Publications by authors named "Kuramasu A"

Unlabelled: The concept of genome-microbiome interactions, in which the microenvironment determined by host genetic polymorphisms regulates the local microbiota, is important in the pathogenesis of human disease. In otolaryngology, the resident bacterial microbiota is reportedly altered in non-infectious ear diseases, such as otitis media pearls and exudative otitis media. We hypothesized that a single-nucleotide polymorphism in the ATP-binding cassette sub-family C member 11 () gene, which determines earwax properties, regulates the ear canal microbiota.

View Article and Find Full Text PDF

Gut bacteria play pivotal roles in the antitumor effects of immune checkpoint inhibitors (ICIs). However, antimicrobial therapy, often necessary for infections in cancer patients, can reduce the efficacy of ICIs. The potential of probiotics to restore ICI efficacy remains uncertain.

View Article and Find Full Text PDF
Article Synopsis
  • Natural killer group 2 member D ligands (NKG2DLs) in cancer cells can either activate immune responses or help tumors evade them, depending on their levels in the cells.
  • In pancreatic cancer cells (PANC-1), soluble MICB (sMICB) is found in the culture supernatant, which may saturate NKG2D T cells and inhibit their activation by membrane-bound MICB (mMICB).
  • Inhibiting the enzyme ADAM17, which contributes to the shedding of MICB, can help maintain mMICB expression and enhance NKG2D T cell activation, demonstrating a potential strategy to improve anti-tumor immune responses.
View Article and Find Full Text PDF

The low response rate of immune checkpoint inhibitors (ICIs) is a challenge. The efficacy of ICIs is influenced by the tumour microenvironment, which is controlled by the gut microbiota. In particular, intestinal bacteria and their metabolites, such as short chain fatty acids (SCFAs), are important regulators of cancer immunity; however, our knowledge on the effects of individual SCFAs remains limited.

View Article and Find Full Text PDF
Article Synopsis
  • Researchers explored the relationship between intestinal bacteria and postoperative recurrence in esophageal cancer patients after preoperative chemotherapy.
  • They used 16S rRNA metagenome sequencing and machine learning analysis to identify specific bacteria linked to cancer recurrence.
  • The study highlighted Butyricimonas and Actinomyces as potentially significant biomarkers, with Butyricimonas suggested as a factor in postoperative recurrence, warranting further investigation into their immune regulation roles.
View Article and Find Full Text PDF
Article Synopsis
  • Immune checkpoint inhibitors, like PD-1 inhibitors, have changed cancer treatment, but only 10%-30% of patients with solid tumors respond well to these therapies.
  • This study investigated how the occupancy of the PD-1 receptor in different T-cell populations, particularly effector regulatory T cells (eTregs), relates to patient outcomes and adverse effects in people treated with the drug nivolumab.
  • Findings showed that lower PD-1 occupancy on eTregs was linked to better clinical outcomes and lower mortality, suggesting that managing PD-1 signaling in these cells could enhance the effectiveness of cancer therapies.
View Article and Find Full Text PDF

Introduction: Immune checkpoint inhibitors have had a major impact on cancer treatment. Gut microbiota plays a major role in the cancer microenvironment, affecting treatment response. The gut microbiota is highly individual, and varies with factors, such as age and race.

View Article and Find Full Text PDF

Proper management of adverse events is crucial for the safe and effective implementation of anticancer drug treatment. Showa University Hospital uses our interview sheet (assessment and risk control [ARC] sheet) for the accurate evaluation of adverse events. On the day of anticancer drug treatment, a nurse conducts a face-to-face interview.

