Publications by authors named "Kenji Chamoto"

Despite the unprecedented therapeutic potential of immune checkpoint antibody therapies, their efficacy is limited partly by the dysfunction of T cells within the cancer microenvironment. Combination therapies with small molecules have also been explored, but their clinical implementation has been met with significant challenges. To search for antitumor immunity activators, the present study developed a cell-based system that emulates cancer-attenuated T cells.

View Article and Find Full Text PDF
Article Synopsis
  • T follicular helper (Tfh) cells, which are important for antibody production, rely heavily on the immunoreceptor PD-1, and its deficiency leads to weakened Tfh functions and impaired immune responses in mice.
  • Individuals lacking PD-1 or PD-L1 demonstrate fewer memory B cells and diminished antibody responses, highlighting the critical role of these molecules in immune system functionality.
  • PD-1 influences both the intrinsic and extrinsic aspects of B cell memory and antibody production, suggesting that disruptions in PD-1 signaling can lead to complications in immune responses, especially during anti-PD-1-PD-L1 therapies.
View Article and Find Full Text PDF
Article Synopsis
  • Cancer immunotherapy, especially PD-1 blockade, is less effective in older adults due to weakened T-cell immunity, which spermidine may help restore by boosting mitochondrial fatty acid oxidation (FAO).
  • Researchers developed a spermidine-based probe to identify spermidine-binding proteins and discovered 140 proteins involved, primarily in mitochondria, including key lipid metabolism proteins.
  • A synthetic compound named "spermimic" was found to enhance mitochondrial bioenergetics and improve PD-1 therapy in mice, indicating potential for small-molecule cancer treatments that could boost immune responses in patients.
View Article and Find Full Text PDF
Article Synopsis
  • Researchers studied immune-checkpoint molecules in the blood of advanced non-small cell lung cancer (NSCLC) patients to see how they correlate with response to PD-1/PD-L1 blockade therapy.
  • They found that higher levels of these immune factors, particularly in patients with immune-reactive tumors, were linked to a lack of response to therapy.
  • The study suggests combining measurements of soluble immune molecules with tumor characteristics can better predict which patients may not benefit from PD-1/PD-L1 blockade treatments.
View Article and Find Full Text PDF
Article Synopsis
  • The study investigates the clinical significance of soluble forms of programmed cell death-1 (sPD-1) and programmed cell death-ligand 1 (sPD-L1) in the context of cancer treatment effectiveness, specifically focusing on PD-1 blockade therapies.
  • Researchers analyzed data from 171 patients with various advanced solid tumors who received treatments like nivolumab or pembrolizumab to understand the relationship between plasma levels of sPD-1 and sPD-L1 and patient outcomes.
  • Results indicated that while sPD-1 and sPD-L1 levels alone weren't significantly linked to patient survival, a specific combination of low sPD-1 and high sPD-L1 was associated with poorer progression-free survival and a
View Article and Find Full Text PDF

Introduction: Perioperative treatment in NSCLC has gained marked attention with the introduction of immune checkpoint inhibitors. Such a paradigm shift has given us additional opportunities to evaluate potential biomarkers in patients with these curable disease stages.

Methods: This study (WJOG12319LTR) was designed as a biomarker study to evaluate whether soluble immune markers were prognostic or predictive on relapse-free survival in patients with stage II to IIIA NSCLC who underwent complete resection and adjuvant chemotherapy with cisplatin plus S-1, which is an oral fluoropyrimidine formulation that consists of tegafur, gimeracil, and oteracil, or S-1 alone in the previous WJOG4107 study.

View Article and Find Full Text PDF

Polyamines - putrescine, spermidine, and spermine - are widely distributed aliphatic compounds known to regulate important biological processes in prokaryotic and eukaryotic cells. Therefore, spermidine insufficiency is associated with various physio-pathological processes, such as aging and cancers. Recent advances in immuno-metabolism and immunotherapy shed new light on the role of spermidine in immune cell regulation and anticancer responses.

