44 research outputs found

    Identification of novel biomarker as citrullinated inter-alpha-trypsin inhibitor heavy chain 4, specifically increased in sera with experimental and rheumatoid arthritis

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    BackgroundAnticitrullinated protein antibodies (ACPA) and citrullinated proteins play key roles in the pathogenesis of rheumatoid arthritis (RA). Many candidate citrullinated antigens have been identified in joints, but citrullinated proteins in sera are mostly uncertain in patients with RA. We explored the expression of citrullinated proteins in joints and sera of experimental arthritis, and we further investigated their specific expression correlated with the disease activity in patients with RA.MethodsCitrullinated protein expression in tissues was examined by IHC in peptide glucose-6-phosphate isomerase-induced arthritis (pGIA). Serum citrullinated proteins from pGIA were examined by Western blotting, and the sequence was identified by MS. With the same methods, serum citrullinated proteins were analyzed in patients with RA, primary Sjögren’s syndrome, systemic lupus erythematosus, and osteoarthritis as well as in healthy subjects, by Western blotting and MS. In patients with RA, the relationship between the expression of the identified protein (inter-alpha-trypsin inhibitor heavy chain 4 [ITIH4]) and clinical features was evaluated, and the levels of citrullinated ITIH4 were compared before and after biological treatment. The antibody response against citrullinated ITIH4 peptide was measured by enzyme-linked immunosorbent assay.ResultsCitrullinated proteins were detected specifically in arthritic joints and sera from pGIA relative to controls. In sera, a common band of citrullinated protein at 120 kDa was revealed, and it fluctuated in parallel with arthritis score of pGIA by Western blotting. Interestingly, in 82% of RA patient sera, similar bands of citrullinated protein were specifically detected. These proteins were identified as citrullinated ITIH4, and especially the R438 site was commonly citrullinated between mice and humans. Citrullinated ITIH4 levels were associated with clinical parameters such as C-reactive protein (CRP), rheumatoid factor, and Disease Activity Score in 28 joints as measured by CRP in patients with RA. Its levels were decreased in correlation with the reduction of disease activity score after effective treatment in patients with RA. Moreover, antibody response to citrullinated epitope in ITIH4 was specifically observed in patients with RA.ConclusionsOur results suggest that serum citrullinated ITIH4 was specifically increased in patients with RA and could be a novel biomarker for assessing disease activity in patients with RA

    Different Infectivity and Transmissibility of H5N8 and H5N1 High Pathogenicity Avian Influenza Viruses Isolated from Chickens in Japan in the 2021/2022 Season

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    H5N8 and H5N1 high pathogenicity avian influenza viruses (HPAIVs) caused outbreaks in poultry farms in Japan from November 2021 to May 2022. Hemagglutinin genes of these viruses belong to clade 2.3.4.4B and can be divided phylogenetically into the following groups: 20A, 20E, and 21E. In this study, we compared the infectivity and transmissibility of HPAIVs from three groups of chickens. Representative strains from 20A, 20E, and 21E groups are A/chicken/Akita/7C/2021(H5N8)(Akita7C), A/chicken/Kagoshima/21A6T/2021(H5N1)(Kagoshima6T), and A/chicken/Iwate/21A7T/2022(H5N1)(Iwate7T), respectively. Fifty percent lethal dose of Akita7C in chickens (103.83 fifty percent egg infectious dose (EID50)) was up to seven times lower than those of Kagoshima6T and Iwate7T (104.50 and 104.68 EID50, respectively). Mean death times for Akita7C- and Kagoshima6T-infected chickens (3.45 and 3.30 days, respectively) were at least a day longer than that of Iwate7T (2.20 days). Viral titers of the trachea and cloaca of Iwate7T-infected chicken were the highest detected. The transmission rate of the Akita7C strain (100%) was markedly higher than those of the two strains (<50%). These data suggest that the infectivity and transmissibility of the Akita7C strain (H5N8) in chickens are higher than those of H5N1 viruses, providing fundamental information needed for formulating effective prevention and control strategies for HPAI outbreaks

    Different Infectivity and Transmissibility of H5N8 and H5N1 High Pathogenicity Avian Influenza Viruses Isolated from Chickens in Japan in the 2021/2022 Season

