Biology subjects

Kotani, A.

Publications and source records attributed to Kotani, A..

6 recordsLinked to original sources

bioRxiv2025

Sensitive colorimetric ELISA measuring salivary SBP-specific secretory IgA, its application to pollinosis SLIT

BackgroundSublingual immunotherapy is safe and one of the most effective etiological treatments for pollinosis. Salivary allergen-specific secretory immunoglobulin A (SIgA) is a useful marker to objectively evaluate treatment effectiveness. However, saliva samples usually exhibit high background noise because of nonspecific binding in enzyme-linked immunosorbent assays (ELISAs). ObjectiveWe aimed to establish an amplified ELISA to measure allergen-specific salivary SIgA levels to assess the efficacy of sublingual immunotherapy (SLIT). MethodsBiotinyl tyramide (BT-Tyr) was used to amplify the signal in a colorimetric ELISA. The allergen sugi basic protein (SBP) was biotinylated and used as a reporter to obtain sensitive and specific results with low background. This ELISA was used to measure anti-SBP SIgA levels in saliva samples from SLIT-treated patients with Japanese cedar pollinosis. ResultsThe ELISA was highly sensitive and achieved more than 200-fold signal amplification compared to non-amplified conditions. It was also specific for antigens without background noise. The levels of SBP-specific SIgA in saliva increased in patients 3 months after SLIT initiation. ConclusionWe established a sensitive colorimetric ELISA to measure SBP-specific SIgA in saliva using BT-Tyr-based amplification and biotinylated antigen as a reporter. We used this sensitive ELISA to monitor the levels of SBP-specific SIgA in saliva samples from patients with pollinosis receiving SLIT. Increased salivary SBP-specific SigA levels were observed in these patients.

immunology↗

bioRxiv2024

Secreted phospholipase PLA2G12A-driven lysophospholipid signaling via lipolytic modification of extracellular vesicles facilitates pathogenic Th17 differentiation

Lipogenesis-driven metabolic flux is crucial for differentiation of pathogenic Th17 cells. Although our previous CRISPR-based screening identified PLA2G12A as a key player in this process, it has remained obscure how this secreted phospholipase A2 isoform controls Th17 differentiation. Here we show that global, T cell-specific, or fibroblast-specific deletion of PLA2G12A prevents Th17 differentiation and associated diseases including psoriasis and arthritis. PLA2G12A acts on Th17-derived extracellular vesicles (EVs) to produce lysophospholipids including the ROR{gamma}t activator 1-oleoyl-lysophosphatidylethanolamine. These lysophospholipids are further converted by autotaxin to lysophosphatidic acid (LPA), which assists Th17 differentiation mainly via LPA2 receptor. Moreover, PLA2G12A promotes the secretion and uptake of EVs by Th17 cells and alters their cargo contents. Defective Th17 differentiation by PLA2G12A deficiency is rescued by supplementation with PLA2G12A-modified EVs. Importantly, a PLA2G12A-blocking antibody prevents Th17 differentiation and ameliorates psoriasis and arthritis models. Thus, targeting the PLA2G12A-EV-lysophospholipid axis may be useful for treatment of Th17-related diseases.

immunology↗

bioRxiv2024

A single microRNA miR-195 rescues the arrested B cell development induced by EBF1 deficiency

Accumulated studies have reported that hematopoietic differentiation was primarily regulated by transcription factors. Early B cell factor 1 (EBF1) is an essential transcription factor for B lymphopoiesis. Contrary to the canonical notion, we found that a single miRNA, miRNA-195 (miR-195) transduction let EBF1 deficient hematopoietic progenitor cells (HPCs) express CD19, carry out V(D)J recombination and class switch recombination, which implied that B cell matured without EBF1. A part of the mechanism was caused by FOXO1 accumulation via inhibition of FOXO1 phosphorylation pathways in which targets of miR-195 are enriched. These results suggested that some miRNA transductions could function as alternatives to transcription factors.

immunology↗

bioRxiv2023

Mechanism Underlying the Immune Responses of a Sublingual Vaccine for SARS-CoV-2 with RBD Antigen and Adjuvant, Poly(I:C) or AddaS03, in Non-human Primates

