Biology subjects

Koyanagi, Y.

Publications and source records attributed to Koyanagi, Y..

5 recordsLinked to original sources

bioRxiv2022

Single-cell transcriptome analysis illuminating the characteristics of species-specific innate immune responses against viral infections

Bats harbor various viruses without severe symptoms and act as their natural reservoirs. The tolerance of bats against viral infections is assumed to originate from the uniqueness of their immune system. However, how immune responses vary between primates and bats remains unclear. Here, we characterized differences in the immune responses by peripheral blood mononuclear cells to various pathogenic stimuli between primates (humans, chimpanzees, and macaques) and bats (Egyptian fruit bats) using single-cell RNA sequencing. We show that the induction patterns of key cytosolic DNA/RNA sensors and antiviral genes differed between primates and bats. A novel subset of monocytes induced by pathogenic stimuli specifically in bats was identified. Furthermore, bats robustly respond to DNA virus infection even though major DNA sensors are dampened in bats. Overall, our data suggest that immune responses are substantially different between primates and bats, presumably underlying the difference in viral pathogenicity among the mammalian species tested.

microbiology↗

bioRxiv2020

SARS-CoV-2 ORF3b is a potent interferon antagonist whose activity is further increased by a naturally occurring elongation variant

One of the features distinguishing SARS-CoV-2 from its more pathogenic counterpart SARS-CoV is the presence of premature stop codons in its ORF3b gene. Here, we show that SARS-CoV-2 ORF3b is a potent interferon antagonist, suppressing the induction of type I interferon more efficiently than its SARS-CoV ortholog. Phylogenetic analyses and functional assays revealed that SARS-CoV-2-related viruses from bats and pangolins also encode truncated ORF3b gene products with strong anti-interferon activity. Furthermore, analyses of more than 15,000 SARS-CoV-2 sequences identified a natural variant, in which a longer ORF3b reading frame was reconstituted. This variant was isolated from two patients with severe disease and further increased the ability of ORF3b to suppress interferon induction. Thus, our findings not only help to explain the poor interferon response in COVID-19 patients, but also describe a possibility of the emergence of natural SARS-CoV-2 quasispecies with extended ORF3b that may exacerbate COVID-19 symptoms. HighlightsO_LIORF3b of SARS-CoV-2 and related bat and pangolin viruses is a potent IFN antagonist C_LIO_LISARS-CoV-2 ORF3b suppresses IFN induction more efficiently than SARS-CoV ortholog C_LIO_LIThe anti-IFN activity of ORF3b depends on the length of its C-terminus C_LIO_LIAn ORF3b with increased IFN antagonism was isolated from two severe COVID-19 cases C_LI

microbiology↗

bioRxiv2020

Endogenous retroviruses drive KRAB zinc-finger family protein expression for tumor suppression

Numerous genes are aberrantly expressed in tumors, but its cause remains unclear. Human endogenous retroviruses (HERVs) are repetitive elements in the genome and have a potential to work as enhancers modulating adjacent genes. Since numerous HERVs are activated epigenetically in tumors, their activation could alter gene expression globally in tumors and change the tumor characteristics. Here, we show the HERV activation in tumors is associated with the upregulation of hundreds of transcriptional suppressors, Kruppel-associated box domain-containing zinc-finger family proteins (KZFPs). KZFP genes are preferentially encoded nearby the activated HERVs in tumors and transcriptionally regulated by the adjacent HERVs. Increased HERV and KZFP expression in tumors was associated with better disease conditions. Many KZFPs could suppress the progressive characteristics of cancer cells by downregulating genes related to the cell cycle and cell-matrix adhesion. Our data suggest that HERV activation in tumors drives the concerted expression of KZFP genes for tumor suppression.

cancer biology↗

bioRxiv2019

Systematic detection of Mendelian and non-Mendelian variants associated with retinitis pigmentosa by genome-wide association study

To uncover genetic basis of autosomal recessive retinitis pigmentosa (ARRP), we applied 2-step genome-wide association study (GWAS) in 640 Japanese patients prescreened with targeted re-sequencing. Meta-GWAS identified three independent peaks at P < 5.0x10-8, all within the major ARRP gene EYS. Two were each tagged by a low frequency variant (allele frequency < 0.05); a known founder Mendelian mutation (c.4957dupA, p.S1653Kfs*2) and a presumably hypomorphic non-synonymous variant (c.2528G>A, p.G843E). c.2528G>A newly solved 7.0% of Japanese ARRP cases, improving genetic diagnosis by 26.8% and simultaneously serving as a new attractive target for genome editing gene therapy. The third peak was tagged by an intronic common variant, representing a novel disease-susceptibility signal. GWAS successfully unraveled genetic causes of a rare "monogenic" disorder for the first time, which provided unexpected insights into significant contribution of non-Mendelian genetic factors and identified a novel high frequency variant directly linked to development of local genome therapeutics.

genetics↗

bioRxiv2018

Gorilla APOBEC3 restricts SIVcpz and influences lentiviral evolution in great ape cross-species transmissions

Restriction factors including APOBEC3 family proteins have the potential prevent cross-species lentivirus transmissions. Such events as well as ensuing pathogenesis require the viral Vif protein to overcome/neutralize/degrade the APOBEC3 enzymes of the new host species. Previous investigations have focused on the molecular interaction between human APOBEC3s and HIV-1 Vif. However, the evolutionary interplay between lentiviruses and great ape (including human, chimpanzee and gorilla) APOBEC3s has not been fully investigated. Here we demonstrate that gorilla APOBEC3G plays a pivotal role in restricting lentiviral transmission from chimpanzee to gorilla. We also reveal that a sole amino acid substitution in Vif is sufficient to overcome the gorilla APOBEC3G-mediated species barrier. Moreover, the antiviral effects of gorilla APOBEC3D and APOBEC3F are considerably weaker than those of human and chimpanzee counterparts, which can result in the skewed evolution of great ape lentiviruses leading to HIV-1.\n\nHighlightsO_LISIVcpz requires M16E mutation in Vif to counteract gorilla A3G\nC_LIO_LIAcidic residue at position 16 of Vif is crucial to counteract gorilla A3G\nC_LIO_LIGorilla A3D and A3F poorly suppress lentiviral infectivity\nC_LIO_LISIVgor and related HIV-1s counteract human A3D and A3F independently of DRMR motif\nC_LI

microbiology↗