MPS vaccination alters long-term gene expression of antigen-presenting cells in lymph nodes
Ontology highlight
ABSTRACT: Given the importance of sustained antigen presentation in maintenance of lymph node (LN) immune responses, we hypothesized that vaccine antigen availability and antigen-presenting cell (APC) populations may affect LN expansion. Compared to LNs of mice given the full MPS vaccine, LNs of mice given an MPS vaccine without antigen became prominently less enlarged and contracted sooner.To identify potential mediators of this differential, antigen-dependent response, we next focused the analysis of our scRNA-seq dataset on LN APC populations.
Project description:Lymphoma growth is facilitated by the well-balanced infrastructure of the microenvironment in lymph nodes (LN). LNs undergo rapid expansion during lymphoma progression, often accompanied by excessive blood vessel growth. Here we report that aggressive lymphoma cause severe high endothelial venule (HEV) regression which impairs lymphocyte recirculation. In this study, we used transferred (i.v.) Eµ-Myc tumor cells as a mouse model of aggressive lymphoma. Blood endothelial cells from tumor bearing and control LNs were isolated by FACS and processed for single-cell RNA sequencing. The results revealed a detrimental mechanisms causing HEV-dedifferentiation during lymphoma growth with potential implications on tumor-targeting immune surveillance and strategies of immune therapy in LNs
Project description:Microparticles (MP) are small membranous particles (100-1000 nm) released under normal steady-state conditions and are thought to provide a communication network between host cells. Previous studies demonstrated that Mycobacterium tuberculosis (M.tb) infection of macrophages increased the release of MPs, and these MPs induced a proinflammatory response from uninfected macrophages in vitro and in vivo following their transfer into uninfected mice. To determine how M.tb infection modulates the protein composition of the MPs, and if this contributes to their proinflammatory properties, we compared the proteomes of MPs derived from M.tb-infected (TBinf-MP) and uninfected human THP-1 monocytic cells. MP proteins were analysed by GeLC-MS/MS with spectral counting revealing 68 proteins with statistically significant differential abundances. The 42 proteins increased in abundance in TBinf-MPs included proteins associated with immune function (7), lysosomal/endosomal maturation (4), vesicular formation (12), nucleosome proteins (4) and antigen processing (9). Prominent among these were the type I interferon inducible proteins, ISG15, IFIT1, IFIT2, and IFIT3. Exposure of uninfected THP-1 cells to TBinf-MPs induced increased gene expression of isg15, ifit1, ifit2, and ifit3 and the release of proinflammatory cytokines. These proteins may regulate the proinflammatory potential of the MPs and provide candidate biomarkers for M.tb infection.
Project description:mRNA vaccines are emerging as a powerful vaccine platform as they are well-tolerated and scalable. Modified non-replicating mRNA encoding Influenza hemagglutinin and encapsulated in lipid nanoparticles (LNP) induced robust antibody and CD4 T cell responses after intramuscular or intradermal delivery in rhesus macaques. We investigated the local innate immune responses modulating such vaccine-induced immunity at the sites of immunization (skeletal muscle and skin) and their draining lymph nodes (LNs). Rapid mobilization of antigen presenting cells was found at the LNP/mRNA-injection sites and LNs. Dendritic cells efficiently internalized the LNPs, translated the mRNA cargo and upregulated co-stimulatory molecules. In addition, several type I interferon-inducible genes were expressed at the immunization sites and draining LNs. The innate immune activation was transient and resulted in priming of antigen-specific CD4+ T cells exclusively in the vaccine-draining LNs. Collectively, mRNA-based vaccines induce type I interferon-polarized innate immunity and antigen production by antigen presenting cells, which resulted potent vaccine-specific responses.
Project description:Gene expression and T cell receptor profiles from single cells from populations of T cells stimulated with islet autoantigenic peptides. CD4 T cells were stimulated with native (proinsulin, GAD fragments) or neo-antigen epitopes or flu vaccine (Pediacel). Activated cells (identified as CD19- CD3+ CD4+,CD45-RO+ CD95+, CD154+CD69+ CD27+) were FACS-sorted, barcodes for samples were introduced with cell hashing as follows: patient, 1 pool 1 (Hashtag 1); patient 1 pool 2 (Hashtag 2) patient 2 pool 1 (Hashtag 3); patient 2 pool 2 (Hashtag 4) and Pediacel (patient 1 and 2; Hashtag 5). Hashtag info in ADT files, TCR sequences provided in VDJ files.
