Antitumor immunity as the basis for durable disease-free treatment-free survival in patients with metastatic urothelial cancer.

Cisplatin-based chemotherapy has been associated with durable disease control in a small subset of patients with metastatic urothelial cancer. However, the mechanistic basis for this phenomenon has remained elusive. Antitumor immunity may underlie these exceptional responders.

Tumor-resident regulatory T cells in pancreatic cancer express the αvβ5 integrin as a targetable activation marker.

Pancreatic ductal adenocarcinoma (PDAC) has abundant immunosuppressive regulatory T cells (Tregs), which contribute to a microenvironment resistant to immunotherapy. Here, we report that Tregs in the PDAC tissue, but not those in the spleen, express the αvβ5 integrin in addition to neuropilin-1 (NRP-1), which makes them susceptible to the iRGD tumor-penetrating peptide, which targets cells positive for αv integrin- and NRP-1. As a result, long-term treatment of PDAC mice with iRGD leads to tumor-specific depletion of Tregs and improved efficacy of immune checkpoint blockade.

Dysfunction of CD8 + PD-1 + T cells in type 2 diabetes caused by the impairment of metabolism-immune axis.

The metabolic changes and dysfunction in CD8 + T cells may be involved in tumor progression and susceptibility to virus infection in type 2 diabetes (T2D). In C57BL/6JJcl mice fed with high fat-high sucrose chow (HFS), multifunctionality of CD8 + splenic and tumor-infiltrating lymphocytes (TILs) was impaired and associated with enhanced tumor growth, which were inhibited by metformin. In CD8 + splenic T cells from the HFS mice, glycolysis/basal respiration ratio was significantly reduced and reversed by metformin.

Berberine improved experimental chronic colitis by regulating interferon-γ- and IL-17A-producing lamina propria CD4 T cells through AMPK activation.

The herbal medicine berberine (BBR) has been recently shown to be an AMP-activated protein kinase (AMPK) productive activator with various properties that induce anti-inflammatory responses. We investigated the effects of BBR on the mechanisms of mucosal CD4T cell activation in vitro and on the inflammatory responses in T cell transfer mouse models of inflammatory bowel disease (IBD). We examined the favorable effects of BBR in vitro, using lamina propria (LP) CD4 T cells in T cell transfer IBD models in which SCID mice had been injected with CD4CD45RB T cells.

Metformin induces CD11b+-cell-mediated growth inhibition of an osteosarcoma: implications for metabolic reprogramming of myeloid cells and anti-tumor effects.

CD11b+ myeloid subpopulations, including myeloid-derived suppressor cells (MDSCs) and tumor-associated macrophages (TAMs), play crucial roles in the suppression of T-cell-mediated anti-tumor immunity. Regulation of these cell types is a primary goal for achieving efficient cancer immunotherapy. We found that metformin (Met) induces CD11b+-cell-mediated growth inhibition of a K7M2neo osteosarcoma independent of T cells, as growth inhibition of K7M2neo was still observed in wild-type (WT) mice depleted of T cells by antibodies and in SCID; this contrasted with the effect of Met on Meth A fibrosarcoma, which was entirely T-cell-dependent.

[Metabolic Competition in Tumor Microenvironment].

Metabolic pathways tightly regulate T cell response in host defense against infection and cancer. Glycolysis plays a key role in effector T cell differentiation and its function. More recent studies have demonstrated that tumor microenvironment forms hypoxia and metabolic disadvantage of immune cells.

Attenuation of CD4CD25 Regulatory T Cells in the Tumor Microenvironment by Metformin, a Type 2 Diabetes Drug.

CD4CD25 regulatory T cells (Treg), an essential subset for preventing autoimmune diseases, is implicated as a negative regulator in anti-tumor immunity. We found that metformin (Met) reduced tumor-infiltrating Treg (Ti-Treg), particularly the terminally-differentiated CD103KLRG1 population, and also decreased effector molecules such as CTLA4 and IL-10. Met inhibits the differentiation of naïve CD4 T cells into inducible Treg (iTreg) by reducing forkhead box P3 (Foxp3) protein, caused by mTORC1 activation that was determined by the elevation of phosphorylated S6 (pS6), a downstream molecule of mTORC1.

