Defining the effects of prematurity on the lymphocyte transcriptome

Methods Peripheral blood samples were collected from premature infants at the time of hospital discharge at multiple sites and shipped to a central laboratory. Freshly purified PBMCs were isolated by Ficoll gradient centrifugation, sorted into individual lymphocyte cell types, and processed for total RNA. RNA isolated from CD8 lymphocytes (n=79) was used for RNA-Seq analysis using the Illumina HiSeq2500. Sequences were aligned using the SHRiMP algorithm and expression values were summarized using HTSeq. Normalized gene expression data were analyzed for significant changes in expression using various statistical approaches. Ingenuity Pathway Analysis software was used for gene set interpretation.