Project description:Antigen presenting dendritic cells (DCs) and monocytes capture and transport antigens from barrier tissues for presentation to antigen-specific T cells in the draining-lymph nodes (LNs). While DCs enter LNs through afferent lymphatics in a CCR7-dependent manner, how exactly antigen-carrying monocytes reach LNs is less clear since monocytes do not express CCR7 and can also enter LNs via the bloodstream. In steady state, and following injection of several PAMPs, scRNA-seq data on LN mononuclear phagocytes identified LN resident versus migratory type 1 and type 2 conventional (c)DCs despite downregulation of DC subset-defining transcripts, such as Xcr1, Clec9a, H2-Ab1, Sirpa, and Clec10a on migratory cDCs. Migratory cDCs gained expression of transcripts controlling cellular migration such as Ccr7, Ccl17, Ccl22, and Ccl5, while migratory monocytes expressed Ccr5 without Ccr7. Using two tracking methods and a gating strategy that clearly distinguishes migratory CD88hiCD26lo monocytes from CD88-CD26hi cDCs, we found that both captured antigens in the lung and migrated to lung-draining LNs. Using global and mixed-chimeric Ccl5-, Ccr2-, Ccr5-, Ccr7-, and Batf3-deficient mice, we found that CCR5+ monocytes follow CCL5-secreting migratory cDCs to reach the draining LN via lymphatic vessels. In a model of asthma, such recruited monocytes regulated the induction of type 2 immunity. Overall, our data suggest that CCL5-secreting migratory cDCs lay down the chemokine trail for CCR5+ antigen-presenting monocytes to reach draining lymph nodes and regulate adaptive immunity.
Project description:Lymph node (LN) stromal cells provide survival signals and adhesive substrata to lymphocytes. During an immune response, B cell follicles enlarge, questioning how LN stromal cells manage these cellular demands. Herein, we used a murine fate mapping system to describe a new stromal cell type that resides in the T cell zone of resting LNs. We used microarrays to detail the global programme of gene expression characterizing this new population of lymphoid stromal cells. Mice lymph nodes were collected and digested before cell sorting and RNA extraction and hybridization on Affymetrix microarrays. We sought to obtain homogeneous populations of lymphoid stromal cells in order to increase expression profiles.
Project description:Lymph nodes are secondary lymphoid tissues that play a critical role in filtering the lymph and supporting adaptive immune responses. Surgical resection of LNs, radiation therapy or infections may damage lymphatic vasculature and compromised immune functions. Here, we describe the generation of functional synthetic lympho-organoids (LOs) using LN stromal progenitors and decellularized extra cellular matrix-based scaffolds. We show that upon transplantation at the site of resected LNs, LOs become integrated into the endogenous lymphatic vasculature and efficiently restore lymphatic drainage and perfusion. Upon immunization, LOs support the activation of antigen-specific immune responses, thus acquiring properties of native lymphoid tissues. These findings provide the first proof-of-concept for the development of synthetic lympho-organoids suitable to restore lymphatic and immune cell functions.
Project description:To test the mechanism by which IGF1 is cardioprotective, we performed single cell RNA sequencing on myeloid cells isolated from the heart 3 days after myocardial infarction of mice with and without IGF1 treatment. Myocardial infarction was induced in C57Bl6/J mice by 45 min occlusion of the left anterior descending artery followed by 3 days of reperfusion. Animals of the IGF1 group (n=3) received 40 ng/g mature recombinant IGF1 subcutaneously as bolus at the beginning of reperfusion. In addition, IGF1 (1 µg/g/d) was administered continuously during reperfusion using micro-osmotic pumps (Alzet, 1003D) that were implanted subcutaneously. Control mice received vehicle (0.1% BSA). After 3 days hearts were digested and CD45+CD11b+ cells were isolated using FACS cell sorting. Each sample contained cells containing 1 control and 1 IGF1 treated mouse, labeled with TotalSeq hashtags. 16000 cells were used as input for the single-cell droplet libraries generation for each sample.
Project description:The mononuclear phagocyte (MP) system consists of macrophages, monocytes, and dendritic cells. MP subtypes play distinct functional roles in steady-state and inflammatory conditions. Though murine MPs are well characterized, their human homologues remain poorly understood, particularly in the lung and draining lymph nodes (LNs). Understanding these homologies, and their similarities and differences with murine MPs, is critical for identifying human genetic targets and thus developing human immunotherapies. To address this gap, we performed transcriptome-based alignment across fifteen distinct human and nine distinct murine lung and LN MPs. As controls to validate the analytical quality of cross-species pulmonary MP analysis, human blood and murine spleen MPs were used. Constrained canonical correlation, t-SNE and catplot visualization was used to align human and mouse MPs and identify MP subtypes with maximal correspondence across species. Among the top marker genes expressed in corresponding human-mouse MP pairs, only 30-10% of the genes overlapped, indicating a need for caution when identifying human gene variants and functions from mice. For instance, SPP1 is highly expressed in human interstitial macrophages but not alveolar macrophages (AMs), whereas in mice SSP1 is only expressed in AMs. Moreover, human LN dendritic cells (DCs) align best with murine LN DCs but not murine splenic DCs indicating cross-species similarity in tissue. Lastly, in both species, CD88 was the most useful cell surface marker for distinguishing monocyte/macrophages from DCs. Overall, these data provide a reference for analyzing cross-species transcriptome data and evaluating whether specific murine genes are suitable guides to identify the functionality of human MPs, or conversely, whether pursuing specific human genes in mice, is likely to be a valid and fruitful approach.
Project description:Langerhans cells (LC) in skin help initiate the immune response to locally presented antigens. We performed high-resolution single-cell RNA-sequencing (scRNAseq) analysis for antigen presenting cells including LC in normal mouse skin, and in mouse skin expressing the human papillomavirus (HPV) 16 E7 oncogene. Ear skin was collected from normal and trangenic mice. Dissociated CD45+ cells were processed for scRNA-seq using the 10X Genomics Chromium 3' gene expression kit (v2).