The benefit of immune checkpoint blockade for cancer therapy is limited to subsets of patients because of factors including the accumulation of immunosuppressive metabolites, such as adenosine, within tumors. Pharmacological inhibition of adenosine generation and signaling is an active area of clinical investigation, but only limited clinical benefit has been reported. Here, we show that adenosine suppresses anti-cancer T cell responses following uptake into activated T cells by equilibrative nucleoside transporter 1 (ENT1) and inhibition of de novo pyrimidine nucleotide synthesis. We identify EOS301984 as a potent ENT1 antagonist that restores pyrimidine levels in activated T cells in adenosine-rich environments, resulting in enhanced tumor cell killing by memory T cells and increased ex vivo expansion of functional human tumor-infiltrating lymphocytes. A combination of EOS301984 with anti-PD-1 led to synergistic control of tumor growth in a humanized mouse model of triple-negative breast cancer. ENT1 inhibition, therefore, augments anti-cancer immune responses through the restoration of pyrimidine nucleotide synthesis in T cells suppressed by adenosine.
© 2025. The Author(s).

BRAF-mutated colorectal cancer correlates with poor prognosis and limited response to standard treatments. Combining immune checkpoint inhibitors with BRAF/MEK inhibitors shows promise against BRAF-mutant melanoma in both preclinical and clinical trials. Therefore, we hypothesized that the treatment would be effective against BRAF-mutant colorectal cancer. In this study, we assessed the efficacy of combining immune checkpoint inhibitors with BRAF and/or MEK inhibitors in BRAF-mutant colorectal cancers. We treated BRAF V600E colorectal cancer cells HT-29 and SNU-1235 with encorafenib (BRAF inhibitor) and binimetinib (MEK inhibitor) and assessed the degrees of MAPK inhibition, JAK/STAT inhibition, cell viability, apoptosis, and the expression of antigen presenting machinery. We also inoculated HT-29 cells into mice and treated them with an immune checkpoint inhibitor (durvalumab), encorafenib, and binimetinib for 4 weeks. We found that treatment with BRAF inhibitor, MEK inhibitor, or their combination led to significant tumor growth reduction, along with the MAPK and JAK/STAT pathway inhibition, antigen presenting machinery induction, and cytotoxic T cell activation. Our study demonstrates the potential effectiveness of combining immune checkpoint inhibitors with BRAF or MEK inhibitors for BRAF-mutated colorectal cancers.
© 2025. The Author(s).

The stability of immune responses to SARS-CoV-2 vaccines, especially concerning the cross-reactive recognition of the Omicron variant, remains incompletely characterized in multiple myeloma (MM) patients. This study evaluated humoral responses in 29 MM patients and cellular responses in a subset of 19 MM patients, specific to Wuhan and Omicron spike proteins, between 16 and 26 weeks following the third vaccine dose. After 26 weeks, we highlighted a significant reduction in the neutralizing antibodies to both spikes and the percentages of IFN-γ+CD107a+ spike-specific CD8+ T cells. On the other hand, patients who underwent an additional stimulation between the two time points, through either a fourth vaccine dose or breakthrough infection, showed a significant increase in neutralizing antibodies and stable levels of cytotoxic CD8+ T cells. Additionally, those with only three doses experienced a higher rate of breakthrough infections during the 32-week follow-up period. These findings underscore the waning of vaccine-induced immunity over time and may help benefit-risk evaluation in vaccination strategies in MM patients.
Copyright © 2025 Raimondi, Storti, Vescovini, Franceschi, Toscani, Notarfranchi, Dalla Palma, Iannozzi, Minesso, Scita, Lungu, Dessena, Donofrio and Giuliani.

The human dendritic cell (DC) family has recently been expanded by CD1c+CD14+CD163+ DCs, introduced as DC3s. DC3s are found in tumors and peripheral blood of cancer patients. Here, we report elevated frequencies of CD14+ cDC2s, which restore to normal frequencies after tumor resection, in non-small cell lung cancer patients. These CD14+ cDC2s phenotypically resemble DC3s and exhibit increased PD-L1, MERTK, IL-10, and IDO expression, consistent with inferior T cell activation ability compared with CD14- cDC2s. In melanoma patients undergoing CD1c+ DC vaccinations, increased CD1c+CD14+ DC frequencies correlate with reduced survival. We demonstrate conversion of CD5+/-CD1c+CD14- cDC2s to CD14+ cDC2s by tumor-associated factors, whereas monocytes failed to express CD1c under similar conditions. Targeted proteomics identified IL-6 and M-CSF as dominant drivers, and we show that IL-6R and CSF1R inhibition prevents tumor-induced CD14+ cDC2s. Together, this indicates cDC2s as direct pre-cursors of DC3-like CD1c+CD14+ DCs and provides insights into the importance and modulation of CD14+ DC3s in anti-tumor immune responses.
Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.

CD4+ T-helper 17 (Th17) T cells are a key population in protective immunity during infection and in self-tolerance/autoimmunity. Through the secretion of IL-17, Th17 cells act in promotion of inflammation and are thus a major potential therapeutic target in autoimmune disorders. Recent reports have brought to light that the IL-17 family cytokines, IL-17A, IL-17F and IL-17AF, can directly act on CD4+ T-cells, both in murine and human systems, inducing functional changes in these cells. Here we show that this action is preferentially targeted toward naïve, but not memory, CD4+ T-cells. Naïve cells showed transcriptome changes as early as 48 hours post-IL-17 exposure, whereas memory cells remained unaffected as late as 7 days. These functional differences occurred despite similar IL-17 receptor expression on these subsets and were maintained in co-culture/transwell systems, with each subset maintaining its functional response to IL-17. Importantly, there were differences in downstream transcriptional signaling by the three IL-17 cytokines, with the IL-17AF heterodimer conferring both the greatest transcriptional change and most altered functional consequences. Detailed transcriptome analysis provides important insights into the genes and pathways that are modulated as a result of IL-17-mediated signaling and may serve as targets of future therapies.
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