Project description:Immune responses against tumor cells depend on T lymphocyte attraction and activity within the tumor microenvironment. Specialized immune-interacting fibroblasts, commonly referred to as fibroblastic reticular cells (FRC), form specialized niches in secondary lymphoid organs, originate from embryonic progenitors and foster T cell activation. FRCs have also been detected in tertiary lymphoid structures (TLS) in tumors, differentiating from cancer associated fibroblasts. However, the identity and differentiation of niche-forming cells that foster intra-tumoral T cell activity have remained elusive. Here, we employed single cell RNA-sequencing of EYFP+ fibroblasts and GP33/34-Tetramer+CD8+ T cells from experimental murine lung cancer and cell fate-mapping analysis, which revealed the ability of FRC subsets in lung tumors to differentiate from progenitors situated in mural and adventitial sites. Ablation of FRC progenitors in Tumor T cell environments (TTEs) of murine lungs led to reduced anti-tumor T cell activity and loss of tumor control during experimental coronavirus vector-based immunotherapy. Collectively, our study defines lung cancer-associated FRC niches and key processes involved in stromal-T cell interaction that could pave the way for improved cancer immunotherapy.
Project description:B cell-interacting reticular cells (BRC) form transcriptionally and topologically stable immune-interacting microenvironments that direct efficient humoral immunity. While several immune niche factors have been elucidated, the cues sustaining BRC function and topology across activation states remain unclear. Here, we employed single cell RNA-sequencing of human lymph node stromal cells and immune cells to analyse local BRC-immune cell interactions and compare them across SLOs and species from additional datasets. Shared BRC subsets were imprinted by tissue-specific gene signatures, but also expressed functionally convergent niche factors that directed regionalized leukocyte composition. Local BRC-immune cell interactions sustained BRC subset identity via immune cell-provided maturation factors. Bidirectional signalling programs were independent of activation state and mirrored across murine and human tissues. Collectively, our data reveal a conserved set of feedforward BRC-immune cell circuits that sustain topologically-organized, functional niches across inflammatory states, lymphoid organs and species.
Project description:RNAseq of primary murine alveolar epithelial cells type II (AECII) and the murine lung cells MLE-15 in order to identify potential candidates of trypsin-like proteases capable to cleave the influenza surface glycoprotein hemaglutinine (HA). AECII cells do support the cleavage of HA while MLE-15 cells do not. In addition, leukocytes where sequenced as well.
Project description:B cell-interacting reticular cells (BRC) form transcriptionally and topologically stable immune-interacting microenvironments that direct efficient humoral immunity. While several immune niche factors have been elucidated, the cues sustaining BRC function and topology across activation states remain unclear. Here, we employed single cell RNA-sequencing of stromal cells and immune cells from murine lymph nodes, Peyer’spatches and spleens to analyse local BRC-immune cell interactions and compare them across SLOs and species. Shared BRC subsets were imprinted by tissue-specific gene signatures, but also expressed functionally convergent niche factors that directed regionalized leukocyte composition. Local BRC-immune cell interactions sustained BRC subset identity via immune cell-provided maturation factors. Bidirectional signalling programs were independent of activation state and mirrored across murine and human tissues. Collectively, our data reveal a conserved set of feedforward BRC-immune cell circuits that sustain topologically-organized, functional niches across inflammatory states, lymphoid organs and species.
Project description:Lung-resident and circulatory lymphoid, myeloid, and stromal cells, expressing various pattern recognition receptors (PRRs), detect pathogen and danger-associated molecular patterns (PAMPs/DAMPs), and defend against respiratory pathogens and injuries. Here, we report the early responses of murine lungs to nanoparticle-delivered PAMPs, specifically the RIG-I agonist poly-U/UC (PUUC), with or without the TLR4 agonist monophosphoryl lipid A (MPLA). Using cellular indexing of transcriptomes and epitopes by sequencing (CITE-seq), we characterized the responses at 4 and 24 hours after intranasal administration. Within 4 hours, ribosome-associated transcripts decreased in both stromal and immune cells, followed by widespread interferon-stimulated gene (ISG) expression. Using RNA velocity, we show that lung-neutrophils dynamically regulate the synthesis of cytokines like CXCL-10, IL-1α, and IL-1β. Co-delivery of MPLA and PUUC increased chemokine synthesis and upregulated antimicrobial binding proteins targeting iron, manganese, and zinc in many cell types, including fibroblasts, endothelial cells, and epithelial cells. Overall, our results elucidate the early PAMP-induced cellular responses in the lung and demonstrate that stimulation of the RIG-I pathway, with or without TLR4 agonists, induces a ubiquitous microbial defense state in lung stromal and immune cells. Nanoparticle-delivered combination PAMPs may have applications in intranasal antiviral and antimicrobial therapies and prophylaxis.