular phagocytosis. Discussion: These findings offer a promising avenue for novel antibody therapeutics and insights for next-generation vaccine design. The identification of 4A5, with its unique binding properties and broad neutralizing capacity, offers a potential solution to the challenge posed by SARS-CoV-2 variants and highlights the importance of targeting the conserved S2 subunit in combating the COVID-19.


Assuntos
COVID-19 , SARS-CoV-2 , Animais , Camundongos , Humanos , SARS-CoV-2/genética , Anticorpos Antivirais , Pandemias , Células HEK293 , Epitopos
3.
Cell Rep ; 42(11): 113358, 2023 11 28.
Artigo em Inglês | MEDLINE | ID: mdl-37917584

RESUMO

Stress granules (SGs) constitute a signaling hub that plays a critical role in type I interferon responses. Here, we report that growth arrest and DNA damage-inducible beta (Gadd45ß) act as a positive regulator of SG-mediated interferon signaling by targeting G3BP upon RNA virus infection. Gadd45ß deficiency markedly impairs SG formation and SG-mediated activation of interferon signaling in vitro. Gadd45ß knockout mice are highly susceptible to RNA virus infection, and their ability to produce interferon and cytokines is severely impaired. Specifically, Gadd45ß interacts with the RNA-binding domain of G3BP, leading to conformational expansion of G3BP1 via dissolution of its autoinhibitory electrostatic intramolecular interaction. The acidic loop 1- and RNA-binding properties of Gadd45ß markedly increase the conformational expansion and RNA-binding affinity of the G3BP1-Gadd45ß complex, thereby promoting assembly of SGs. These findings suggest a role for Gadd45ß as a component and critical regulator of G3BP1-mediated SG formation, which facilitates RLR-mediated interferon signaling.


Assuntos
Interferon Tipo I , Infecções por Vírus de RNA , Animais , Camundongos , Grânulos Citoplasmáticos/metabolismo , DNA Helicases/metabolismo , Proteínas de Ligação a Poli-ADP-Ribose/genética , RNA , RNA Helicases/metabolismo , Proteínas com Motivo de Reconhecimento de RNA/genética , Grânulos de Estresse
4.
World J Gastrointest Surg ; 15(7): 1340-1353, 2023 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-37555110

RESUMO

BACKGROUND: Patients with combined hepatocellular carcinoma and cholangiocarcinoma (cHCC-CC) are not traditionally considered eligible for liver transplantation (LT) due to poor outcomes. AIM: To compare outcomes between living donor LT (LDLT) patients with hepatocellular carcinoma (HCC) and LT patients with cHCC-CC and to identify risk factors for tumor recurrence and death after LT in cHCC-CC patients. METHODS: Data for pathologically diagnosed cHCC-CC patients (n = 111) who underwent LT from 2000 to 2018 were collected for a nine-center retrospective review. Patients (n = 141) who received LDLT for HCC at Samsung Medical Center from January 2013 to March 2017 were selected as the control group. Seventy patients in two groups, respectively, were selected by 1:1 matching. RESULTS: Cumulative disease-free survival (DFS) and overall survival (OS) in the cHCC-CC group were significantly worse than in the HCC group both before and after matching. Extrahepatic recurrence incidence in the cHCC-CC group was higher than that in the HCC group (75.5% vs 33.3%, P < 0.001). Multivariate analysis demonstrated that the cHCC-CC group had significantly higher rates of tumor recurrence and death compared to the HCC group. In cHCC-CC subgroup analysis, frequency of locoregional therapies > 3, tumor size > 3 cm, and lymph node metastasis were predisposing factors for tumor recurrence in multivariate analysis. Only a maximum tumor size > 3 cm was a predisposing factor for death. CONCLUSION: The poor prognosis of patients diagnosed with cHCC-CC after LT can be predicted based on the explanted liver. Frequent regular surveillance for cHCC-CC patients should be required for early detection of tumor recurrence.

