|
所属 |
医学部 医学科 感染症学講座免疫学分野 |
|
職名 |
助教 |
|
外部リンク |
|
論文 【 表示 ／ 非表示 】
-
Mitoma S., Carr B.V., Harvey Y., Moffat K., Sekiguchi S., Charleston B., Norimine J., Seago J.
Immunology 164 ( 2 ) 266 - 278 2021年10月
担当区分：筆頭著者 記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Immunology
Foot-and-mouth disease (FMD) is a highly contagious, economically devastating disease of cloven-hooved animals. The development of long-lasting effective FMD vaccines would greatly benefit the global FMD control programme. Deep analysis of adaptive immunity in cattle vaccinated against FMD is technically challenging due to the lack of species-specific tools. In this study, we aimed to identify CD4+ T-cell epitopes in the FMD virus (FMDV) capsid and to phenotype the CD4+ T cells that recognize them using bovine major histocompatibility complex (BoLA) class II tetramer. A BoLA class II tetramer based on the DRA/DRB3*020:02 allele and FMDV antigen-stimulated PBMCs from bovine vaccinates were used to successfully identify four epitopes in the FMDV capsid, three of which have not been previously reported; two epitopes were identified in the structural protein VP1, one in VP3 and one in VP4. Specificity of the three novel epitopes was confirmed by proliferation assay. All epitope-expanded T-cell populations produced IFN-γ in vitro, indicating a long-lasting Th1 cell phenotype after FMD vaccination. VP3-specific CD4+ T cells exhibited the highest frequency amongst the identified epitopes, comprising >0·004% of the CD4+ T-cell population. CD45RO+CCR7+ defined central memory CD4+ T-cell subpopulations were present in higher frequency in FMDV-specific CD4+ T-cell populations from FMD-vaccinated cattle ex vivo. This indicates an important role in maintaining cell adaptive immunity after FMD vaccination. Notably, FMDV epitope-loaded tetramers detected the presence of FMDV-specific CD4+ T cells in bovine PBMC more than four years after vaccination. This work contributes to our understanding of vaccine efficacy.
DOI： 10.1111/imm.13367
-
Fukaya T., Uto T., Mitoma S., Takagi H., Nishikawa Y., Tominaga M., Choijookhuu N., Hishikawa Y., Sato K.
Cell Reports 42 ( 5 ) 2023年5月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Cell Reports
While dysbiosis in the gut is implicated in the impaired induction of oral tolerance generated in mesenteric lymph nodes (MesLNs), how dysbiosis affects this process remains unclear. Here, we describe that antibiotic-driven gut dysbiosis causes the dysfunction of CD11c+CD103+ conventional dendritic cells (cDCs) in MesLNs, preventing the establishment of oral tolerance. Deficiency of CD11c+CD103+ cDCs abrogates the generation of regulatory T cells in MesLNs to establish oral tolerance. Antibiotic treatment triggers the intestinal dysbiosis linked to the impaired generation of colony-stimulating factor 2 (Csf2)-producing group 3 innate lymphoid cells (ILC3s) for regulating the tolerogenesis of CD11c+CD103+ cDCs and the reduced expression of tumor necrosis factor (TNF)-like ligand 1A (TL1A) on CD11c+CD103+ cDCs for generating Csf2-producing ILC3s. Thus, antibiotic-driven intestinal dysbiosis leads to the breakdown of crosstalk between CD11c+CD103+ cDCs and ILC3s for maintaining the tolerogenesis of CD11c+CD103+ cDCs in MesLNs, responsible for the failed establishment of oral tolerance.
-
Wu X., Notsu K., Matsuura Y., Mitoma S., El Daous H., Norimine J., Sekiguchi S.
Journal of Virological Methods 315 2023年5月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Journal of Virological Methods
Bovine leukemia virus (BLV) is the causative agent of a B-cell tumor called enzootic bovine leukosis. Preventing BLV spreading is required to reduce economic loss related to BLV infection of livestock. To quantify proviral load (PVL) more easily and rapidly, we developed a quantification system of PVL using droplet digital PCR (ddPCR). This method uses a multiplex TaqMan assay of the BLV provirus and housekeeping gene RPP30 for the quantification of BLV in BLV-infected cells. Furthermore, we combined ddPCR with DNA purification-free sample preparation (unpurified genomic DNA). The percentage of BLV-infected cells based on unpurified genomic DNA was highly correlated with that based on purified genomic DNA (correlation coefficient: 0.906). Thus, this new technique is a suitable method to quantify PVL of BLV-infected cattle in a large sample number.
