Junko Matsuzaki

mTOR inhibition modulates vaccine-induced immune responses to generate memory T cells in patients with solid tumors

Background Perturbation of the mechanistic target of rapamycin (mTOR) pathway can instruct effector versus memory cell fate of tumor antigen-specific T cells in preclinical models. In this study, we sought to understand the impact of rapamycin (sirolimus), an mTOR inhibitor, on reprogramming vaccine-induced T cells to enhance memory responses in patients with solid tumors following completion of their standard therapy. Methods We conducted three phase I clinical trials employing New York esophageal squamous cell carcinoma-1 (NY-ESO-1) vaccination approaches, with or without schedule-varied rapamycin. T cell phenotypes, functions, and Vβ usage in peripheral blood were analyzed to ask whether rapamycin influenced the generation of vaccine-induced T cells with memory attributes. Results The addition of rapamycin to all vaccination approaches was safe and well tolerated. Immediate (days 1–14 postvaccination) or delayed (days 15–28 postvaccination) administration of rapamycin led to a significant increase in the generation of vaccine-induced NY-ESO-1-specific T cells exhibiting central memory phenotypes (CD45RO+CD45RA− CCR7+). Moreover, delayed administration resulted in a greater than threefold (p=0.025) and eightfold (p=0.005) increase in the frequency of NY-ESO-1-specific CD4+ T and CD8+ T cells respectively at the time of long-term follow-up, compared with its immediate usage. Conclusion Our novel finding is that delayed administration of rapamycin to patients during the contraction phase of vaccine-induced antitumor immune responses was particularly effective in increasing the frequency of memory T cells up to 1 year postvaccination in patients with solid tumors. Further studies are warranted to identify the impact of this approach on the durability of clinical remission. Trial registration number NCT00803569, NCT01536054, NCT01522820.

Cancer Relevance of Circulating Antibodies Against LINE-1 Antigens in Humans

Abstract Long interspersed nuclear element-1 (LINE-1 or L1), the most abundant family of autonomous retrotransposons occupying over 17% of human DNA, is epigenetically silenced in normal tissues by the mechanisms involving p53 but is frequently derepressed in cancer, suggesting that L1-encoded proteins may act as tumor-associated antigens recognized by the immune system. In this study, we established an immunoassay to detect circulating autoantibodies against L1 proteins in human blood. Using this assay in >2,800 individuals with or without cancer, we observed significantly higher IgG titers against L1-encoded ORF1p and ORF2p in patients with lung, pancreatic, ovarian, esophageal, and liver cancers than in healthy individuals. Remarkably, elevated levels of anti–ORF1p-reactive IgG were observed in patients with cancer with disease stages 1 and 2, indicating that the immune response to L1 antigens can occur in the early phases of carcinogenesis. We concluded that the antibody response against L1 antigens could contribute to the diagnosis and determination of immunoreactivity of tumors among cancer types that frequently escape early detection. Significance: The discovery of autoantibodies against antigens encoded by L1 retrotransposons in patients with five poorly curable cancer types has potential implications for the detection of an ongoing carcinogenic process and tumor immunoreactivity.

Metabolic adaptation of ovarian tumors in patients treated with an IDO1 inhibitor constrains antitumor immune responses

To uncover underlying mechanisms associated with failure of indoleamine 2,3-dioxygenase 1 (IDO1) blockade in clinical trials, we conducted a pilot, window-of-opportunity clinical study in 17 patients with newly diagnosed advanced high-grade serous ovarian cancer before their standard tumor debulking surgery. Patients were treated with the IDO1 inhibitor epacadostat, and immunologic, transcriptomic, and metabolomic characterization of the tumor microenvironment was undertaken in baseline and posttreatment tumor biopsies. IDO1 inhibition resulted in efficient blockade of the kynurenine pathway of tryptophan degradation and was accompanied by a metabolic adaptation that shunted tryptophan catabolism toward the serotonin pathway. This resulted in elevated nicotinamide adenine dinucleotide (NAD + ), which reduced T cell proliferation and function. Because NAD + metabolites could be ligands for purinergic receptors, we investigated the impact of blocking purinergic receptors in the presence or absence of NAD + on T cell proliferation and function in our mouse model. We demonstrated that A2a and A2b purinergic receptor antagonists, SCH58261 or PSB1115, respectively, rescued NAD + -mediated suppression of T cell proliferation and function. Combining IDO1 inhibition and A2a/A2b receptor blockade improved survival and boosted the antitumor immune signature in mice with IDO1 overexpressing ovarian cancer. These findings elucidate the downstream adaptive metabolic consequences of IDO1 blockade in ovarian cancers that may undermine antitumor T cell responses in the tumor microenvironment.

Identification of Claudin 6-specific HLA class I- and HLA class II-restricted T cell receptors for cellular immunotherapy in ovarian cancer

Adoptive cell therapy (ACT) is one of promising immunotherapies for cancer patients by providing a large amount of cancer antigen-specific effector T cells that can be manufactured rapidly by ex vivo gene engineering. To provide antigen-specificity to patients' autologous T cells in a short-term culture, T-cell receptors (TCRs) or chimeric antigen receptors (CARs) are transduced to bulk T cells. Because of intra- and inter-tumoral heterogeneity in tumor antigen expression, a repertoire of TCR or CAR genes targeting a wide range of tumor antigens are required for a broad and effective treatment by ACT. Here, we characterized immunogenicity of claudin 6 (CLDN6) in ovarian cancer patients and identified specific TCR genes from CD8

Sirolimus and Vaccine Therapy in Treating Patients With Stage II-IV Ovarian Epithelial, Fallopian Tube, or Primary Peritoneal Cavity Cancer

This phase I trial studies the side effects and best dose and schedule of sirolimus when given together with vaccine therapy in treating patients with stage II-IV ovarian epithelial, fallopian tube, or primary peritoneal cavity cancer. Sirolimus may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. Vaccines made from a gene-modified virus may help the body build an effective immune response to kill tumor cells. Giving vaccine therapy together with sirolimus may be an effective treatment for ovarian, fallopian tube, or primary peritoneal cancer

Vaccine Therapy With or Without Sirolimus in Treating Patients With NY-ESO-1 Expressing Solid Tumors

This phase I trial studies the side effects and best schedule of vaccine therapy with or without sirolimus in treating patients with cancer-testis antigen (NY-ESO-1) expressing solid tumors. Biological therapies, such as sirolimus, may stimulate the immune system in different ways and stop tumor cells from growing. Vaccines made from a person's white blood cells mixed with tumor proteins may help the body build an effective immune response to kill tumor cells that express NY-ESO-1. Infusing the vaccine directly into a lymph node may cause a stronger immune response and kill more tumor cells. It is not yet known whether vaccine therapy works better when given with or without sirolimus in treating solid tumors.

Vaccine Therapy in Stage II, III, or IV Epithelial Ovarian, Fallopian Tube, or Primary Peritoneal Cancers

This was a Phase 1, non-randomized, open-label, multicenter study of the ALVAC(2)-NY-ESO-1(M)/TRICOM vaccine administered with the granulocyte macrophage-colony stimulating factor (GM-CSF) sargramostim in patients with NY-ESO-1- or LAGE-1-positive epithelial ovarian, fallopian tube, or primary peritoneal cavity cancers who had completed standard therapy for primary or recurrent disease and would have normally entered a period of observation. The primary study objective was to determine the safety and tolerability of study vaccination, with secondary objectives including the determination of clinical and immunological responses.