Figure 9.

Aminopeptidase N (PepN) treatment significantly impairs many but not all molecules in the TCR signaling pathway. For analysis of TCR signaling, NP-specific cytotoxic T lymphocyte (CTL) were stimulated for 15 min with phorbol 12-myristate 13-acetate (PMA) + ionomycin (IONO) in the presence or absence of PepN followed by staining with anti-CD8 and antibody for the indicated signaling molecule. Representative histograms showing levels of phosphorylated ERK, p38, and Jun N-terminal kinase (JNK) are presented in (A). The mean MFI ± SEM are shown for the level of phospho-ERK (B), phospho-p38 (C), phospho-JNK (D), and total ERK protein (E). Representative histograms (F) and mean MFI ± SEM (G) showing levels of phosphorylated mammalian target of rapamycin (mTOR). For the analysis of STAT1 activation, NP-specific CTL were stimulated for 15 min with type 1 IFN followed by staining with anti-phospho STAT1 antibody. Representative histograms are shown in (H) and mean MFI ± SEM in (I). All data are from three to four independent experiments. *p < 0.05, **p < 0.01, and ***p < 0.001.