View Article and Find Full Text PDF
Article Synopsis
  • - The study investigates how antibiotic use affects the outcomes of patients with non-small cell lung cancer (NSCLC) undergoing anti-PD-1 immunotherapy, noting a trend toward increased antibiotic prescriptions for these patients.
  • - Among 69 patients analyzed, those who received antibiotics around the time of starting anti-PD-1 therapy experienced significantly worse outcomes, including lower objective response rates and shorter overall and progression-free survival.
  • - The findings indicate that antibiotic treatment is a negative predictive factor for progression-free survival, suggesting that combining antibiotics with anti-PD-1 therapy should be avoided in NSCLC patients.
View Article and Find Full Text PDF

Histamine induces chemotaxis of mast cells through the histamine H receptor. This involves the activation of small GTPases, Rac1 and Rac2, downstream of phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K). Activation of the H receptor also results in phospholipase C (PLC)-mediated calcium mobilization; however, it is unclear whether the PLC‑calcium pathway interacts with the PI3K-Rac pathway.

View Article and Find Full Text PDF

Histamine induces chemotaxis of mast cells through the H receptor. However, little is known about the precise intracellular signaling pathway that mediates this process. In this study, we identified small GTPases Rac1 and Rac2 as intracellular binding partners of the H receptor and characterized their roles in H receptor signaling.

View Article and Find Full Text PDF

UL16 binding protein 1 (ULBP1) expressed on the tumor cell surface binds to the natural killer group 2 member D (NKG2D) receptor presenting on natural killer (NK), cluster of differentiation (CD)8 T, and γ δ T cells. However, the roles of ULBP1 and NKG2D expression and associated immune responses in gastric cancer are unclear. The present study investigated the associations between ULBP1 and NKG2D expression and clinical outcomes in patients with gastric cancer.

View Article and Find Full Text PDF

Background/aim: We investigated the relationship between the expression of natural killer group 2, member D ligands (NKG2DLs) and the antitumor effects of protein-bound polysaccharide-K (PSK).

Materials And Methods: PSK was administered to evaluate its effectiveness against tumor growth. The expression of Rae-1 and H60 were analyzed in multiple cell lines.

View Article and Find Full Text PDF

Cancer stem-like cells (CSLCs) in solid tumors are thought to be resistant to conventional chemotherapy or molecular targeting therapy and to contribute to cancer recurrence and metastasis. In this study, we aimed to identify a biomarker of pancreatic CSLCs (P-CSLCs). A P-CSLC-enriched population was generated from pancreatic cancer cell lines using our previously reported method and its protein expression profile was compared with that of parental cells by 2-D electrophoresis and tandem mass spectrometry.

View Article and Find Full Text PDF

Background/aim: The purpose of the present study was to establish an effective immunotherapy by skewing the cosignal balance to be on the positive side by using the combination of monoclonal antibody (mAb) against 4-1BB also known as Cluster of Differentiation (CD) 137 as a co-stimulatory effector and to programmed death-1 (PD-1) to blockade the immune checkpoint.

Materials And Methods: Mice implanted with 1×10(5) CT26 cells were treated with anti 4-1BB mAb alone, anti PD-1 mAb alone, or both anti 4-1BB mAb and anti PD-1 mAb. Immune cell populations were analyzed by flow cytometry.

View Article and Find Full Text PDF

Cancer stem cells (CSCs) have been studied for their self-renewal capacity and pluripotency, as well as their resistance to anticancer therapy and their ability to metastasize to distant organs. CSCs are difficult to study because their population is quite low in tumor specimens. To overcome this problem, we established a culture method to induce a pancreatic cancer stem-like cell (P-CSLC)-enriched population from human pancreatic cancer cell lines.

View Article and Find Full Text PDF

Background: In the tumor microenvironment, factors inhibiting the targeting of cancer cells by activated T cells have recently been noted. B7-H3 belongs to the B7 superfamily of immune regulatory ligands and plays an important role in the adaptive immune response of co-inhibitory/stimulatory factors in regulating T cells. However, the degree to which B7-H3 directly affects tumor immune evasion mechanisms remains unclear, particularly in patients with breast cancer.

View Article and Find Full Text PDF

Erythropoiesis, the production of red blood cells, must be tightly controlled to ensure adequate oxygen delivery to tissues without causing thrombosis or stroke. Control of physiologic and pathologic erythropoiesis is dependent predominantly on erythropoietin (EPO), the expression of which is regulated by hypoxia-inducible factor (HIF) activity in response to low oxygen tension. Accumulating evidence indicates that oxygen-independent mediators, including inflammatory stimuli, cytokines, and growth factors, also upregulate HIF activity, but it is unclear whether these signals also result in EPO production and erythropoiesis in vivo.

