Publications by authors named "Hiroshi Saijo"

Background/aim: Immunotherapy using immune checkpoint inhibitors (ICIs) has revolutionized the treatment of advanced non-small cell lung cancer (NSCLC). Although several ICI options are available, the treatment regimen for NSCLC with large size tumors (large NSCLC) is controversial and the efficacy of anti-CTLA-4 antibody is unclear. This study thus investigated potential biomarkers for CTLA-4 blockade.

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The immunogenicity of a T cell Ag is correlated with the ability of its antigenic epitope to bind HLA and be stably presented to T cells. This presents a challenge for the development of effective cancer immunotherapies, as many self-derived tumor-associated epitopes elicit weak T cell responses, in part due to weak binding affinity to HLA. Traditional methods to increase peptide-HLA binding affinity involve modifying the peptide to reflect HLA allele binding preferences.

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Peptide-major histocompatibility complex (pMHC) multimers enable the detection of antigen-specific T cells in studies ranging from vaccine efficacy to cancer immunotherapy. However, this technology is unreliable when applied to pMHC class II for the detection of CD4 T cells. Here, using a combination of molecular biological and immunological techniques, we cloned sequences encoding human leukocyte antigen (HLA)-DP, HLA-DQ and HLA-DR molecules with enhanced CD4 binding affinity (with a K of 8.

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Adoptive immunotherapy can induce sustained therapeutic effects in some cancers. Antitumor T-cell grafts are often individually prepared from autologous T cells, which requires an intensive workload and increased costs. The quality of the generated T cells can also be variable, which affects the therapy's antitumor efficacy and toxicity.

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HLA-restricted T cell responses can induce antitumor effects in cancer patients. Previous human T cell research has largely focused on the few HLA alleles prevalent in a subset of ethnic groups. Here, using a panel of newly developed peptide-exchangeable peptide/HLA multimers and artificial antigen-presenting cells for 25 different class I alleles and greater than 800 peptides, we systematically and comprehensively mapped shared antigenic epitopes recognized by tumor-infiltrating T lymphocytes (TILs) from eight melanoma patients for all their class I alleles.

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Recent work has delineated key differences in the antigen processing and presentation mechanisms underlying HLA-DP alleles encoding glycine at position 84 of the DPβ chain (DP). These DPs are unable to associate with the class II-associated Ii peptide (CLIP) region of the invariant chain (Ii) chaperone early in the endocytic pathway, leading to continuous presentation of endogenous antigens. However, little is known about the chaperone support involved in the loading of these endogenous antigens onto DP molecules.

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Forkhead box transcription factor 3 (FOXP3) plays a pivotal role in the suppressive function of regulatory T cells. In addition to mRNA levels, FOXP3 activity can also be controlled by posttranslational mechanisms, which have not been studied in a comprehensive manner. Through extensive screening using selective inhibitors, we demonstrate that the inhibition of type I protein arginine methytransferases (PRMTs) attenuates the suppressive functions of regulatory T cells.

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We present a case series of four siblings with hereditary hemorrhagic telangiectasia (HHT) and pulmonary arteriovenous malformations (PAVM). The patients' mother has HHT. Case 1: A 22-year-old man developed dyspnea and epistaxis.

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Chest wall tumors are relatively rare, and hematogenous metastasis to the chest wall is very rare. We herein describe a rare case of occult thyroid carcinoma as metastasis to the chest wall in an 80-year-old woman. The patient received detailed examinations of the chest wall tumor, and the results suggested that she had occult thyroid carcinoma.

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Cytotoxic T-lymphocytes (CTLs) lyse target cells after recognizing the complexes of peptides and MHC class I molecules (pMHC I) on cell surfaces. Tapasin is an essential component of the peptide-loading complex (PLC) and its absence influences the surface repertoire of MHC class I peptides. In the present study, we assessed tapasin expression in 85 primary tumor lesions of non-small cell lung cancer (NSCLC) patients, demonstrating that tapasin expression positively correlated with patient survival.

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Lung cancer is one of the most common malignancies with a high rate of mortality. Lung cancer stem-like cells (CSCs)/ cancer-initiating cells (CICs) play major role in resistance to treatments, recurrence and distant metastasis and eradication of CSCs/CICs is crucial to improve recent therapy. Cytotoxic T lymphocytes (CTLs) are major effectors of cancer immunotherapy, and CTLs recognize antigenic peptides derived from antigens that are presented by major histocompatibility complex (MHC) class I molecules.

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Cancer stem-like cells (CSCs)/cancer-initiating cells (CICs) are reasonable targets for cancer therapy. However, recent studies have revealed that some non-CSCs/CICs have plastic ability and can dedifferentiate into CSCs/CICs. Therefore, an understanding of the molecular mechanisms that control the plasticity is essential to achieve CSC/CIC-targeting therapy.

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Human cancer stem-like cells (CSCs)/cancer-initiating cells (CICs) can be isolated as side population (SP) cells, aldehyde dehydrogenase high (ALDHhigh) cells or cell surface marker-positive cells including CD44+ cells and CD133+ cells. CSCs/CICs and non-CSCs/CICs are unstable in in vitro culture, and CSCs/CICs can differentiate into non-CSCs/CICs and some non-CSCs/CICs can dedifferentiate into CSCs/CICs. Therefore, experiments using a large amount of CSCs/CICs are technically very difficult.

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Epithelial ovarian cancer (EOC) is one of the most lethal cancers in females. Cancer stem-like cells (CSCs)/cancer-initiating cells (CICs) have been reported to be origin of primary and recurrent cancers and to be resistant to several treatments. In this study, we identified matrix metalloproteinase-10 (MMP10) is expressed in CSCs/CICs of EOC.

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Cervical cancer is a major cause of cancer death in females worldwide. Cervical cancer stem-like cells (CSCs)/cancer-initiating cells (CICs) are resistant to conventional radiotherapy and chemotherapy, and CSCs/CICs are thought to be responsible for recurrence. Eradication of CSCs/CICs is thus essential to cure cervical cancer.

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Cancer stem-like cells (CSCs)/cancer-initiating cells (CICs) are defined as a small population of cancer cells that have self-renewal ability, differentiation ability and high tumor-initiating ability. CSCs/CICs are resistant to cancer therapies including chemotherapy and radiotherapy. Therefore, CSCs/CICs are thought to be responsible for cancer recurrence and distant metastasis after treatment.

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