View Article and Find Full Text PDF

In the later stages of angiogenesis, the vascular sprout transitions into a functional vessel by fusing with a target vessel. Although this process appears to routinely occur in embryonic tissue, the biologic rules for sprout fusion and lumenization in adult regenerating tissue are unknown. To investigate this process, we grafted portions of the regenerating post-pneumonectomy lung onto the chick chorioallantoic membrane (CAM).

View Article and Find Full Text PDF

PD1 was originally discovered in 1992 as a molecule associated with activation-induced cell death in T cells. Over the past 30 years, it was found that PD1 has a critical role in avoiding overactivation-induced cell death and autoimmunity, whereas its inhibition unleashes anticancer immunity. Here, we outline the journey from the discovery of PD1 to its role as a breakthrough target in cancer immunotherapy.

View Article and Find Full Text PDF

Background: The clinical value of soluble forms of programmed cell death-1 (sPD-1), PD ligand 1 (sPD-L1) and cytotoxic T lymphocyte-associated protein-4 (sCTLA-4) for gastric cancer (GC) patients treated with nivolumab monotherapy has remained unknown.

Methods: Blood samples collected before nivolumab treatment from 439 GC patients enrolled in the DELIVER (Japan Clinical Cancer Research Organisation GC-08) trial were analysed for sPD-1, sPD-L1 and sCTLA-4. Corresponding baseline clinical data were also retrieved.

View Article and Find Full Text PDF
Article Synopsis
  • Cancer immunotherapies, like PD-1 and PD-L1 inhibitors, are effective but many patients develop resistance, highlighting the need for new combination therapies.
  • Bezafibrate, which activates certain receptors, shows promise when used with PD-1 blockade and has been tested in a phase 1 trial with nivolumab on patients with advanced non-small cell lung cancer.
  • Results indicate that this combination is well tolerated and may enhance T cell function by improving mitochondrial metabolism, suggesting potential for sustained antitumor activity that requires further study.
View Article and Find Full Text PDF

Neoantigen production is a determinant of cancer immunotherapy. However, the expansion of neoantigen abundance for cancer therapeutics is technically challenging. Here, we report that the synthetic compound RECTAS can induce the production of splice-neoantigens that could be used to boost antitumor immune responses.

View Article and Find Full Text PDF

Spermidine (SPD) delays age-related pathologies in various organisms. SPD supplementation overcame the impaired immunotherapy against tumors in aged mice by increasing mitochondrial function and activating CD8 T cells. Treatment of naïve CD8 T cells with SPD acutely enhanced fatty acid oxidation.

View Article and Find Full Text PDF
Article Synopsis
  • Small, soluble metabolites like GABA, produced by activated B cells, can influence nearby cells and play a role in immune responses.
  • GABA promotes the differentiation of monocytes into anti-inflammatory macrophages, which help suppress CD8 T cell activity and secrete interleukin-10.
  • Research shows that reducing B cell activity or GABA production can enhance anti-tumor responses, highlighting the potential of small metabolites as therapeutic targets for regulating the immune system.
View Article and Find Full Text PDF

The pathophysiology of adverse events following programmed cell death protein 1 (PD-1) blockade, including tuberculosis (TB) and autoimmunity, remains poorly characterized. We studied a patient with inherited PD-1 deficiency and TB who died of pulmonary autoimmunity. The patient's leukocytes did not express PD-1 or respond to PD-1-mediated suppression.

View Article and Find Full Text PDF

CD8 T cells play a central role in antitumor immune responses that kill cancer cells directly. In aged individuals, CD8 T cell immunity is strongly suppressed, which is associated with cancer and other age-related diseases. The mechanism underlying this age-related decrease in immune function remains largely unknown.

View Article and Find Full Text PDF

The gut microbiome has garnered attention as an effective target to boost immunity and improve cancer immunotherapy. We found that B cell-defective (BCD) mice, such as µ-membrane targeted deletion (µMT) and activation-induced cytidine deaminase (AID) knockouts (KOs), have elevated antitumor immunity under specific pathogen-free but not germ-free conditions. Microbial dysbiosis in these BCD mice enriched the type I IFN (IFN) signature in mucosal CD8 T cells, resulting in up-regulation of the type I IFN-inducible protein stem cell antigen-1 (Sca-1).

