MicroRNAs (miRNAs) are important regulators of cell fate decisions in immune responses. They act by coordinate repression of multiple target genes, a property that we exploited to uncover regulatory networks that govern T helper-2 (Th2) cells. A functional screen of individual miRNAs in primary T cells uncovered multiple miRNAs that inhibited Th2 cell differentiation. Among these were miR-24 and miR-27, miRNAs coexpressed from two genomic clusters, which each functioned independently to limit interleukin-4 (IL-4) production. Mice lacking both clusters in T cells displayed increased Th2 cell responses and tissue pathology in a mouse model of asthma. Gene expression and pathway analyses placed miR-27 upstream of genes known to regulate Th2 cells. They also identified targets not previously associated with Th2 cell biology which regulated IL-4 production in unbiased functional testing. Thus, elucidating the biological function and target repertoire of miR-24 and miR-27 reveals regulators of Th2 cell biology. Overall design: Gene expression analysis of miRNA-deficient mouse CD4+ T cells transfected with miRNA mimics twice over a 5 day in vitro culture in the presence of low amounts of exogenous IL-4 (10U/ml). Cells transfected with either miR-23, miR-24 or miR-27 were compared to cells transfected with a control mimic. Data are from at least biologic triplicates.
MicroRNAs 24 and 27 Suppress Allergic Inflammation and Target a Network of Regulators of T Helper 2 Cell-Associated Cytokine Production.
Cell line, Subject
View SamplesBasophil functional state was determined using the Flow2CAST Basophil Activation Test (BAT). Human basophils were isolated from whole blood of three house dust mite (HDM) responsive donors with reactive basophils and two donors with anergic basophils. Basophil isolation was performed using the EasySep Human Basophil Enrichment kit (Stemcell). Purity of the basophils was determined by flow cytometry and ranged from 96 - 99%. For stimulation, 75,000 basophils were incubated for 4 hr with or without 50 ul of anti-FCERI antibody (Bhlmann Laboratories) in a total volume of 200 ul of Stimulation Buffer provided by the Flow2CAST kit. After incubation, the basophils were collected and re-suspended in TRIzol Reagent (Life Technologies). Total RNA was extracted using double extraction protocol using the guanidinium thiocyanate-phenol-chloroform extraction (Trizol Invitrogen), followed by a Qiagen RNeasy Micro clean-up procedure. cDNA and ST-ssDNA were prepared, fragmented and labeled according to Nugen WT Ovation Pico RNA Amplification and WT Ovation Exon kit and Encore Biotin protocols. The labeled ssDNA was hybridized on the Affymetrix Human GeneChip 1.0 ST Arrays, which subsequently were processed and stained using GeneChip Fluidics Station 450. The stained GeneChip Arrays were scanned in the Microarray Facility at the Biopolis Shared Facility using a GeneChip Scanner 3000. Quality control for the Arrays was performed using the Affymetrix Expression Console Software.
Systematic characterization of basophil anergy.
Specimen part, Subject
View Samples