Figure 2.

SELENOI deficiency caused decreases in de novo PE and plasmenyl PE synthesis during T cell activation. (A) Flow cytometry analyses of size (forward scatter) vs granularity/size (side scatter) showed equivalent profiles of WT and SELENOI KO T cells. (B–C) An FITC-duramycin probe was used to measure PE levels in inactivated and activated T cells from WT and KO mice. FITC-BSA was used as a negative control probe. (D) Cy5-duramycin combined with CSFE was used to measure PE levels after three days of cell division. (E) T cells were pulsed with ¹³C₂-labeled ethanolamine during TCR activation (18 h) and LCMS was used to measure PE species calculated as pmol/10⁶ cells (see Figure S2) that were in turn used to calculate the levels of unlabeled and labeled PE. The levels of ¹³C₂-labeled PE represent de novo synthesis during the T cell activation period. (F) The same metabolically pulsed T cells were analyzed for the levels of unlabeled and labeled plasmenyl PE. Means of replicates (N = 3) were compared using Student's t test and expressed as mean ± SEM with ∗p < 0.05.