Identification of novel regulators of Th2 cells in HDM model (RNA-Seq)

Naïve CD4 T cells differentiate into functionally diverse subsets of T helper (Th) cells. Gene expression profiling has the capacity to pinpoint factors that regulate subset differentiation and function, however obtaining transcriptional profiles of pure populations has been challenging. We performed single cell RNA-Sequencing (scRNA-Seq) of T helper cells from lymph node, lung and airways in a mouse model of asthma. scRNA-Seq resolved transcriptional profiles of naïve CD4 T, Th1, Th2, Treg cells and various activated states including a population responding to type I interferons. A trajectory for Th2 cell differentiation was delineated over time, with Th2 cells acquiring follicular T helper cell characteristics in the lung-draining lymph node before undergoing further modifications in the lung. A feature of airway Th2 cells was their enrichment for genes associated with lipid metabolism and experiments with blockers of key metabolic pathways supported roles for glucose and lipid metabolism in Th2 cell differentiation. Overall design: Mice were sentized and challanged with HDM extract intranasally. scRNA-Seq was performed in 384-well format. The relevant organs (either BAL, lung or mLN) were isolated, rapidly processed, stained for a panel of surface markers and single cell sorted within approximately 90 minutes of organ harvest. In total 764 memory T helper cells (CD3+CD4+CD44+) were sorted directly into lysis buffer using a BD Influx from two independent mice 15 days after sensitization and challenge with HDM as described above. In addition, 50 naïve T Helper cells (CD3+CD4+CD62LhiCD44lo), 50 Treg cells (CD3+CD4+CD25hi) from mLN of a mouse not exposed to HDM; 200 ST2+ mLN and 82 ST2+ lung T helper cells (CD3+CD4+CD44+ST2+CD25-) were sort purified at day 10 of the HDM model. SMART-Seq2 libraries were prepared using the method described in Picelli et al. (Nature Methods 2013) by the Eukaryotic Single Cell Genomics national facility at SciLife Laboratory, Stockholm.