Project description:The activation of thymic B cells is critical for their licensing as antigen presenting cells and resulting ability to mediate central tolerance. The processes leading to licensing are still not fully understood. By comparing thymic B cells to activated Peyer’s Patch B cells at steady state, we found that thymic B cell activation starts during the neonatal period and is characterized by TCR/CD40 dependent activation, followed by immunoglobulin class switch recombination (CSR) without forming germinal centers. Transcriptional analysis also demonstrated a strong interferon signature, which was not apparent in the periphery. Thymic B cell activation and CSR were primarily dependent on type III IFN signaling, and loss of type III IFN receptor in thymic B cells resulted in reduced thymocyte regulatory T cell (Treg) development. Finally, from TCR deep sequencing, we estimate that licensed B cells induce development of a substantial fraction of the Treg cell repertoire. Together, these findings reveal the importance of steady state type III IFN in generating licensed thymic B cells that generate T cell tolerance to activated B cells
Project description:Transcriptional profiles of four different myeloid antigen presenting cell (APC) subsets (BDCA-1+ circulating myeloid dendritic cells, CD14+ monocytes, and in vitro generated immature and mature monocyte-derived dendritic cells) were used for comprehensive transcriptome analysis. Based on the gene expression profiling data, a quantitative relationship between myeloid APC in functionally related gene spaces was established. Keywords = myeloid antigen presenting cells Keywords = dendritic cell subsets Keywords: repeat sample
Project description: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:Antigen presenting cells (APC) act as an integration point where signaling and metabolic pathways collaboratively determine cellular activation state and shape T cell responses. We performed a series of genome-wide knockout screens in interferon gamma (IFNg)-stimulated macrophages, identifying overlapping sets of regulators that control the expression of the T cell stimulatory or inhibitory proteins, MHCII, CD40, and PD-L1. This multi-screen approach defined novel pathways that differentially control these functionally-distinct proteins, and identified mitochondrial function as a global regulator of the IFNg response. Specifically, we report that complex I of the mitochondrial respiratory chain is necessary for signal transduction via the IFNgreceptor, and consequently for both macrophages and dendritic cells to function as APCs. The importance of mitochondrial function for the IFNg response contrasts with the known glycolytic dependency of pattern-recognition receptor stimulation, implicating metabolic state as a fulcrum of innate immunity.
Project description:Dr. van Kooyk's laboratory is exploring the function of antigen presenting cells, such as dendritic cells (DC), that regulate viral-antigen recognition, DC trafficking and T cell binding--all processes that initiate immunity or tolerance. Essential in this is the recognition of ligands by C-type lectins and the functional consequences of differential terminal glycosylation that may regulate DC function. In this study, the gene expression profile of glycosylation-related genes is examined in relation to the maturation of human antigen-presenting cells. Two pooled RNA samples, one each from immature and mature human monocyte-derived dendritic cells, were prepared and sent to Microarray Core (E). The RNA was amplified, labeled, and hybridized to the GLYCOv3 microarrays.
Project description:Lung antigen presenting cells isolated from wild type but not Spp1-/- mice induce Th1 and Th17 cells differentiation. The goal of this study is to identify the genes differentially expressed by lung antigen presenting cells from cigarette smoke exposed mice. These genes may play crucial roles in directing Th1 and Th17 cells differentiation. Lung antigen presenting cells were isolated from lungs of two groups of wild type and Spp1-/- mice that have been exposed to cigarette smoke for 4 months. Total mRNA was extracted from these samples.
Project description:The goal of this study is to compare tumor-infiltrating antigen presenting cell populations by global transcriptome profiling (RNA-seq) to help further delineate sub-populations of infiltrating myeloid cells in tumor. Methods: Four tumor antigen presenting cell populations were sorted from digested B78chOVA (melanoma variant) tumors in biological triplicate Results: RNA was extracted from the 4 groups (n=3 per group) and prepared for RNAseq. Sequencing yielded ~405 million reads with an average read depth of 33.7 million reads/sample. Reads were then aligned to the mouse genome (UCSC mm10) and those that mapped uniquely to known mRNAs were used to assess differential expression.
Project description:P25 is the major T cell epitope for Ag85B and enables them to induce P25-specific CD4+ Th1 cells. We used microarrays to examine the gene expression of antigen-presenting cells (APCs) stimulated with P25 and P25-specific CD4+ T cells.