[Metformin-dependent metabolic reprogramming contributes to efficient anti-tumor immunity].

The rate of cancer incidence and mortality of Type 2 diabetes patients who were taking metformin seem to be decreased, comparing with those taking other drugs. We recently pro- vided compelling evidence showing that the effect might be mediated by immune system, thus, the reversion of exhausted tumor infiltrating CD8T lymphocytes (CD8TIL). Glycolysis is essential in CD8T cell function.

Study about the Efficacy of Metformin to Immune Function in Cancer Patients.

A study to evaluate the effect of metformin on the immune system was commenced in July 2014. Metformin is one of the most commonly prescribed drugs for type 2 diabetes, and previous studies have reported that metformin has an anti-tumor effect. The aim of this study is to evaluate the efficacy of metformin on the immune system in human cancer patients in vivo.

Detection and Tracking of NY-ESO-1-Specific CD8+ T Cells by High-Throughput T Cell Receptor β (TCRB) Gene Rearrangements Sequencing in a Peptide-Vaccinated Patient.

Comprehensive immunological evaluation is crucial for monitoring patients undergoing antigen-specific cancer immunotherapy. The identification and quantification of T cell responses is most important for the further development of such therapies. Using well-characterized clinical samples from a high responder patient (TK-f01) in an NY-ESO-1f peptide vaccine study, we performed high-throughput T cell receptor β-chain (TCRB) gene next generation sequencing (NGS) to monitor the frequency of NY-ESO-1-specific CD8+ T cells.

Immune-mediated antitumor effect by type 2 diabetes drug, metformin.

Metformin, a prescribed drug for type 2 diabetes, has been reported to have anti-cancer effects; however, the underlying mechanism is poorly understood. Here we show that this mechanism may be immune-mediated. Metformin enabled normal but not T-cell-deficient SCID mice to reject solid tumors.

Increase in activated Treg in TIL in lung cancer and in vitro depletion of Treg by ADCC using an antihuman CCR4 mAb (KM2760).

Introduction: Tregs infiltrate tumors and inhibit immune responses against them.

Methods: We investigated subpopulations of Foxp3 CD4 T cells previously defined by Miyara et al. (Immunity 30, 899-911, 2009) in peripheral blood mononuclear cells (PBMCs) and tumor infiltrating lymphocytes (TILs) in lung cancer.

[Regulation of T-cell immune exhaustion and cancer immunotherapy].

In chronic infectious diseases and cancer, CD8⁺ T cells specific for viral and/or tumor antigens undergo repeated T cell receptor (TCR) stimulation due to the persistence of pathogens or cancer cells, gradually losing their ability to secrete interleukin 2 (IL-2), tumor necrosis factor-a (TNF-a), and interferon-g (IFN-g). These CD8⁺ T cells are finally eliminated by apoptosis, a process referred to as immune exhaustion. The worsening immune function is accompanied by phenotypic changes in CD8⁺ T cells, for example, by changes in the expression of exhaustion markers such as programmed cell death protein 1(PD-1), cytotoxic T-lymphocyte antigen 4 (CTLA-4), T cell immunoglobulin mucin 3 (TIM-3), and lymphocyte activation gene 3 (LAG-3).

Monitoring multifunctionality of immune-exhausted CD8 T cells in cancer patients.

CD8 T cells play a critical role in the host defense against cancers and infectious diseases. However, the presence of antigen-specific CD8 T cells does not always imply that cancers and/or pathogens are efficiently eliminated in the body. Concerning this point, the recent studies suggest the concept of immune exhaustion of CD8 T cells, characterized by their decreased production of IL-2, TNFα, and IFNγ even after antigen stimulation.