5.
NPJ Vaccines ; 8(1): 120, 2023 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-37580335

RESUMO

The mucosal delivery route is considered ideal for immunization. However, induction of antigen-specific mucosal immunity is difficult due to the tolerogenic environment. Therefore, developing an immunogenic mucosal dendritic cell (DC)-targeting strategy is required. Herein, we investigated the characteristics and immunogenic potential of Peyer's patch (PP) DCs as an oral vaccination-targeting strategy. Single-cell RNA sequencing analysis of the PP DCs showed that complement C5a receptor- and lysozyme-expressing DCs exhibit increased expression of genes related to chemotaxis. Administration of the Co1 peptide, a C5aR ligand, increased CD8+ T cell infiltration and response to the co-delivered model antigen in mice. Furthermore, in the SARS-CoV-2 vaccine model, vaccination with Co1 elicited both systemic and mucosal immunity. Collectively, these findings demonstrate that C5aR signaling in mucosal DCs plays a role in regulating adjuvant activity by modulating the tissue microenvironment.

6.
Immune Netw ; 23(2): e19, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37179748

RESUMO

Endemic human coronaviruses (HCoVs) have been evidenced to be cross-reactive to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Although a correlation exists between the immunological memory to HCoVs and coronavirus disease 2019 (COVID-19) severity, there is little experimental evidence for the effects of HCoV memory on the efficacy of COVID-19 vaccines. Here, we investigated the Ag-specific immune response to COVID-19 vaccines in the presence or absence of immunological memory against HCoV spike Ags in a mouse model. Pre-existing immunity against HCoV did not affect the COVID-19 vaccine-mediated humoral response with regard to Ag-specific total IgG and neutralizing Ab levels. The specific T cell response to the COVID-19 vaccine Ag was also unaltered, regardless of pre-exposure to HCoV spike Ags. Taken together, our data suggest that COVID-19 vaccines elicit comparable immunity regardless of immunological memory to spike of endemic HCoVs in a mouse model.

7.
Cell Death Dis ; 14(3): 228, 2023 03 30.
Artigo em Inglês | MEDLINE | ID: mdl-36990977

RESUMO

Influenza virus is one of the most challenging viruses threating human health. Since infection with influenza virus triggers inflammatory responses and induces cell death, the molecular and cellular mechanisms by which the virus-infected cells undergo apoptotic and necrotic cell death have been widely studied. However, most of the studies have focused on the molecular events occurring in the cytosol and there is limited information on the physiological correlation between virus-induced cell death and the viral pathogenesis in vivo. In this study, we demonstrate that the influenza virus matrix 1 (M1) protein is released from virus-infected cells and triggers apoptotic cell death of lung epithelial and pulmonary immune cells, through the activation of Toll-like receptor 4 (TLR4) signaling. Treatment with M1 protein led to robust cellular inflammatory responses, such as the production of proinflammatory cytokines and cellular reactive oxygen species (ROS), and induction of cell death. When M1 protein was administered in vivo, it induced the activation of inflammatory responses and cell death in the lungs. Furthermore, the administration of M1 aggravated lung pathology and mortality of the virus-infected mice in a TLR4-dependent manner. These results demonstrate that M1 is an important pathogenic factor contributing to influenza virus pathogenicity by enhancing cell death in the lungs, thereby expanding our understanding of the molecular mechanism of influenza virus-induced cell death through the interaction with an innate immune receptor.