-
Identifying Pathogen and Allele Type Simultaneously in a Single Well Using Droplet Digital PCR. 査読あり 国際誌
Kosuke Notsu, Hala El Daous, Shuya Mitoma, Xinyue Wu, Junzo Norimine, Satoshi Sekiguchi
mSphere e0049322 2023年1月
記述言語：英語 掲載種別：研究論文（学術雑誌）
In the transmission control of chronic and untreatable livestock diseases such as bovine leukemia virus (BLV) infection, the removal of viral superspreaders is a fundamental approach. On the other hand, selective breeding of cattle with BLV-resistant capacity is also critical for reducing the viral damage to productivity by keeping infected cattle. To provide a way of measuring BLV proviral load (PVL) and identifying susceptible/resistant cattle simply and rapidly, we developed a fourplex droplet digital PCR method targeting the BLV pol gene, BLV-susceptible bovine major histocompatibility complex (BoLA)-DRB3*016:01 allele, resistant DRB3*009:02 allele, and housekeeping RPP30 gene (IPATS-BLV). IPATS-BLV successfully measured the percentage of BLV-infected cells and determined allele types precisely. Furthermore, it discriminated homozygous from heterozygous carriers. Using this method to determine the impact of carrying these alleles on the BLV PVL, we found DRB3*009:02-carrying cattle could suppress the PVL to a low or undetectable level, even with the presence of a susceptible heterozygous allele. Although the population of DRB3*016:01-carrying cattle showed significantly higher PVLs compared with cattle carrying other alleles, their individual PVLs were highly variable. Because of the simplicity and speed of this single-well assay, our method has the potential of being a suitable platform for the combined diagnosis of pathogen level and host biomarkers in other infectious diseases satisfying the two following characteristics of disease outcomes: (i) pathogen level acts as a critical maker of disease progression; and (ii) impactful disease-related host genetic biomarkers are already identified. IMPORTANCE While pathogen-level quantification is an important diagnostic of disease severity and transmissibility, disease-related host biomarkers are also useful in predicting outcomes in infectious diseases. In this study, we demonstrate that combined proviral load (PVL) and host biomarker diagnostics can be used to detect bovine leukemia virus (BLV) infection, which has a negative economic impact on the cattle industry. We developed a fourplex droplet digital PCR assay for PVL of BLV and susceptible and resistant host genes named IPATS-BLV. IPATS-BLV has inherent merits in measuring PVL and identifying susceptible and resistant cattle with superior simplicity and speed because of a single-well assay. Our new laboratory technique contributes to strengthening risk-based herd management used to control within-herd BLV transmission. Furthermore, this assay design potentially improves the diagnostics of other infectious diseases by combining the pathogen level and disease-related host genetic biomarker to predict disease outcomes.
-
Virological characteristics of the SARS-CoV-2 Omicron BA.2 subvariants, including BA.4 and BA.5 査読あり 国際誌
Kimura I., Yamasoba D., Tamura T., Nao N., Suzuki T., Oda Y., Mitoma S., Ito J., Nasser H., Zahradnik J., Uriu K., Fujita S., Kosugi Y., Wang L., Tsuda M., Kishimoto M., Ito H., Suzuki R., Shimizu R., Begum M.M., Yoshimatsu K., Kimura K.T., Sasaki J., Sasaki-Tabata K., Yamamoto Y., Nagamoto T., Kanamune J., Kobiyama K., Asakura H., Nagashima M., Sadamasu K., Yoshimura K., Shirakawa K., Takaori-Kondo A., Kuramochi J., Schreiber G., Ishii K.J., Hashiguchi T., Ikeda T., Saito A., Fukuhara T., Tanaka S., Matsuno K., Sato K.
Cell 185 ( 21 ) 3992 - 4007 2022年10月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Cell
After the global spread of the SARS-CoV-2 Omicron BA.2, some BA.2 subvariants, including BA.2.9.1, BA.2.11, BA.2.12.1, BA.4, and BA.5, emerged in multiple countries. Our statistical analysis showed that the effective reproduction numbers of these BA.2 subvariants are greater than that of the original BA.2. Neutralization experiments revealed that the immunity induced by BA.1/2 infections is less effective against BA.4/5. Cell culture experiments showed that BA.2.12.1 and BA.4/5 replicate more efficiently in human alveolar epithelial cells than BA.2, and particularly, BA.4/5 is more fusogenic than BA.2. We further provided the structure of the BA.4/5 spike receptor-binding domain that binds to human ACE2 and considered how the substitutions in the BA.4/5 spike play roles in ACE2 binding and immune evasion. Moreover, experiments using hamsters suggested that BA.4/5 is more pathogenic than BA.2. Our multiscale investigations suggest that the risk of BA.2 subvariants, particularly BA.4/5, to global health is greater than that of original BA.2.
MISC 【 表示 ／ 非表示 】
-
決定論的手法を用いた肉用牛の外部導入における牛伝染性リンパ腫ウイルス感染のリスク評価
藤原未歩, 牛谷雄一, 野津昂亮, EL-DAOUS Hala, 芹田光玲, 三苫修也, 乗峰潤三, 乗峰潤三, 関口敏, 関口敏
獣医疫学雑誌 25 ( 1 ) 2021年
掲載種別：速報，短報，研究ノート等（学術雑誌）
科研費（文科省・学振・厚労省）獲得実績 【 表示 ／ 非表示 】
-
牛伝染性リンパ腫ウイルス感染症に対するNK細胞選択的活性による防御免疫効果
研究課題/領域番号：22K15013 2022年04月 - 2025年03月
日本学術振興会 科学研究費助成事業 若手研究 若手研究
三苫 修也
担当区分：研究代表者