Project description:Marginal zone (MZ) B cells bridge innate and adaptive immunity by sensing bloodborne antigens and producing rapid antibody and cytokine responses. When unregulated, MZ B cells are associated with autoimmunity. CD55 is a membrane-bound complement regulator that interferes with complement activation and is another important component of innate and adaptive immunity. MZ B cells express low CD55 in both mice and humans, but the role of CD55 in MZ B cell function is unknown. Using germline knockout mice, we found that similar numbers of MZ B cells were initially established in 3-week-old CD55-deficient mice compared to wild-type (WT) mice. However, MZ B cells failed to accumulate as mice aged and underwent increased apoptosis independent of alternative complement activation. Following ex vivo stimulation of MZ B cells through Toll-like receptor 9 (TLR9), we observed increased IL-6 expression in CD55 KO MZ B cells. In addition, CD55 KO mice exhibited reduced total IgG response with in vivo administration of TLR9 agonist. These findings provide new insights to the role of CD55 in MZ B cell survival and B cell function.
Project description:Lisbon lemon trees were grafted with budwood infected with the citrus greening bacterium, 'Candidatus Liberibacter asiaticus', or control budwood, and leaf samples were collected every two weeks post graft for LC/MS analysis. This project has shotgun proteomics data for leaf samples from 5 control and 5 CLas grafted trees at the 14 week post graft timepoint.
Project description:Mouse platelets were collected following 4 days of exercise or standard-housing from 8-week-old C57BL/6J mice and mass spectrometry performed (5 mice per group). The analysis revealed differences in the proteomic content of platelets isolated from standard-housed and exercising mice.
Project description:Purpose: Next-generation sequencing (NGS) has revolutionized systems-based analysis of cellular pathways. The goals of this study are to compare the genes expression difference at transcriptome level; Methods: Total RNA was extracted from whole cells with the mirVana miRNA Isolation Kit according to the manufacturer’s protocol. RNA quality and integrity were evaluated with an Agilent 2100 Bioanalyzer. Samples with an RNA integrity number (RIN) ≥ 7 were considered to be of high quality and were processed further and subjected to subsequent analysis. Total RNA-seq libraries were generated using 4 μg of total RNA, which was analyzed using the TruSeq Stranded mRNA LTSample Prep Kit. These libraries were then sequenced using the Illumina sequencing platform (HiSeqTM 2500 or Illumina HiSeq X Ten), and 125-bp/150-bp paired-end reads were generated. Results: The raw reads containing adaptors and the low-quality reads from the raw data were removed using Trimmomatic to obtain clean reads. Transcriptome sequencing was conducted by OE Biotech Co., Ltd. (Shanghai, China), and clean reads were provided. The clean reads were mapped to the hg38 reference genome using hisat2 (version 2.1.0). The output BAM files were converted to SAM files using SAMtools 1.9. The final TPM values were obtained using Stringtie 1.3.5. Conclusions: To understand the mechanistic basis of GPI biosynthesis upregulation by the CD55 precursor, we performed RNA- sequencing (RNA-seq) of samples of parental PIGS-HRD1-DKO, PIGS-HRD1-CD55-TKO, and PIGS-HRD1-CD55-TKO stably overexpressed HA-CD55 stably overexpressing cells. Total RNA was extracted and analyzed. The expression profile of GPI biosynthesis -related genes was not significantly affected by CD55.
Project description:(Submitter supplied) Identification of transcription factors (TFs) which upregulate human CD55 expression. CD55 was originally described as a cellular complement regulator that protects self-cells from autologous complement attack. It is now known as cellular regulator which controls many functions of cells, as examples T cell commitment to T effector cells vs Foxp3+ T regulatory cells, B2 cell Ab production, and receptor tyrosine kinase (RTK) growth factor receptor function. Overlap of the arrays identified the immunosuppressive TF Kruppel Like Factor 4 (KLF4). The current study shows that CD55 functions jointly with KLF4.
Project description:Complement overactivation, has been verified in COVID-19 patients. Complement regulatory proteins, including CD55, control complement overactivation thus eliminating complement deposition and cell lysis. We investigated complement regulatory protein expression in COVID-19 for potential deregulated expression patterns driving disease pathogenesis. Single-cell RNA-seq revealed increased PBMCs CD55 expression in severely and critically ill patients. This increase was also detected upon integrated subclustering analysis of monocyte, T cell and B cell populations. FACS analysis confirmed the significant upregulation of CD55 expression in CD4+ and CD8+ T cell and monocyte populations of severely and critically ill COVID-19 patients. This upregulation was associated with decreased expression of type-I IFN-stimulated genes (ISGs) in patients with severe and critical COVID-19, indicating a suppressor effect of CD55. Silencing of CD55 in T cells from COVID-19 severely ill patients in-vitro and sensitization with SARS-CoV-2 peptides resulted in significantly augmented expression of ISGs and a reversal of their expression to levels similar to control or higher. The present study uncovers, to the best of our knowledge, a novel regulatory effect of CD55 on type-I IFN responses of severely ill COVID-19 patients, thus indicating its contribution to COVID-19 pathogenesis, and identifies a novel mechanistic pathway in the COVID-19 immune response.