Expression of SH2D2A in T-cells is regulated both at the transcriptional and translational level

The T-cell specific adapter protein (TSAd) encoded by the SH2D2A gene is up-regulated in activated human CD4+ T-cells in a cAMP-dependent manner. Expression of SH2D2A is important for proper activation of T-cells. Here, we show that SH2D2A expression is regulated both at the transcriptional and translational level. cAMP signaling alone induces TSAd-mRNA expression but fails to induce increased TSAd protein levels. By contrast, TCR engagement provides signals for both TSAd transcription and translation. We further show that cAMP signaling can prime T-cells for a more prompt expression of TSAd protein upon TCR stimulation. Our study thus points to a novel mechanism for how cAMP signaling may modulate T-cell activation through transcriptional priming of resting cells.