Search bioRxiv⌕ Search

Biology subjects

Glasson, Y.

Publications and source records attributed to Glasson, Y..

3 recordsLinked to original sources

Deciphering the tumor-infiltrating CD73+ regulatory gammadelta T cell ecosystem associated with poor survival of patients with ovarian cancer

The ability of tumor cells to overcome immune surveillance is an essential step in tumor development and progression. Among the immune cells playing a role in tumor control, {gamma}{delta} T cells contribute to the immune response against many tumor types through their direct cytotoxic activity against cancer cells and their capacity to regulate the functions of other immune cells. However, their presence in the tumor microenvironment is also associated with poor prognosis, suggesting that {gamma}{delta} T cells may also have pro-tumor activities. We previously described a regulatory {gamma}{delta} T-cell subset that expresses CD73 and produces IL-10, IL-8 and adenosine. Here, we report a higher CD73+ {gamma}{delta} T cell density in the tumor microenvironment of ovarian cancer samples from patients with short-term than long-term survival. Starting from this original observation, we investigated their neighborhood and described a specific ecosystem according to their pro-tumor functions.

cancer biology↗

Spatial mapping of rheumatoid arthritis synovial niches reveals specific macrophage networks associated with response to therapy

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease affecting peripheral joints and for which approximately 40% of the patients respond insufficiently to the available synthetic or biologic disease modifying anti-rheumatic drugs (DMARDs). The infiltration of the synovial membrane by lymphocytes and monocytes profoundly alters its homeostatic functions, leading to chronic joint inflammation and bone destruction. A better understanding of how DMARDs impact the complex synovial cell social network in relationship to response/ non-response remains an unmet need to design more targeted and active therapeutic strategies. Here, we used imaging mass cytometry (IMC) to comparatively profile more than 115,000 cells in the synovial tissue of healthy, low inflammatory osteoarthritis and matched active early treatment-naive RA patients at baseline and at 6 months after starting DMARDs treatment. We notably highlighted that tissue resident macrophages (LYVE1+CD206+) in perivascular synovial niches encompassing specific subsets of vascular cells, fibroblasts and immune cells vanished in active RA but were recovered in response to DMARDs treatment. Combined ligand-receptor analysis of single-cell RNA sequencing datasets identified that IL10, C-type lectin or TAM (TYRO3, AXL and MERTK) receptors were particularly involved in the restoration of these spatial cell interactions in the context of clinical remission. In addition to providing an unprecedented synovial spatial mapping, our work uncovered novel potential cellular and molecular targets for the development of therapies for RA. One Sentence SummarySingle-cell spatial profiling of rheumatoid arthritis synovium identifies specific cell states linked to treatment response

immunology↗

In Lyl1-/- mice, adipose stem cell vascular niche impairment leads to premature development of fat tissues

Lymphoblastic leukemia-derived sequence 1 (Lyl1) encodes a hematopoietic- and endothelial-specific transcriptional factor. Lyl1-deficient mice are viable, but they display mild hematopoietic and vascular defects. Here, we report that young Lyl1-/- mice exhibit transient obesity associated with general expansion of adipose tissues and unrelated to food intake. The increased fat tissue development in Lyl1-/- mice resulted from an earlier adipocyte differentiation of adipose stem cells (ASCs) through non-cell autonomous mechanisms. Specifically, we found that in Lyl1-/- mice, the vascular structures of adipose tissues are unstable, more prone to angiogenesis and, consequently, cannot maintain adipose progenitors in the niche vessel wall. Together, our data show that in Lyl1-/- mice, the impaired vascular compartment of the adipose niche promotes uncontrolled ASC activation and differentiation, leading to early adipocyte expansion and premature depletion of ASCs. Our study highlights the major structural role of the adipose tissue vascular niche in coordinating stem cell self-renewal and differentiation into adipocytes.

physiology↗