Quast, T. | Search bioRxiv

bioRxiv2022

GPR183 targets lung-resident CD301b+ conventional dendritic cells type 2 to a subtissular TSLP-TSLP receptor-mediated survival niche within the adventitial cuff

Conventional dendritic cells (cDCs) are strategically localized throughout non-lymphoid tissues. How such spatially regulated subtissular placement is achieved remains largely elusive. Here, we reveal that GPR183 targets CD301b+ cDC2 to a TSLP-dependent survival niche within the adventital cuff. We identified a close association of CD301b+ cDC2 with PDGFR+ fibroblasts within the adventitial region of the lung. Genetic ablation of GPR183 within the cDC lineage leads to a selective loss of CD301b+ cDC2 in conjunction with the loss of CD301b+ cDC2 : fibroblast colocalization. Next bone marrow chimeric experiments and expression studies suggested adventitial fibroblasts as the main source of 7,25 hydroxycholesterol, the natural ligand of GPR183. Single cell transcriptomic receptor ligand inference and subsequent genetic validation revealed TSLP receptor signalling as a crucial fibroblast derived CD301b+ cDC2 survival factor. These data expose a subtissular localization mechanism for tissue-specific functionalization of CD301b+ cDC2.

immunology↗

bioRxiv2017

Cellular reprogramming of human monocytes is regulated by time-dependent IL4 signalling and NCOR2

The clinical and therapeutic value of human in vitro generated monocyte-derived dendritic cell (moDC) and macrophages is well established. However, in line with recent findings regarding myeloid cell ontogeny and due to our limited understanding of their physiological counterparts, transcriptional regulation and heterogeneity, the full potential of these important cellular systems is still underestimated.\n\nIn this study, we use cutting edge high-dimensional analysis methods to better understand the transcriptional organization, phenotypic heterogeneity and functional differences between human ex vivo isolated and in vitro generated mononuclear phagocytes with the aim to better realize their full potential in the clinic.\n\nWe demonstrate that human monocytes activated by MCSF or GMCSF most closely resemble inflammatory macrophages identified in vivo, while IL4 signalling in the presence of GMCSF generates moDCs resembling inflammatory DCs in vivo, but not steady state cDC1 or cDC2. Moreover, these reprogramming regimes lead to activated monocytes that present with profoundly different transcriptomic, metabolic, phenotypic and functional profiles. Furthermore, we demonstrate that CD14+ monocytes are integrating multiple exogenous activation signals such as GMCSF and IL4 in a combinatorial and temporal fashion, resulting in a high-dimensional cellular continuum of reprogrammed monocytes dependent on the mode and timing of cytokine exposure. Utilizing nanostraw-based knockdown technology, we demonstrate that the IL4-dependent generation of moDCs relies on the induction, nuclear localization and function of the transcriptional regulator NCOR2.\n\nFinally, we unravel unappreciated heterogeneity within the clinically moDCs population and propose a novel high-dimensional phenotyping strategy to better tailor clinical quality control strategies for patient need and culture conditions to enhance therapeutic outcome.

immunology↗