Assuntos
Influenza Humana , Infecções por Orthomyxoviridae , Animais , Humanos , Camundongos , Apoptose , Espécies Reativas de Oxigênio , Receptor 4 Toll-Like/genética , Virulência , Proteínas Virais/metabolismo
8.
Liver Transpl ; 29(7): 698-710, 2023 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-36825584

RESUMO

The safety of elderly living liver donors and recipient outcomes are always of concern. In the present study, the effects of age in 2 donor groups, a 60+years old group and a 50-59 years old group (referred to as the 60s and 50s donor groups, respectively), on living donor liver transplantation were compared regarding donor safety and recipient outcomes. We retrospectively identified 209 patients 50 years and above of age at 9 centers from 2005 to 2017 in Korea. The 60s donor group represented 10% (n=21) of donor patients. One case in each group was a left liver graft, respectively, and the others were right liver grafts. Postoperative complications were more common in the 60s donor group, but the proportion of Clavien-Dindo grade III in the 60s donor group did not differ from that in the 50s donor group. In-hospital mortality did not occur among donors, and donor mortality was not reported during the observation period. Postoperative total bilirubin and hospitalization in recipients of the 60s donor group were higher and longer than in recipients of the 50s donor group, respectively. Although the cumulative overall survival of the recipients in the 60s donor group was significantly lower than that of the 50s donor group, a difference was not observed in graft survival. Multivariate analysis showed that increased living liver donors age, the coexistence of HCC, and increased intraoperative blood loss during the recipient operation were important predisposing factors for patient death. Present study suggests that highly selected elderly living donors (≥60 y) can safely donate with similar recipient graft survival rates though the recipient overall patient survival is inferior compared to the 50s donor group.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Transplante de Fígado , Humanos , Idoso , Pessoa de Meia-Idade , Criança , Transplante de Fígado/efeitos adversos , Doadores Vivos , Estudos Retrospectivos , Carcinoma Hepatocelular/etiologia , Neoplasias Hepáticas/etiologia , República da Coreia/epidemiologia , Sobrevivência de Enxerto , Resultado do Tratamento
9.
Environ Pollut ; 317: 120741, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36435285

RESUMO

Atmospheric particulate matter (PM) contains a mixture of chemical and biological elements that pose threat to human health by increasing susceptibility to respiratory diseases. Although the identification of the microorganisms composing the PM has been assessed, their immunological impacts are still questionable. Here, we examined the mechanisms responsible for the pathogenicity of Pseudomonas stutzeri PM101005 (PMPS), a bacterium isolated from fine dust, in lung epithelial cells, alveolar cells, and macrophages. Relative to its comparative strain Pseudomonas stutzeri (PS), infections with PMPS induced higher production of inflammatory cytokines and chemokines, mediated by the activation of NF-κB and MAPK signaling pathways. Additionally, with three-dimensional (3D) airway spheroids which mimic the human bronchial epithelium, we confirmed that PMPS infections lead to relatively higher induction of pro-inflammatory cytokines than PM infections. Consistent results were observed in murine models as the infections with PMPS provoked greater inflammatory responses than the infections with PS. These PMPS-induced responses were mediated by the signaling pathways of the Toll-like receptors (TLRs), which regulated PMPS infection and played an important role in the expression of the antibiotic peptide ß-defensin 3 (BD3) that suppressed PMPS proliferation. Moreover, PM pretreatment enhanced inflammatory responses and tissue damage of PMPS, while reducing BD3 expression. Overall, these results indicate that PM-isolated PMPS induce TLR-mediated inflammatory responses in lung tissues, and contributes to the understanding of the etiology of PM-induced respiratory damage.


Assuntos
Material Particulado , Pseudomonas stutzeri , Camundongos , Humanos , Animais , Material Particulado/toxicidade , Material Particulado/metabolismo , Pseudomonas stutzeri/metabolismo , Pulmão/metabolismo , Citocinas/metabolismo , Transdução de Sinais
10.
Cell Mol Immunol ; 19(6): 715-725, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35459853

RESUMO

Host immune responses, such as those initiated by pattern recognition receptor (PRR) activation, are important for viral clearance and pathogenesis. However, little is known about the interactions of viral proteins with surface PRRs or, more importantly, the association of innate immune activation with viral pathogenesis. In this study, we showed that internal influenza virus proteins were released from infected cells. Among these proteins, nucleoprotein (NP) played a critical role in viral pathogenesis by stimulating neighboring cells through toll-like receptor (TLR)2, TLR4, and the NLR family pyrin domain containing 3 (NLRP3) inflammasome. Through the activation of these PRRs, NP induced the production of interleukin (IL)-1ß and IL-6, which subsequently led to the induction of trypsin. Trypsin induced by NP increased the infectivity of influenza virus, leading to increases in viral replication and pathology upon subsequent viral infection. These results reveal the role of released NP in influenza pathogenesis and highlight the importance of the interactions of internal viral proteins with PRRs in the extracellular compartment during viral pathogenesis.


