PARP7 is a member of the ADP-ribosyltransferase diphtheria toxin-like (ARTD) family and acts as a repressor of type I interferon (IFN) signaling. PARP7 inhibition causes tumor regression by enhancing antitumor immunity, which is dependent on the stimulator of interferon genes (STING) pathway, TANK-binding kinase 1 (TBK1) activity, and cytotoxic CD8 T cells. To better understand PARP7's role in cancer, we generated and characterized PARP7 knockout (Parp7) EO771 mouse mammary cancer cells in vitro and in a preclinical syngeneic tumor model using catalytic mutant mice.
View Article and Find Full Text PDFAmong cancer immunotherapy, which has received great attention in recent years, cancer vaccines can potentially prevent recurrent tumors by using the exquisite power and specificity of the immune system. Specifically, whole tumor cell vaccines (WTCVs) based on surgically resected tumors have been considered to elicit robust anti-tumor immune responses by exposing various tumor-associated antigens to host immunity. However, most tumors have little immunogenicity because of immunoediting by continuous interactions with host immunity; thus, preparing WTCVs based on patient-derived non-modified tumors cannot prevent tumor onset.
View Article and Find Full Text PDFSevere acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is the causative virus of pandemic acute respiratory disease called coronavirus disease 2019 (COVID-19). Most of the infected individuals have asymptomatic or mild symptoms, but some patients show severe and critical systemic inflammation including tissue damage and multi-organ failures. Immune responses to the pathogen determine clinical course.
View Article and Find Full Text PDFIntracellular and cell surface pattern-recognition receptors (PRRs) are an essential part of innate immune recognition and host defense. Here, we have compared the innate immune responses between humans and bats to identify a novel membrane-associated protein, Rnd1, which defends against viral and bacterial infection in an interferon-independent manner. Rnd1 belongs to the Rho GTPase family, but unlike other small GTPase members, it is constitutively active.
View Article and Find Full Text PDFAlthough mindfulness-based stress reduction (MBSR) improves cognitive function, the mechanism is not clear. In this study, people aged 65 years and older were recruited from elderly communities in Chitose City, Japan, and assigned to a non-MBSR group or a MBSR group. Before and after the intervention, the Japanese version of the Montreal Cognitive Assessment (MoCA-J) was administered, and blood samples were collected.
View Article and Find Full Text PDFThe interaction of viral nucleic acid with protein factors is a crucial process for initiating viral polymerase-mediated viral genome replication while activating pattern recognition receptor (PRR)-mediated innate immune responses. It has previously been reported that a hydrolysate of Ge-132, 3-(trihydroxygermyl) propanoic acid (THGP), shows a modulatory effect on microbial infections, inflammation, and immune responses. However, the detailed mechanism by which THGP can modify these processes during viral infections remained unknown.
View Article and Find Full Text PDFType-I interferons (IFN-I) are the innate immune system's principal defense against viral infections. Human immunodeficiency virus-1 (HIV-1) has evolved several ways to suppress or evade the host's innate immunity in order to survive and replicate to sustain infection. Suppression of IFN-I is one among the multiple escape strategies used by HIV-1 to prevent its clearance.
View Article and Find Full Text PDFEfficient immune responses against viral infection are determined by sufficient activation of nucleic acid sensor-mediated innate immunity. Coronavirus disease 2019, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), remains an ongoing global pandemic. It is an urgent challenge to clarify the innate recognition mechanism to control this virus.
View Article and Find Full Text PDFStimulator of interferon genes (STING) plays important roles in the DNA-mediated innate immune responses. However, the regulatory mechanism of STING in terms of stabilization is not fully understood. Here, we identified the chaperone protein Hsp90s as novel STING interacting proteins.
View Article and Find Full Text PDFPrecise regulation of innate immunity is crucial for development of appropriate host immunity against microbial infections and maintenance of immune homeostasis. MicroRNAs are small non-coding RNAs, post-transcriptional regulator of multiple genes, and act as a rheostat for protein expression. Here, we identified microRNA-30e-5p induced by hepatitis B virus and other viruses that act as a master regulator for innate immunity.
View Article and Find Full Text PDFRecently, aging is becoming an important social problem in many developed countries including Japan. It is socially and universally important to unveil the impact of aging and extend healthy life expectancy. Here we show our recent finding that dedicator of cytokinesis 11 (DOCK11, also known as Zizimin2) may be involved in immunosenescence of B cells.
View Article and Find Full Text PDFPurpose: The aim of this study was to test the antiviral effectivity of potassium peroxymonosulfate (RUBYSTA, KYORIN) against five epidemic keratoconjunctivitis-related types of in vitro.
