Gene expression of T follicular helper (TFH) cells 6 h after ICOS-L blockade. Mus musculus

The maintenance of the TFH phenotype depends on continuous signals via ICOS. For a global assessment of differences in gene expression after interruption of the ICOS pathway a genome wide transcriptome analysis was performed. We used the OT-II adoptive transfer system to isolate antigen-specific TFH cells (day 6 after immunization) after short-term (6 hours) blockade of the ICOS pathway using a monoclonal antibody against ICOS-L. Overall design: Gene expression profiles of TFH cells with or without ICOS-L blockade. Affymetrix MG 430 2.0 whole genome arrays were performed in duplicates for the control and blockade group (4 arrays in total). To obtain genes significantly regulated upon ICOS L blockade, the expression profiles of TFH cells treated with an isotype control or anti-ICOS-L antibody were compared to each other. After total RNA extraction, reverse transcription, cDNA extraction, the biotinylated cRNA was transcribed, fragmented, and 15 µg cRNA hybridized in duplicates for each of the two groups to the 4 GeneChip arrays: Group1 TFH cells control, Group2 TFH cells ICOS-L blockade.