Distinct stimulatory signals promote the diversification of cDC1 functional states in tumors — ASN Events

Distinct stimulatory signals promote the diversification of cDC1 functional states in tumors (#249)

Nadine Nuschele 1 , Maria Parra Reyes 1 , Lukas Ramsauer 1 2 3 , Erik Müller 1 , Anna Hirschberger 1 , Jan P. Böttcher 1 2 3
  1. Institute of Molecular Immunology, School of Medicine and Health, Technical University of Munich (TUM), Munich, Bayern, Germany
  2. Department of Experimental Immunology, Institute of Immunology, University of Tübingen, Tübingen, Baden-Württemberg, Germany
  3. M3 Research Center, University Hospital Tübingen, University of Tübingen, Tübingen, Baden-Württemberg, Germany

Type 1 conventional dendritic cells (cDC1) are critical orchestrators of anticancer immunity by cytotoxic CD8+ T cells and their abundance within tumors is associated with cancer immune control. Recent studies suggest that following the acquisition of cancer cell antigens, cDC1 in tumors can acquire functionally distinct activation states that both contribute to the regulation of anticancer T cell responses. One state comprises migratory CCR7+ cDC1, capable of shuttling antigen to tumor-draining lymph nodes (tdLNs) for naive CD8+ T cell priming. A second state comprises immunostimulatory cDC1 that lack CCR7 expression, do not migrate to tdLNs and produce the chemokine CXCL9 within tumor tissue, facilitating the interplay with tumor-infiltrating, stem-like TCF1+CD8+ T cells. However, the molecular mechanisms promoting the development of these two different activated cDC1 states remains unclear.  By using in vitro culture systems with bona fide cDC1 generated from bone marrow cells, we have started investigating the capacity of different damage associated molecular patterns (DAMPs) and innate immune stimuli to induce the development of the distinct activated cDC1. Our data identify different classes of molecules that preferentially induce the differentiation of either CCR7neg or CCR7+ cDC1. Moreover, our data suggest that both activated cDC1 subpopulations can arise directly from immature cDC1 but not sequentially from each other. Collectively, our findings provide insights into molecular mechanisms that shape the functional diversification of activated cDC1 in tumors that may be targeted to influence the course of cDC1-mediated anticancer immunity.