Assuntos
Influenza Humana , Orthomyxoviridae , Receptor 4 Toll-Like , Humanos , Inflamassomos/metabolismo , Influenza Humana/metabolismo , Influenza Humana/virologia , Interleucina-1beta/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Nucleoproteínas , Orthomyxoviridae/metabolismo , Receptor 4 Toll-Like/metabolismo , Tripsina/metabolismo
11.
Microbes Infect ; 24(1): 104878, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34384869

RESUMO

Influenza is an acute respiratory disease and a global health problem. Although influenza vaccines are commercially available, frequent antigenic changes in hemagglutinin might render them less effective or unavailable. We previously reported that modified outer membrane vesicle (fmOMV) provided immediate and robust protective immunity against various subtypes of influenza virus. However, the effect was transient because it was innate immunity-dependent. In this study, we investigated the effects of consecutive administration of fmOMV and influenza virus on the adaptive immune response and long-term protective immunity against influenza virus. When the mice were pretreated with fmOMV and subsequently infected with influenza virus, strong influenza-specific antibody and T cell responses were induced in both systemic and lung mucosal compartments without pathogenic symptoms. Upon the secondary viral challenge at week 4, the mice given fmOMV and influenza virus exhibited almost complete protection against homologous and heterologous viral challenge. More importantly, this strong protective immunity lasted up to 18 weeks after the first infection. These results show that pretreatment with fmOMV and subsequent infection with influenza virus efficiently induces broad and long-lasting protective immunity against various virus subtypes, suggesting a novel antiviral strategy against newly-emerging viral diseases without suitable vaccines or therapeutics.


Assuntos
Vacinas contra Influenza , Influenza Humana , Infecções por Orthomyxoviridae , Orthomyxoviridae , Imunidade Adaptativa , Animais , Anticorpos Antivirais , Humanos , Camundongos , Camundongos Endogâmicos BALB C
12.
EMBO Mol Med ; 14(1): e14678, 2022 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-34842355

RESUMO

Shiga toxins (Stxs) produced by enterohemorrhagic Escherichia coli (EHEC) are the major virulence factors responsible for hemorrhagic colitis, which can lead to life-threatening systemic complications including acute renal failure (hemolytic uremic syndrome) and neuropathy. Here, we report that O-GlcNAcylation, a type of post-translational modification, was acutely increased upon induction of endoplasmic reticulum (ER) stress in host cells by Stxs. Suppression of the abnormal Stx-mediated increase in O-GlcNAcylation effectively inhibited apoptotic and inflammatory responses in Stx-susceptible cells. The protective effect of O-GlcNAc inhibition for Stx-mediated pathogenic responses was also verified using three-dimensional (3D)-cultured spheroids or organoids mimicking the human kidney. Treatment with an O-GlcNAcylation inhibitor remarkably improved the major disease symptoms and survival rate for mice intraperitoneally injected with a lethal dose of Stx. In conclusion, this study elucidates O-GlcNAcylation-dependent pathogenic mechanisms of Stxs and demonstrates that inhibition of aberrant O-GlcNAcylation is a potential approach to treat Stx-mediated diseases.


