Project description:Single-cell RNA-sequencing (scRNA-Seq) is widely used to characterize immune cell populations. However, mRNA levels correlate poorly with expression of surface proteins, which are well established to define immune cell types. CITE-Seq (cellular indexing of transcriptomes and epitopes by sequencing) utilizes oligonucleotide-tagged antibodies to simultaneously analyze surface phenotypes and transcriptomes. Considering the high costs of adding surface phenotyping to scRNA-Seq, we aimed to determine which of 188 tested CITE-Seq antibodies can detect their antigens on human peripheral blood mononuclear cells (PBMCs), a commonly interrogated cell population in immunology, and find the optimal concentration for staining. The recommended concentration was optimal for 76 antibodies, whereas staining quality of 7 antibodies improved when the concentration was doubled. 33 and 8 antibodies still worked well when the concentration was reduced to 1/5 or 1/25, respectively. 64 antigens were not detected at any antibody concentration. Optimizing the antibody panel by removing antibodies not able to detect their target antigens and adjusting concentrations of the remaining antibodies could enable a cost reduction of almost 50%. In conclusion, our data are a resource for building an informative and cost-effective panel of CITE-Seq antibodies and use them at their optimal concentrations in future CITE-seq experiments on human PBMCs.
Project description:Defining the immunological landscape of human tissue is an important area of research, but challenges include the impact of tissue disaggregation on cell phenotypes and the low abundance of immune cells in many tissues. Here, we describe methods to troubleshoot and standardize Cellular Indexing of Transcriptomes and Epitopes by sequencing (CITE-seq) for studies involving enzymatic digestion of human tissue. We tested epitope susceptibility of 92 antibodies commonly used to differentiate immune lineages and cell states on human peripheral blood mononuclear cells following treatment with an enzymatic digestion cocktail used to isolate islets. We observed CD4, CD8a, CD25, CD27, CD120b, CCR4, CCR6, and PD1 display significant sensitivity to enzymatic treatment, effects that often could not be overcome with alternate antibodies. Comparison of flow cytometry-based CITE-seq antibody titrations and sequencing data supports that for the majority of antibodies, flow cytometry accurately predicts optimal antibody concentrations for CITE-seq. Comparison by CITE-seq of immune cells in enzymatically digested islet tissue and donor- matched spleen not treated with enzymes revealed little digestion-induced epitope cleavage, suggesting increased sensitivity of CITEseq and/or that the islet structure may protect resident immune cells from enzymes. Within islets, CITEseq identified immune cells difficult to identify by transcriptional signatures alone, such as distinct tissue-resident T cell subsets, mast cells, and innate lymphoid cells (ILCs). Collectively this study identifies strategies for the rational design and testing of CITE-seq antibodies for single-cell studies of immune cells within islets and other tissues.
Project description:In order to test the transcriptome-wide functionality of the identified sRSE instances, we performed an in vivo titration experiment in which synthetic RNA oligonucleotides harboring tandem sRSE1 repeats were used as intracellular decoys that would bind the putative trans factor, preventing it from targeting endogenous transcripts. Capped and poly-adenylated RNAs carrying tandem sRSE elements were transfected along with scrambled RNA molecules as control. 48 hours post-transfection, samples were subjected to transcriptome profiling to measure the regulatory consequences of the in-vivo titration of the sRSE-binding trans factor.
Project description:This time course analysis is to study the targets and functions of miR-124. MiR-124 was overexpressed and the effect of miR-124 overexpression was compared to negative controls to identify downregulated genes and potential miRNA targets. Keywords: time course
Project description:This phase I trial studies how well an imaging agent called I-124 M5A works in detecting CEA-positive colorectal cancer that has spread to the liver. I-124 M5A is a monoclonal antibody, called M5A, linked to a radioactive substance called I-124. M5A binds to CEA-positive cancer cells and may, through imaging scans, be able to detect liver metastases by picking up signals from I-124.
Project description:Purpose: Analysis at the single cell level of the CD4+ and CD8+ Lymphocytes T extracted and PBMCs from healthy human donor Methods: Single Cell RNAseq performed using the 10X genomics platform