A sublingual vaccine formulated with recombinant SARS-CoV-2 spike protein receptor binding domain (RBD) antigen and Poly(I:C)) adjuvant was assessed for its safety in non-human primates. This Poly(I:C)-adjuvanted sublingual vaccine was safe compared to the AddaS03-adjuvanted vaccine in blood tests and plasma CRP. The safety of the vaccine was also confirmed through quantitative reverse transcription PCR of six genes and ELISA of four cytokines associated with inflammation and related reactions. The Poly(I:C)- or AddaS03-adjuvanted sublingual vaccine produced RBD-specific IgA antibodies in nasal washings, saliva, and plasma. SARS-CoV-2 neutralizing antibodies were detected in plasma, suggesting that adjuvanted-sublingual vaccines protect against SARS-CoV-2 infection. "Yin and Yang"-like unique transcriptional regulation was observed through DNA microarray analyses of white blood cell RNAs from both vaccines, suppressing and enhancing immune responses and up- or downregulating genes associated with these immune responses. Poly(I:C) adjuvanted sublingual vaccination induced atypical up- or downregulation of genes related to immune suppression or tolerance; Treg differentiation; and T-cell exhaustion. Therefore, Poly(I:C) adjuvant is safe and favorable for sublingual vaccination and can induce a balanced "Yin/Yang" -like effect on immune responses.

immunology↗

bioRxiv2020

Expression of ERV3-1 in Leukocytes of Acute Myelogenous Leukemia Patients

Acute myelogenous leukemia (AML) is one of the major hematological malignancies. In the human genome, several have been found to originate from retroviruses, and some of which are involved in progression of various cancers. Hence, to investigate whether retroviral-like genes are associated with the development of AML, we conducted a transcriptome sequencing analysis of 12 retroviral-like genes of 150 AML patients using The Cancer Genome Atlas database. We found high expression of ERV3-1, an envelope gene of endogenous retrovirus group 3 member 1. In particular, blood and bone marrow cells of the myeloid lineage in AML patients, exhibited higher expression of ERV3-1 than those of the monocytic AML lineage. We also examined the protein expression of ERV3-1 by immunohistochemical analysis and found expression of ERV3-1 protein in 7 out of 12 AML patients, with a particular concentration observed at the membrane of some leukemic cells. Transcriptome analysis further suggested that upregulated ERV3-1 expression may be associated with chromosome 8 trisomy as anomaly was found to be more common among the high expression group compared to the low expression group. However, this finding was not corroborated by the immunohistochemical data. This discrepancy may have been caused, in part, by the small number of samples analyzed in this study. Although the precise associated molecular mechanisms remain unclear, our results suggest that ERV3-1 may be involved in AML development. HighlightsO_LIExpression of 12 retroviral-like genes in the human genome were analyzed using transcriptome data of 150 acute myelogenous leukemia (AML) patients. C_LIO_LIERV3-1, an envelope gene of endogenous retrovirus group 3 member 1, was found to uniquely show high expression level. C_LIO_LIMorphologic characteristics and chromosomal abnormalities are found to be related with the expression of ERV3-1. C_LI

molecular biology↗

bioRxiv2018

Identification of PTBP1 responsible for caspase dependent YRNA cleavage

Some RNAs such as 28S rRNA, U1 snRNA, and Y RNAs are known to be cleaved during apoptosis. As the underlying mechanism is yet unclear, the functions and biological significance of RNA degradation in apoptosis remain elusive. We previously identified novel, functional small RNAs named AGO-taxis small RNA (ASR) that are specifically bound to AGO1. Here, we investigated ASR biogenesis, which appears to be non-canonical. Y RNAs, non-coding RNAs degraded during apoptosis, were identified as the precursors of several ASRs. Cell-free analysis combined with fractionation methods revealed that the apoptosis-specific biogenesis of ASRs or Y RNA degradation was induced by PTBP1--an endoribonuclease inhibitor of Y RNAs. PTBP1, a splicing factor, was truncated by caspase 3, which subsequently activated endoribonuclease to induce biogenesis of ASRs and Y RNA cleavage.

molecular biology↗