BTLA and PD-1 signals attenuate TCR-mediated gene expression

T cell coinhibitory immune checkpoints, such as PD-1 or BTLA, are bona fide targets in cancer therapy. Here we used a human T cell reporter line to measure transcriptome changes mediated by PD-1 and BTLA induced signalling. TCR/CD3 stimulation resulted in the upregulation of a large number of genes but also repressed a similar number of transcripts. PD-1 and BTLA signals attenuated transcriptomics changes mediated by TCR/CD3 signalling: upregulated genes tended to be suppressed and the expression of a significant number of downregulated genes was higher when PD-1 or BTLA signalling took place. BTLA was a significantly stronger attenuator of TCR/CD3 induced transcriptome changes than PD-1. A strong overlap between genes that were regulated indicated quantitative rather than qualitative differences between these receptors. In line with their function as attenuator of TCR/CD3 mediated changes we found strongly regulated genes to be prime targets of PD-1 and BTLA signalling.