Assuntos
Infecções por Escherichia coli , Síndrome Hemolítico-Urêmica , Animais , Estresse do Retículo Endoplasmático , Síndrome Hemolítico-Urêmica/patologia , Rim/patologia , Camundongos , Toxina Shiga/metabolismo , Toxinas Shiga
13.
Immune Netw ; 21(1): e4, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33728097

RESUMO

The global outbreak of coronavirus disease 2019 (COVID-19) is still threatening human health, economy, and social life worldwide. As a counteraction for this devastating disease, a number of vaccines are being developed with unprecedented speed combined with new technologies. As COVID-19 vaccines are being developed in the absence of a licensed human coronavirus vaccine, there remain further questions regarding the long-term efficacy and safety of the vaccines, as well as immunological mechanisms in depth. This review article discusses the current status of COVID-19 vaccine development, mainly focusing on antigen design, clinical trials in later stages, and immunological considerations for further study.

14.
Immune Netw ; 20(4): e28, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32895615

RESUMO

The recent emergence of the novel coronavirus (CoV) or severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) poses a global threat to human health and economy. As of June 26, 2020, over 9.4 million cases of infection, including 482,730 deaths, had been confirmed across 216 countries. To combat a devastating virus pandemic, numerous studies on vaccine development are urgently being accelerated. In this review article, we take a brief look at the characteristics of SARS-CoV-2 in comparison to SARS and Middle East respiratory syndrome (MERS)-CoVs and discuss recent approaches to coronavirus disease-2019 (COVID-19) vaccine development.

15.
Cell Microbiol ; 22(11): e13249, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32772454

RESUMO

Shiga toxins (Stxs) produced by Stx-producing Escherichia coli are the primarily virulence factors of hemolytic uremic syndrome and central nervous system (CNS) impairment. Although the precise mechanisms of toxin dissemination remain unclear, Stxs bind to extracellular vesicles (EVs). Exosomes, a subset of EVs, may play a key role in Stx-mediated renal injury. To test this hypothesis, we isolated exosomes from monocyte-derived macrophages in the presence of Stx2a or Stx2 toxoids. Macrophage-like differentiated THP-1 cells treated with Stxs secreted Stx-associated exosomes (Stx-Exo) of 90-130 nm in diameter, which induced cytotoxicity in recipient cells in a toxin receptor globotriaosylceramide (Gb3 )-dependent manner. Stx2-Exo engulfed by Gb3 -positive cells were translocated to the endoplasmic reticulum in the human proximal tubule epithelial cell line HK-2. Stx2-Exo contained pro-inflammatory cytokine mRNAs and proteins and induced more severe inflammation than purified Stx2a accompanied by greater death of target cells such as human renal or retinal pigment epithelial cells. Blockade of exosome biogenesis using the pharmacological inhibitor GW4869 reduced Stx2-Exo-mediated human renal cell death. Stx2-Exo isolated from human primary monocyte-derived macrophages activated caspase 3/7 and resulted in significant cell death in primary human renal cortical epithelial cells. Based on these results, we speculate that Stx-containing exosomes derived from macrophages may exacerbate cytotoxicity and inflammation and trigger cell death in toxin-sensitive cells. Therapeutic interventions targeting Stx-containing exosomes may prevent or ameliorate Stx-mediated acute vascular dysfunction.


Assuntos
Exossomos/metabolismo , Macrófagos/metabolismo , Toxina Shiga II/metabolismo , Toxina Shiga II/toxicidade , Triexosilceramidas/metabolismo , Caspase 3/metabolismo , Caspase 7/metabolismo , Morte Celular , Retículo Endoplasmático/metabolismo , Estresse do Retículo Endoplasmático , Exossomos/imunologia , Exossomos/ultraestrutura , Humanos , Inflamação , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , Interleucina-8/genética , Interleucina-8/metabolismo , Leucócitos Mononucleares/imunologia , Macrófagos/imunologia , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Toxina Shiga II/farmacologia , Células THP-1
16.
Lab Anim Res ; 36: 27, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32817844

