Publications by authors named "Ayako W Pedersen"

Background: Arginase-1-producing cells inhibit T cell-mediated anti-tumor responses by reducing L-arginine levels in the tumor microenvironment. T cell-facilitated elimination of arginase-1-expressing cells could potentially restore L-arginine levels and improve anti-tumor responses. The activation of arginase-1-specific T cells may convert the immunosuppressive tumor microenvironment and induce or strengthen local Th1 inflammation.

View Article and Find Full Text PDF
Article Synopsis
  • The tumor microenvironment (TME) is immunosuppressive, primarily due to the presence of the IDO enzyme, which is produced by cancer cells and certain immune cells, hindering the generation of antitumor cells.
  • An IDO-specific peptide vaccine was developed to target IDO+ cells while preserving the function of IDO- immune cells, yielding promising results in mouse models of melanoma (B16F10) and non-IDO tumors (TC-1).
  • The IDO vaccine effectively reduced tumor growth and increased survival by promoting the proliferation of immune cells and decreasing immunosuppressive factors within the TME, enhancing overall antitumor effectiveness.
View Article and Find Full Text PDF

Anti-programmed death (PD)-1 (aPD1) therapy is an effective treatment for metastatic melanoma (MM); however, over 50% of patients progress due to resistance. We tested a first-in-class immune-modulatory vaccine (IO102/IO103) against indoleamine 2,3-dioxygenase (IDO) and PD ligand 1 (PD-L1), targeting immunosuppressive cells and tumor cells expressing IDO and/or PD-L1 (IDO/PD-L1), combined with nivolumab. Thirty aPD1 therapy-naive patients with MM were treated in a phase 1/2 study ( https://clinicaltrials.

View Article and Find Full Text PDF
Article Synopsis
  • Immune checkpoint blocking antibodies targeting PD-1 have shown activity against basal cell carcinoma (BCC), and the IO103 peptide vaccine aims to enhance this response by targeting the PD-L1 ligand.
  • A phase IIa study evaluated IO103 with Montanide adjuvant in ten patients with resectable BCC, focusing on clinical responses, tumor size changes, and immune responses after vaccinations.
  • Results indicated promising findings with partial and complete responses in both target and non-target tumors, minimal adverse effects, and evidence of immune activation, suggesting IO103 could be beneficial for a specific subtype of BCC.
View Article and Find Full Text PDF

Transforming growth factor-beta (TGFβ) is a highly potent immunosuppressive cytokine. Although TGFβ is a tumor suppressor in early/premalignant cancer lesions, the cytokine has several tumor-promoting effects in advanced cancer; abrogation of the antitumor immune response is one of the most important tumor-promoting effects. As several immunoregulatory mechanisms have recently been shown to be targets of specific T cells, we hypothesized that TGFβ is targeted by naturally occurring specific T cells and thus could be a potential target for immunomodulatory cancer vaccination.

View Article and Find Full Text PDF

One way that tumors evade immune destruction is through tumor and stromal cell expression of arginine-degrading enzyme arginase-2 (ARG2). Here we describe the existence of pro-inflammatory effector T-cells that recognize ARG2 and can directly target tumor and tumor-infiltrating cells. Using a library of 34 peptides covering the entire ARG2 sequence, we examined reactivity toward these peptides in peripheral blood mononuclear cells from cancer patients and healthy individuals.

View Article and Find Full Text PDF

Background: The tryptophan-catabolizing enzyme indoleamine 2,3-dioxygenase 1 (IDO1), which subverts T-cell immunity at multiple levels, is itself subject to inherent T-cell reactivity. This intriguing deviation from central tolerance has been interpreted as counterbalancing IDO1-mediated immunosuppression. Based on this hypothesis, clinical studies employing an IDO1 peptide-based vaccine approach for cancer treatment have been initiated, but there remains a pressing need to further investigate the immunological ramifications of stimulating the anti-IDO1 T-cell response in this manner.

View Article and Find Full Text PDF

Historically, the development of cancer vaccines has focused on the central role of tumor antigens in eliciting tumor-specific immune responses, with limited success. Recent advances with checkpoint blockade approaches have brought about a renewed appreciation of the importance of targeting immune suppression in cancer patients. Here we discuss a novel approach to cancer immunotherapy, namely to target recently described T cells that uniquely control cells with immune suppressive functions.

View Article and Find Full Text PDF

Collaboration can be challenging; nevertheless, the emerging successes of large, multi-partner, multi-national cooperatives and research networks in the biomedical sector have sustained the appetite of academics and industry partners for developing and fostering new research consortia. This model has percolated down to national funding agencies across the globe, leading to funding for projects that aim to realise the true potential of genomic medicine in the 21st century and to reap the rewards of 'big data'. In this Perspectives article, the experiences of the RA-MAP consortium, a group of more than 140 individuals affiliated with 21 academic and industry organizations that are focused on making genomic medicine in rheumatoid arthritis a reality are described.

View Article and Find Full Text PDF

Dendritic cells (DCs), the most potent antigen-presenting cells of the immune system, express nuclear receptors for 1,25-dihydroxyvitamin D(3) (VD3) and they are one of its main targets. In the presence of VD3, DCs differentiate into a phenotype that resembles semimature DCs, with reduced T cell costimulatory molecules and hampered IL-12 production. These VD3-modulated DCs induce T cell tolerance in vitro using multiple mechanisms such as rendering T cells anergic, dampening of Th1 responses, and recruiting and differentiating regulatory T cells.

View Article and Find Full Text PDF

Dendritic cells (DCs) exposed to tumor antigens followed by treatment with T(h)1-polarizing differentiation signals have paved the way for the development of DC-based cancer vaccines. Critical parameters for assessment of the optimal functional state of DCs and prediction of the vaccine potency of activated DCs have in the past been based on measurements of differentiation surface markers like HLA-DR, CD80, CD83, CD86, and CCR7 and the level of secreted cytokines like interleukin-12p70. However, the level of these markers does not provide a complete picture of the DC phenotype and may be insufficient for prediction of clinical outcome for DC-based therapy.

View Article and Find Full Text PDF
Article Synopsis
  • Tumor antigens are crucial targets for cancer vaccines, and this study investigates their expression in esophagus carcinoma biopsies and a vaccine called MelCancerVac.
  • Treatment with the DNA methyltransferase inhibitor 5-aza-2'-deoxycytidine improved the expression of tumor antigen genes in vaccine-producing cells.
  • In esophageal squamous cell carcinoma, 81% of tumors expressed multiple cancer/testis antigens, while vaccine cells showed significantly higher expression of tumor antigens compared to normal tissues, with additional antigens induced after treatment.
View Article and Find Full Text PDF