View Article and Find Full Text PDF

Genetic engineering of tumor cells to express immune-stimulatory molecules, including cytokines and co-stimulatory ligands, is a promising approach to generate highly efficient cancer vaccines. The co-signaling molecule, LIGHT, is particularly well suited for use in vaccine development as it delivers a potent co-stimulatory signal through the Herpes virus entry mediator (HVEM) receptor on T cells and facilitates tumor-specific T cell immunity. However, because LIGHT binds two additional receptors, lymphotoxin β receptor and Decoy receptor 3, there are significant concerns that tumor-associated LIGHT results in both unexpected adverse events and interference with the ability of the vaccine to enhance antitumor immunity.

View Article and Find Full Text PDF

Functional roles of putative helix 8 in the carboxy-terminal tail of the human histamine H(3) receptor were investigated using deleted and alanine-substituted mutant receptors. While the deletion of the carboxy-terminal tail did not decrease the total expression level, surface expression, or ligand binding affinity, the agonist-stimulated cAMP response, [((35))S] GTPγS binding, and MAPK activation were totally abolished. The receptor lacking the carboxy-terminal tail also failed to respond to an inverse agonist, thioperamide, suggesting that the carboxy-terminal tail is involved in the regulation of receptor activity by changing G-protein coupling with the receptor.

View Article and Find Full Text PDF

B and T lymphocyte attenuator (BTLA) is a co-inhibitory receptor that interacts with herpesvirus entry mediator (HVEM), and this interaction regulates pathogenesis in various immunologic diseases. In graft-versus-host disease (GVHD), BTLA unexpectedly mediates positive effects on donor T-cell survival, whereas immunologic mechanisms of this function have yet to be explored. In this study, we elucidated a role of BTLA in GVHD by applying the newly established agonistic anti-BTLA monoclonal antibody that stimulates BTLA signal without antagonizing BTLA-HVEM interaction.

View Article and Find Full Text PDF

Sleep deprivation induces several negative effects on behavior, emotion, attention, and learning ability. Sleep appears to be particularly important during adolescent brain development. In the present study, we examined the effects of sleep deprivation on behavior and hypothalamic neurotransmission including histamine and orexin neurons in adolescent rats using the treadmill method.

View Article and Find Full Text PDF

T-cell tolerance is the central program that prevents harmful immune responses against self-antigens, in which inhibitory PD-1 signal given by B7-H1 interaction plays an important role. Recent studies demonstrated that B7-H1 binds CD80 besides PD-1, and B7-H1/CD80 interaction also delivers inhibitory signals in T cells. However, a role of B7-H1/CD80 signals in regulation of T-cell tolerance has yet to be explored.

View Article and Find Full Text PDF

Leucocyte-associated immunoglobulin-like receptor-1 (LAIR-1) is a membrane receptor of the immunoglobulin (Ig) superfamily that is expressed on most types of haematopoietic cells, and delivers inhibitory signals through interacting with collagens. In order to elucidate the immunological functions of LAIR-1 in vivo, we established transgenic mice expressing a chimeric protein composed of the extracellular domain of LAIR-1 fused with an Ig tag (LAIR-1-Ig), which acts as a decoy by competing with endogenous LAIR-1. The transgenic mice showed an increased susceptibility for development of contact hypersensitivity (CHS), an experimental model of allergic contact dermatitis, in association with enhanced hapten-specific T-cell responses.

View Article and Find Full Text PDF

Methamphetamine (METH) is often abused as a psychostimulant, and its administration induces several abnormal behaviors. We propose that neuronal histamine has an inhibitory role on the METH-induced locomotor hyperactivity and development of behavioral sensitization. We examined the roles of the histaminergic neuron system on behavioral sensitization and conditioned place preference (CPP) induced by METH using single and multiple histamine receptors deficient mice.

View Article and Find Full Text PDF