RESUMO

Genome editing has recently emerged as a powerful tool for generating mutant mice. Small deletions of nucleotides in the target genes are frequently found in CRISPR/Cas9 mediated mutant mice. However, there are very few reports analyzing the phenotypes in small deleted mutant mice generated by CRISPR/Cas9. In this study, we generated a mutant by microinjecting sgRNAs targeting the IL2 receptor γ gene and Cas9 protein, into the cytoplasm of IVF-derived NOD.CB17/Prkdcscid/JKrb (NOD/SCID) mice embryos, and further investigated whether a 2 bp deletion of the IL2 receptor γ gene affects severe deficiency of immune cells as seen in NOD/LtSz-scid IL2 receptor γ-/- (NSG) mice. Our results show that the thymus weight of mutant mice is significantly less than that of NOD/SCID mice, whereas the spleen weight was marginally less. T and B cells in the mutant mice were severely deficient, and NK cells were almost absent. In addition, tumor growth was exceedingly increased in the mutant mice transplanted with HepG2, Raji and A549 cells, but not in nude and NOD/SCID mice. These results suggest that the NOD/SCID mice with deletion of 2 bp in the IL2 receptor γ gene shows same phenotype as NSG mice. Taken together, our data indicates that small deletions by genome editing is sufficient to generate null mutant mice.

17.
Cells ; 9(1)2020 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-31936366

RESUMO

O-linked ß-N-acetylglucosamine (O-GlcNAc) modification regulates the activity of hundreds of nucleocytoplasmic proteins involved in a wide variety of cellular processes, such as gene expression, signaling, and cell growth; however, the mechanism underlying the regulation of B cell development and function by O-GlcNAcylation remains largely unknown. Here, we demonstrate that changes in cellular O-GlcNAc levels significantly affected the growth of pre-B cells, which rapidly proliferate to allow expansion of functional clones that express successfully rearranged heavy chains at the pro-B stage during early B cell development. In our study, the overall O-GlcNAc levels in these proliferative pre-B cells, which are linked to the glucose uptake rate, were highly induced when compared with those in pro-B cells. Thus, pharmacologically, genetically, or nutritionally, inhibition of O-GlcNAcylation in pre-B cells markedly downregulated c-Myc expression, resulting in cell cycle arrest via blockade of cyclin expression. Importantly, the population of B cells after the pro-B cell stage in mouse bone marrow was severely impaired by the administration of an O-GlcNAc inhibitor. These results strongly suggest that O-GlcNAcylation-dependent expression of c-Myc represents a new regulatory component of pre-B cell proliferation, as well as a potential therapeutic target for the treatment of pre-B cell-derived leukemia.


Assuntos
Acetilglucosamina/química , Proliferação de Células , Células Precursoras de Linfócitos B/citologia , Processamento de Proteína Pós-Traducional , Proteínas Proto-Oncogênicas c-myc/metabolismo , Animais , Ciclo Celular , Feminino , Glicosilação , Camundongos , Camundongos Endogâmicos BALB C , Células Precursoras de Linfócitos B/metabolismo , Proteínas Proto-Oncogênicas c-myc/genética , Transdução de Sinais
18.
Immunol Lett ; 219: 27-33, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31901375

RESUMO

Obesity has been associated with increased symptoms and mortality in influenza patients and impaired immune responses to the influenza vaccine. To date, however, there is no effective adjuvant to improve vaccine efficacy for the obese population. To address this issue, we generated a modified outer membrane vesicle with attenuated endotoxicity (fmOMV) and tested its adjuvant effect on the influenza vaccine in comparison with a squalene-based oil-in-water adjuvant (AddaVax) using a diet-induced obese (DIO) mouse model. Although coadministration of fmOMV did not affect neutralizing antibody (Ab) response, it preferentially induced IgG2c antibody response and significantly increased the vaccine-induced T cell response. More importantly, fmOMV conferred significant protection against homologous and heterologous influenza virus challenge, whereas AddaVax showed marginal protection irrespective of the strongest Ab and T cell responses in DIO mice. These results indicate that fmOMV improves the antigen-specific T cell response and the efficacy of an influenza vaccine, suggesting a potential influenza vaccine adjuvant for the obese population.


