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Blank, C.

Publications and source records attributed to Blank, C..

4 recordsLinked to original sources

SIGLEC1 FACILITATES MACROPHAGE-CD8+ T CELL INTERACTIONS AND CORRELATES WITH CANCER IMMUNOTHERAPY RESPONSE

Antigen-presenting cell (APC) interactions with cytotoxic T cells are critical for anti-tumour immunity and response to immune checkpoint blockade (ICB), yet context-specific regulators in the tumour microenvironment remain not fully defined. Here we identify the lectin receptor SIGLEC1 as a key mediator of macrophage-T cell interactions in human melanoma. In a well-characterized patient cohort, SIGLEC1 was selectively upregulated in inflammatory macrophages physically associated with activated/exhausted CD8 T cells. Imaging and functional analyses revealed that SIGLEC1 accumulates at the macrophage-T cell interface and promotes cell clustering. SIGLEC1 ligands were enriched on activated T cells, and their blockade reduced cytotoxic cytokine production ex vivo. Single-cell (spatial) transcriptomics across independent ICB-treated melanoma cohorts showed that SIGLEC1 macrophages localize near CD8 T cells and are enriched in responders, where they also associate with T cells expressing activation/exhaustion markers. These findings define a SIGLEC1-dependent macrophage-T cell niche linked to effective immunotherapy.

immunology↗

CMAS dampens anti-tumor immunity and associates with response to neoadjuvant immunotherapy in melanoma

Identifying immune-regulatory pathways to predict response is crucial for the efficacy of immune checkpoint blockade (ICB) immunotherapies. Sialylation is upregulated in tumor cells and modulates immune responses in cancer, yet its impact on patient clinical outcome and the spatial organization of the tumor microenvironment remain unclear. Here, using publicly available single-cell RNA sequencing data we show that expression of the sialylation master regulator CMAS in melanoma cells correlates with poorer patient survival. Using a murine melanoma model, we demonstrate that Cmas deletion in tumor cells severely impaired tumor growth and improved anti-tumor lymphoid and myeloid cell responses, increasing tumor cell-intrinsic susceptibility to interferon-gamma-, CD4+ T cell-, and macrophage-mediated killing. Single-cell spatial transcriptomics on neoadjuvant ICB-treated melanoma patient tumor biopsies revealed that CMAS expression in tumor cells inversely correlated with tumor cell proximity to and activation status of T cells and macrophages. Furthermore, expression of CMAS in tumor cells was increased in patients who did not respond to immunotherapy, compared to responders. Overall, our work identifies CMAS as a key modulator of tumor-immune dynamics associated with survival and response to neoadjuvant ICB immunotherapy in melanoma patients.

cancer biology↗

Differential effects of PD-1 and CTLA-4 blockade on the melanoma-reactive CD8 T cell response

Immune checkpoint inhibitors targeting programmed cell death protein 1 (PD-1) and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) have revolutionized the treatment of melanoma patients. Based on early studies addressing the mechanism of action, it was assumed that PD-1 blockade mostly influences T cell responses at the tumor site. However, recent work has demonstrated that PD-1 blockade can influence the T cell compartment in peripheral. blood. If activation of circulating tumor-reactive T cells would form an important mechanism of action of PD-1 blockade, it may be predicted that such blockade would alter either the frequency and/or the breadth of the tumor-reactive CD8 T cell response. To address this question, we analyzed CD8 T cell responses towards 71 melanoma associated epitopes in peripheral blood of 24 melanoma patients. We show that both the frequency and the breadth of the melanoma-reactive CD8 T cell response in peripheral blood was unaltered upon PD-1 blockade. In contrast, a broadening of the melanoma-reactive CD8 T cell response was observed upon CTLA-4 blockade, in concordance with our prior data. On the basis of these results, we conclude that PD-1 and CTLA-4 blockade impact the tumor-reactive CD8 T cell response in a distinct manner. In addition, the data provide an argument in favor of the hypothesis that anti-PD-1 therapy may primarily act at the tumor site. One sentence summaryWe demonstrate that, contrary to CTLA-4 blockade, PD-1 blockade in melanoma patients does not lead to an increase in the breadth or magnitude of the melanoma-reactive CD8 T cell response in peripheral blood, thereby arguing for a dominant effect of PD-1 blockade at the tumor site.

immunology↗

Community-driven data analysis training for biology

The primary problem with the explosion of biomedical datasets is not the data itself, not computational resources, and not the required storage space, but the general lack of trained and skilled researchers to manipulate and analyze these data. Eliminating this problem requires development of comprehensive educational resources. Here we present a community-driven framework that enables modern, interactive teaching of data analytics in life sciences and facilitates the development of training materials. The key feature of our system is that it is not a static but a continuously improved collection of tutorials. By coupling tutorials with a web-based analysis framework, biomedical researchers can learn by performing computation themselves through a web-browser without the need to install software or search for example datasets. Our ultimate goal is to expand the breadth of training materials to include fundamental statistical and data science topics and to precipitate a complete re-engineering of undergraduate and graduate curricula in life sciences.

bioinformatics↗