Figure 2.

Immunohistochemical staining for human Bcl-2 in thymi and spleens from Bcl-2 transgenic mice. Splenocytes that have a brown color (resulting from diaminobenzidine staining) are positive for human Bcl-2. Note the much greater staining in spleen vs. thymus in the Bcl-2 transgenic mice (Top vs. Middle). Although there was much less staining in thymi vs. spleens of Bcl-2 transgenics, the cells that were positive for Bcl-2 in thymi were resistant to sepsis-induced apoptosis. As is apparent in Bottom, none of the Bcl-2-positive cells in the septic thymus were apoptotic, i.e., none of the Bcl-2-positive cells had features of pyknosis or karyorrhexis (n = 10 thymi from septic Bcl-2-Ig transgenic mice)