    No full text
    H5N8 and H5N1 high pathogenicity avian influenza viruses (HPAIVs) caused outbreaks in poultry farms in Japan from November 2021 to May 2022. Hemagglutinin genes of these viruses belong to clade 2.3.4.4B and can be divided phylogenetically into the following groups: 20A, 20E, and 21E. In this study, we compared the infectivity and transmissibility of HPAIVs from three groups of chickens. Representative strains from 20A, 20E, and 21E groups are A/chicken/Akita/7C/2021(H5N8)(Akita7C), A/chicken/Kagoshima/21A6T/2021(H5N1)(Kagoshima6T), and A/chicken/Iwate/21A7T/2022(H5N1)(Iwate7T), respectively. Fifty percent lethal dose of Akita7C in chickens (103.83 fifty percent egg infectious dose (EID50)) was up to seven times lower than those of Kagoshima6T and Iwate7T (104.50 and 104.68 EID50, respectively). Mean death times for Akita7C- and Kagoshima6T-infected chickens (3.45 and 3.30 days, respectively) were at least a day longer than that of Iwate7T (2.20 days). Viral titers of the trachea and cloaca of Iwate7T-infected chicken were the highest detected. The transmission rate of the Akita7C strain (100%) was markedly higher than those of the two strains (<50%). These data suggest that the infectivity and transmissibility of the Akita7C strain (H5N8) in chickens are higher than those of H5N1 viruses, providing fundamental information needed for formulating effective prevention and control strategies for HPAI outbreaks

    Live Cell Labeling with Terpyridine Derivative Proligands to Measure Cytotoxicity Mediated by Immune Cells

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    Immunotherapy using immune checkpoint inhibitors and CAR-T cells has revolutionized treatment for patients with malignant tumors. However, measuring tumor cell cytotoxicity mediated by immune effector cells in clinical laboratories has been difficult due to the requirement for radioactive substances. In this study, a series of novel terpyridine derivative proligands were synthesized, and a non-radioactive cellular cytotoxicity assay using the newly synthesized compounds was developed for use in preclinical and clinical studies for cancer immunotherapy. Once internalized into target cells, the compounds are hydrolyzed by esterases, resulting in the intracellular accumulation of the negatively charged terpyridine derivatives. When the labeled target cells are recognized and killed by immune effector cells, the integrity of the cell membrane is disrupted, and the terpyridine derivatives are released. Upon combining the culture supernatant with europium (Eu3+), the cytotoxicity of immune effector cells for the target cells can be quantitatively determined by measuring the intensity of the Eu3+/ligand-derived time-resolved fluorescence. Thus, the assay developed in this study would facilitate the development of novel cancer immunotherapies

    Establishment of Novel Reporter Cells Stably Maintaining Transcription Factor-driven Human Secreted Alkaline Phosphatase Expression

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    Background: Transcriptional regulation is a very important and pivotal function in myriad biological responses. Thus, methods to determine transcriptional activity are required in not only basic medical research but also in drug discovery. We established novel reporter constructs using human secreted embryonic alkaline phosphatase (SEAP) and Epstein-Barr virus nuclear antigen (EBNA) 1, which can maintain constructs synchronized to host cell replication. Methods: We established nuclear factor-kappa B (NFkB) or interferon regulatory factor (IRF) driven SEAP expression constructs and then, introduced them into culture cells. Results: The cells maintain reporter constructs for a long period in the culture and produce SEAP into culture supernatant in response to each specific ligand such as lipopolysaccharide (LPS) and inter-feron-beta. Measuring SEAP with chemiluminescence makes it possible to get high standard dynamic range applying to high-throughput screening in drug discovery in both 96 and 384 well format. We can also use it to determine transcriptional activity in the cells transfected with expression plasmid or treated with various toll-like receptor (TLR) ligands in a concentration-dependent manner and time-dependent manner. Finally, we demonstrated drug screening using a number of natural products library. Conclusion: We for the first time established the two novel reporter cells and validated their quality and accuracy enough to carry out drug screening

    Low plasma tryptophan is associated with olfactory function in healthy elderly community dwellers in Japan

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    Abstract Background Decreased circulating tryptophan (Trp) levels are frequently observed in elderly patients with neurodegenerative disease including Alzheimer’s disease. Trp may serve as a potential biomarker for monitoring disease risk in elderly people. We aimed to investigate the association between low plasma Trp levels and olfactory function, which is known to predict age-related diseases including dementia in elderly people. Methods A total of 144 healthy elderly Japanese community (≥ 65 years old) dwellers from the Health, Aging and Nutritional Improvement study (HANI study) were the subjects of our analysis. Low Trp levels were classified using the lower limit values of the reference interval according to a previous report. Olfactory function was assessed using a card-type test called Open Essence, which includes 12 odour items that are familiar to Japanese people. The elderly subjects with low circulating Trp levels were compared to a control group with normal plasma Trp levels. Results We conducted the analyses using 144 people aged 65 years or older (mean age 73.7 ± 5.5 years; 36.1% men). The subjects showed normal serum albumin levels (4.4 ± 0.2 g/dL) and no daily living disabilities. Low plasma Trp levels (low Trp group) were found in 11.1% of the study population. The low Trp group showed a significantly lower correct-answer rate for the items india ink, perfume, curry and sweaty smelling socks than control group (P < 0.05). There was also a significant association between low Trp levels and low olfactory ability, after adjusting for age and sex. Conclusions Lower plasma Trp levels were associated with a decrease in olfactory function in functionally competent older individuals. Because olfactory dysfunction predicts age-related diseases, low plasma Trp levels may represent a clinical sign of disease risk in elderly people
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