View Article and Find Full Text PDF

Energy metabolism plays an important role in proliferating cells. Recent reports indicate that metabolic regulation or metabolic products can control immune cell differentiation, fate and reactions. Cancer immunotherapy based on blockade of programmed cell death protein 1 (PD-1) has been used worldwide, but a significant fraction of patients remain unresponsive.

View Article and Find Full Text PDF

Immune checkpoint blockade inhibition is a therapy which interferes with inhibitory signals placed upon immune cells, thereby eliciting anti-tumor responses. Although programmed death-1(PD-1)blockade therapy has been shown to be highly effective in clinical use, certain population of patients still fail to respond. Therefore, it is critical to determine how therapeutic efficacy of checkpoint inhibition can be enhanced.

View Article and Find Full Text PDF

Chronic hepatitis B is now controllable when treated with nucleoside reverse transcriptase inhibitors (NRTIs), which inhibit hepatitis B virus (HBV) replication. However, once the NRTIs are discontinued, most patients relapse, necessitating lifelong NRTIs treatment. HBV infection relapse is assumed to be caused by the persistent existence of covalently closed circular DNA (cccDNA) in the nuclei of infected hepatocytes.

View Article and Find Full Text PDF

PD-1 blockade therapy has revolutionized cancer treatments. However, a substantial population of patients is unresponsive. To rescue unresponsive patients, the mechanism of unresponsiveness to PD-1 blockade therapy must be elucidated.

View Article and Find Full Text PDF

In classical Hodgkin lymphoma (cHL)-characterized by the presence of Hodgkin and Reed-Sternberg (HRS) cells-tumor-associated macrophages (TAMs) play a pivotal role in tumor formation. However, the significance of direct contact between HRS cells and TAMs has not been elucidated. HRS cells and TAMs are known to express PD-L1, which leads to PD-1 CD4 T cell exhaustion in cHL.

View Article and Find Full Text PDF

Programmed cell death 1 (PD-1) signal receptor blockade has revolutionized the field of cancer therapy. Despite their considerable potential for treating certain cancers, drugs targeting PD-1 still present two main drawbacks: the substantial number of unresponsive patients and/or patients showing recurrences, and side effects associated with the autoimmune response. These drawbacks highlight the need for further investigation of the mechanisms underlying the therapeutic effects, as well as the need to develop novel biomarkers to predict the lack of treatment response and to monitor potential adverse events.

View Article and Find Full Text PDF

BACKGROUNDCurrent clinical biomarkers for the programmed cell death 1 (PD-1) blockade therapy are insufficient because they rely only on the tumor properties, such as programmed cell death ligand 1 expression frequency and tumor mutation burden. Identifying reliable, responsive biomarkers based on the host immunity is necessary to improve the predictive values.METHODSWe investigated levels of plasma metabolites and T cell properties, including energy metabolism markers, in the blood of patients with non-small cell lung cancer before and after treatment with nivolumab (n = 55).

View Article and Find Full Text PDF
Article Synopsis
  • * Important immune checkpoint molecules like PD-1, PD-L1, and CTLA-4 are crucial for understanding patients' immune states, but current testing methods have issues with sensitivity and reproducibility.
  • * A new automated immunoassay system using chemiluminescent magnetic technology has been developed, showing improved sensitivity and accuracy in measuring soluble PD-1, PD-L1, and CTLA-4 levels in cancer patients' plasma compared to healthy individuals.
View Article and Find Full Text PDF

Synopsis of recent research by authors named "Kenji Chamoto"

  • - Kenji Chamoto's recent research focuses on immune checkpoint inhibitors and their interactions with various biomarkers in cancer therapy, specifically evaluating the roles of soluble PD-1 and PD-L1 in non-small cell lung cancer and other advanced cancers to improve patient stratification for PD-1 blockade therapies.
  • - His work with spermidine explores its potential in enhancing antitumor immunity by promoting mitochondrial fatty acid oxidation, suggesting a link between this biogenic polyamine and the restoration of immune function in aging patients.
  • - Additionally, Chamoto investigates the use of combination therapies, such as bezafibrate with nivolumab, to overcome resistance in cancer immunotherapy, highlighting new strategies to enhance the effectiveness of existing treatments.