Project description:The human gut includes plasma cells (PCs) expressing immunoglobulin A1 (IgA1) or IgA2, two structurally distinct IgA subclasses with elusive regulation, function and reactivity. We show here that intestinal IgA1+ and IgA2+ PCs co-emerged early in life, comparably accumulated somatic mutations, and were enriched within short-lived CD19+ and long-lived CD19− PC subsets, respectively. IgA2+ PCs were often clonally related to IgA1+ PCs and a subset of them presumably emerged from IgA1+ precursors. Of note, secretory IgA1 (SIgA1) and SIgA2 dually coated a large fraction of mucus-embedded bacteria, including Akkermansia muciniphila. Disruption of homeostasis by inflammatory bowel disease (IBD) increased newly formed and actively proliferating IgA1+ plasmablasts, depleted long-lived IgA2+ PCs, and increased SIgA1+SIgA2+ gut microbiota. Such increase featured enhanced IgA1 reactivity to pathobionts, including Escherichia coli, combined with depletion of beneficial Akkermansia muciniphila. Thus, gut IgA1 and IgA2 emerge from clonally related PCs and show unique changes of both frequency and reactivity in IBD.
Project description:To compare gene expression between CD11b+ IgA and CD11b- IgA cells in the small intestine, each cell population was isolated from the murine small intestine. Similar experiment with different sample was performed as described in Gene expression on CD11b+ IgA and CD11b- IgA cells in the small intestine #02
Project description:Krüppel-like factor 2 (KLF2) is a potent regulator of lymphocyte differentiation, activation and migration. However, its functional role in adaptive and humoral immunity remains elusive. Therefore, by using mice with a B cell-specific deletion of KLF2, we investigated plasma cell differentiation and antibody responses. We revealed that the deletion of KLF2 resulted in perturbed IgA plasma cell compartmentalization, characterized by the absence of IgA plasma cells in the bone marrow, their reductions in the spleen, the blood and the lamina propria of the colon and the small intestine, concomitant with their accumulation and retention in mesenteric lymph nodes and Peyer’s patches. Most intriguingly, secretory IgA in the intestinal lumen was almost absent, dimeric serum IgA was drastically reduced and antigen-specific IgA responses to soluble Salmonella flagellin were blunted in KLF2-deficient mice. Perturbance of IgA plasma cell localization was caused by deregulation of CCR9, Integrin chains αM, α4, β7, and sphingosine-1-phosphate receptors. Hence, KLF2 not only orchestrates the localization of IgA plasma cells by fine-tuning chemokine receptors and adhesion molecules but also controls IgA responses to Salmonella flagellin.
Project description:In order to provide information on the peptide sequence of the IgA glycopeptides, a proteomics analysis was run on LC-MS/MS data of N-glycosidase F-digested IgA samples, in which the N-glycans had been released. The samples included IgA (isolated) from: 1) the saliva samples from two healthy donors, 2) a pooled-plasma standard from a minimum of 20 human donors (VisuCon-F Frozen Normal Control Plasma; Affinity Biologicals, Ancaster, Canada), 3) 10 μg of a human plasma-derived IgA standard (Lee Biosolutions, Maryland Heights, MO), and 4) a human colostrum-derived SIgA standard (Athens Research and Technology, Athens, GA).
Project description:To compare gene expression between CD11b+ IgA and CD11b- IgA cells in the small intestine, each cell population was isolated from the murine small intestine.
Project description:This study identifies immune transcript signatures that may predict IgAV nephritis in skin biopsies and distinguish IgA-IRGN from IgAN and IgAV in kidney biopsies
Project description:This SuperSeries is composed of the following subset Series: GSE35487: Expression data from human with IgA nephropathy (IgAN) [HG-U133A] GSE35488: Expression data from human with IgA nephropathy (IgAN) [HG-U133A_ENTREZG_10] Refer to individual Series