Biology subjects

Dieu-Nosjean, M.-C.

Publications and source records attributed to Dieu-Nosjean, M.-C..

3 recordsLinked to original sources

bioRxiv2024

Clearing method adapted to FFPE tissues for 3D imaging of nerve fibers, B cells, and tertiary lymphoid structures

Biomedical samples are commonly used for histological examination after their inclusion in paraffin (Formalin-Fixed Paraffin-Embedded (FFPE) biopsy). However, they provide minimal information about the interactions between different tissue components such as blood vessels, nerves, and cellular aggregates. Here we present a modified iDISCO tissue-clearing method that we term miDISCO+. miDISCO+ can be used for analyzing FFPE samples, requires the use of only one single FFPE sample, and allows to acquire a detailed image of the 3D tissue/organ architecture and the relevant cellular interactions. The addition of an antigen retrieval step to the protocol enables to use antibodies whose binding is sensitive to formalin fixation due to antigen masking. This method enabled us to detect CD20+ B cell follicles and to show that they are in close contact with TH+ sympathetic nerve fibers in FFPE biopsies of human palatine tonsils, and to detect CD20+ B cells in lung tumors and observe their 3D organization within tertiary lymphoid structures. Thus, miDISCO+ could be a potent tool for clinicians to refine diagnosis and to select optimal personalized treatment by giving an integrated 3D view of the tissue structures and cellular interactions in single FFPE samples.

immunology↗

bioRxiv2023

Enkephalin-mediated modulation of basal somatic sensitivity by regulatory T cells in mice

CD4+CD25+Foxp3+ regulatory T cells (Treg) have been implicated in pain modulation in various inflammatory conditions. However, whether Treg cells hamper pain at steady state and by which mechanism is still unclear. From a meta-analysis of the transcriptomes of murine Treg and conventional T cells (Tconv), we observe that the proenkephalin gene (Penk), encoding the precursor of analgesic opioid peptides, ranks among the top 25 genes most enriched in Treg cells. We then present various evidence suggesting that Penk is regulated in part by members of the TNF receptor family and the transcription factor Batf. Using mice in which the promoter activity of Penk can be tracked with a fluorescent reporter, we also show that Penk expression is mostly detected in Treg and activated Tconv in non-inflammatory conditions in the colon and skin. Functionally, Treg cells proficient or deficient for Penk suppress equally well the proliferation of effector T cells in vitro and autoimmune colitis in vivo. In contrast, inducible ablation of Penk in Treg leads to heat hyperalgesia in both male and female mice. Overall, our results indicate that Treg might play a key role at modulating basal somatic sensitivity in mice through the production of analgesic opioid peptides.

immunology↗

bioRxiv2023

Tertiary lymphoid structures are associated with enhanced macrophage and dendritic cell activation and proximity to CD8+ T cells, which better predict the clinical outcome of cervical cancer patients

BackgroundCervical tumors are usually treated using surgery, chemotherapy, and radiotherapy, and would benefit from immunotherapies. However, the immune microenvironment in cervical cancer remains poorly described. Tertiary lymphoid structures (TLS) were recently described as markers for better immunotherapy response and overall better prognosis in cancer patients. MethodsWe integratedly evaluated the cervical tumor immune microenvironment, and specifically TLS importance, using combined high-throughput phenotyping, soluble factor dosage, spatial interaction analyses, and statistical analyses. ResultsWe demonstrate that TLS presence is associated with a more inflammatory soluble microenvironment, with the presence of B cells as well as more activated macrophages and dendritic cells (DCs). Furthermore, this myeloid cell activation is associated with expression of immune checkpoints, such as PD-L1 and CD40, and close proximity of activated conventional DC2 to CD8+ T cells, therefore indicating better immune interactions and tumor control. Finally, we associate TLS presence, greater B cell density, and activated DC density to improved progression-free survival, and present it as an additional prognostic marker. ConclusionTo conclude, our results provide an exhaustive depiction of the cervical tumor immune microenvironment where TLS presence marks cell activation and immunotherapy target expression. These findings provide predictive clues for patient response to targeted immunotherapies. SignificanceTLS maturation stratifies cervical cancer patients and associates with improved prognosis. TLS associate with the expression of immune checkpoints, notably in the macrophage compartment, which may represent a new therapeutic strategy.

immunology↗