Assuntos
Adjuvantes Imunológicos , Vesículas Extracelulares/metabolismo , Imunogenicidade da Vacina , Vacinas contra Influenza/imunologia , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/prevenção & controle , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Dieta , Modelos Animais de Doenças , Imunidade Celular , Vírus da Influenza A/imunologia , Masculino , Camundongos , Camundongos Obesos , Testes de Neutralização , Obesidade , Infecções por Orthomyxoviridae/metabolismo , Infecções por Orthomyxoviridae/mortalidade
19.
J Innate Immun ; 11(4): 316-329, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30844806

RESUMO

Influenza A virus (IAV) poses a constant worldwide threat to human health. Although conventional vaccines are available, their protective efficacy is type or strain specific, and their production is time-consuming. For the control of an influenza pandemic in particular, agents that are immediately effective against a wide range of virus variants should be developed. Although pretreatment of various Toll-like receptor (TLR) ligands have already been reported to be effective in the defense against subsequent IAV infection, the efficacy was limited to specific subtypes, and safety concerns were also raised. In this study, we investigated the protective effect of an attenuated bacterial outer membrane vesicle -harboring modified lipid A moiety of lipopolysaccharide (fmOMV) against IAV infection and the underlying mechanisms. Administration of fmOMV conferred significant protection against a lethal dose of pandemic H1N1, PR8, H5N2, and highly pathogenic H5N1 viruses; this broad antiviral activity was dependent on macrophages but independent of neutrophils. fmOMV induced recruitment and activation of macrophages and elicited type I IFNs. Intriguingly, fmOMV showed a more significant protective effect than other TLR ligands tested in previous reports, without exhibiting any adverse effect. These results show the potential of fmOMV as a prophylactic agent for the defense against influenza virus infection.


Assuntos
Membrana Externa Bacteriana/imunologia , Vírus da Influenza A/fisiologia , Vacinas contra Influenza/imunologia , Influenza Humana/imunologia , Lipídeo A/imunologia , Macrófagos/imunologia , Infecções por Orthomyxoviridae/imunologia , Vesículas Secretórias/imunologia , Animais , Escherichia coli/genética , Feminino , Humanos , Interferon Tipo I/metabolismo , Ligantes , Lipídeo A/genética , Camundongos , Camundongos Endogâmicos C57BL , Transdução de Sinais , Receptores Toll-Like/agonistas
20.
Nanomedicine ; 17: 223-235, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30695729

RESUMO

Hemagglutinin (HA) displayed on a ferritin nano-cage has been shown to be effective in generating a potent immune response against a broad range of influenza infections. Here, we showed that conjugation of flagellin together with HA to the exterior surface of the ferritin cage greatly enhanced not only the humoral immune response in mice but also antigen-specific T cell responses that include Th1 cytokine secretion. The effect of flagellin remained essentially unchanged when the molar ratio of flagellin to HA was reduced from 1:1 to 1:3. Injection of the ferritin-HA-flagellin cage provided protection against lethal virus challenge in mice. We used a small immunoglobulin fragment VL12.3 as a convenient method for attaching HA and flagellin to the ferritin cage. This attachment method can be used for rapid screening of a variety of protein cages and nano-assemblies to identify the most suitable carrier and adjuvant proteins for the target antigen.


Assuntos
Adjuvantes Imunológicos/química , Ferritinas/química , Flagelina/química , Glicoproteínas de Hemaglutininação de Vírus da Influenza/química , Vírus da Influenza A/química , Salmonella typhimurium/química , Adjuvantes Imunológicos/farmacologia , Animais , Linhagem Celular , Feminino , Ferritinas/farmacologia , Flagelina/farmacologia , Glicoproteínas de Hemaglutininação de Vírus da Influenza/farmacologia , Humanos , Imunidade Celular/efeitos dos fármacos , Imunidade Humoral/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Nanoestruturas/química
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