Methods: Five types of (8, 37, 53, 54 and 56) were incubated with 1% potassium peroxymonosulfate, 0.1% sodium hypochlorite (NaClO) or alcohol-based disinfectant for 30 s or 1 min.
Type I and type III interferons are important anti-viral cytokines that are massively induced during viral infection. This dynamic process is regulated by many executors and regulators for efficient eradication of invading viruses and protection from harmful, excessive responses. An array of innate sensors recognizes virus-derived nucleic acids to activate their downstream signaling to evoke cytokine responses including interferons.
View Article and Find Full Text PDFBackground: Conventional treatments of chronic hepatitis B virus (HBV) infection rarely achieve a decline of serum hepatitis B surface antigen (HBsAg) levels and eradication of the virus.
Aim: To elucidate the antiviral mechanisms of a human microRNA, miR-302c-3p, against HBV replication.
Methods: The antiviral effect of miR-302c-3p was evaluated in vitro and in vivo by transfecting the miR-302c-3p mimic into HBV-infected HepG2-hNTCP-C4 cells and HBV transgenic mice respectively.
Biochem Biophys Res Commun
April 2019
Innate immunity is a system that recognizes primarily and excludes pathogenic microorganism. MAVS/IPS-1/Cardif/Visa functions as an adapter protein for RIG-I like receptors (RLRs) and plays a key role in the production of antiviral proteins, interferons (IFNs), for RNA viruses. However, the activation mechanism is not fully understood.
View Article and Find Full Text PDFMicroRNAs (miRNAs) are small noncoding RNAs that are crucial posttranscriptional regulators for host mRNAs. Recent studies indicate that miRNAs may modulate host response during RNA virus infection. However, the role of miRNAs in immune response against H5N1 infection is not clearly understood.
View Article and Find Full Text PDFZizimin2 (Ziz2), also known as dedicator of cytokinesis 11 (DOCK11), is a guanine nucleotide exchange factor that is predominantly expressed in lymphoid tissues. Recent findings demonstrated that Ziz2 is involved in the development of B cells, including germinal centre B cells and marginal zone B cells. However, limited information is currently available on the roles of Ziz2 in B-1 cells, a B-cell subset that resides in body cavities and contributes to protection against foreign pathogens in a T-cell-independent manner.
View Article and Find Full Text PDFCancer is a multifactorial disease and virus-mediated carcinogenesis is one of the crucial factors, which is poorly understood. Human cytomegalovirus (HCMV) is a herpesvirus and its components have been evidenced to be associated with cancer of different tissue origin. However, its role in cancer remains unknown.
View Article and Find Full Text PDFBlack yeast, Aureobasidium pullulans is extracellularly produced β-(1,3), (1,6)-D-glucan (β-glucan) under certain conditions. In this study, using Glycine max cv. Kurosengoku (Kurosengoku soybeans), the production of β-glucan through fermentation of A.
View Article and Find Full Text PDFThe host factor and interferon (IFN)-stimulated gene (ISG) product, zinc-finger antiviral protein (ZAP), inhibits a number of diverse viruses by usurping and intersecting with multiple cellular pathways. To elucidate its antiviral mechanism, we perform a loss-of-function genome-wide RNAi screen to identify cellular cofactors required for ZAP antiviral activity against the prototype alphavirus, Sindbis virus (SINV). In order to exclude off-target effects, we carry out stringent confirmatory assays to verify the top hits.
View Article and Find Full Text PDFActivation of the aryl hydrocarbon receptor (AHR) by endogenous ligands has been implicated in a variety of physiological processes such as cell cycle regulation, cell differentiation and immune responses. It is reported that tryptophan metabolites, such as kynurenine (Kyn) and 6-formylindolo(3,2-b)carbazole (FICZ), are endogenous ligands for AHR ( Stockinger , 2014 ). This protocol is designed for treatment with Kyn or FICZ in mouse embryonic fibroblasts (MEFs) or primary peripheral monocytes.
View Article and Find Full Text PDFThe aryl hydrocarbon receptor (AHR) is known as a sensor for dioxins that mediates their toxicity, and also has important biophysiological roles such as circadian rhythms, cell differentiation and immune responses. 6-formylindolo(3,2-b)carbazole (FICZ), which is derived through the metabolism of L-tryptophan by ultraviolet B irradiation, is one of putative physiological ligands for AHR ( Smirnova , 2016 ). It has recently been shown that endogenously-activated AHR signaling modulates innate immune response during viral infection ( Yamada , 2016 ).
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