Vaccination with NY-ESO-1 overlapping peptides mixed with Picibanil OK-432 and montanide ISA-51 in patients with cancers expressing the NY-ESO-1 antigen.

We conducted a clinical trial of an NY-ESO-1 cancer vaccine using 4 synthetic overlapping long peptides (OLP; peptides #1, 79-108; #2, 100-129; #3, 121-150; and #4, 142-173) that include a highly immunogenic region of the NY-ESO-1 molecule. Nine patients were immunized with 0.25 mg each of three 30-mer and a 32-mer long NY-ESO-1 OLP mixed with 0.

HSP70 and HSP90 Differentially Regulate Translocation of Extracellular Antigen to the Cytosol for Cross-Presentation.

Antigens (Ag) from cancer or virus-infected cells must be internalized by dendritic cells (DCs) to be presented to CD8(+) T cells, which eventually differentiate into Ag-specific cytotoxic T lymphocytes (CTLs) that destroy cancer cells and infected cells. This pathway is termed cross-presentation and is also implicated as an essential step in triggering autoimmune diseases such as Type I diabetes. Internalized Ag locates within endosomes, followed by translocation through a putative pore structure spanning endosomal membranes into the cytosol, where it is degraded by the proteasome to generate antigen peptides.

Induction of CD8 T-cell responses restricted to multiple HLA class I alleles in a cancer patient by immunization with a 20-mer NY-ESO-1f (NY-ESO-1 91-110) peptide.

Immunogenicity of a long 20-mer NY-ESO-1f peptide vaccine was evaluated in a lung cancer patient TK-f01, immunized with the peptide with Picibanil OK-432 and Montanide ISA-51. We showed that internalization of the peptide was necessary to present CD8 T-cell epitopes on APC, contrasting with the direct presentation of the short epitope. CD8 T-cell responses restricted to all five HLA class I alleles were induced in the patient after the peptide vaccination.

Spontaneous antibody, and CD4 and CD8 T-cell responses against XAGE-1b (GAGED2a) in non-small cell lung cancer patients.

The spontaneous immune responses against XAGE-1b (GAGED2a) were analyzed in non-small cell lung cancer (NSCLC) patients. An antibody response against XAGE-1b (GAGED2a) was observed in 10% (20/200) of NSCLC patients and in 19% (13/69) of stage IIIB/IV lung adenocarcinoma patients. A CD4 T-cell response was detected in 88% (14/16) and a CD8 T-cell response in 67% (6/9) in the XAGE-1b (GAGED2a) antibody-positive patients examined.

Enrichment of Foxp3+ CD4 regulatory T cells in migrated T cells to IL-6- and IL-8-expressing tumors through predominant induction of CXCR1 by IL-6.

Analysis of cytokine and chemokine production by tumor cell lines including five lung cancers, a malignant mesothelioma, and a malignant melanoma recently established in our laboratory showed rather high production of IL-8 in all tumors and IL-6 in one lung cancer, the malignant mesothelioma, and the malignant melanoma. We investigated the migration of PBMCs to these tumor cells using Transwell plates and showed enrichment of Foxp3(+) CD4 regulatory T cells (Tregs) in migrated T cells to both IL-6- and IL-8-producing tumors. Marked induction of CXCR1 expression on Foxp3(+) CD4 Tregs by IL-6 followed by IL-8-mediated migration appeared to be responsible for enriched migration.

Correlation of high and decreased NY-ESO-1 immunity to spontaneous regression and subsequent recurrence in a lung cancer patient.

We show correlation between strong and decreased NY-ESO-1-specific immunity with spontaneous regression and subsequent recurrence, respectively, in a long-surviving patient with an NY-ESO-1-expressing lung adenocarcinoma. An integrated immune response consisting of IgG antibody, as well as CD4 and CD8 T cells, against NY-ESO-1 was observed at the time of spontaneous regression of multiple pleural metastases. After tumor dormancy for 3 years, the tumor started to progress.