Fig. 3

Mesothelin expression in normal mouse tissues and cell lines. a Cell lines and naive C57Bl/6 mouse tissues (including peritoneal membrane, pancreas and diaphragm) were harvested, prepared and assayed as described in Methods. Samples were subjected to denaturing electrophoresis on 8 % SDS-acrylamide gels. Immunoblots were probed with polyclonal affinity-purified rabbit anti-mouse mesothelin antibody and HRP-conjugated donkey anti-rabbit antibody. Arrows point to mesothelin protein bands b Mesothelin can be detected by unpurified rabbit anti mesothelin antisera in supernatants of Wt Panc02 cells, with increased levels in Panc02 cells containing retrovirus constructs (RV) over-expressing mesothelin (RV clone 4, RV clone10), compared to Panc02 containing empty vector (RV vector). Mesothelin can also be seen in HEK 293 cells transfected with a mesothelin expressing plasmid (293 Meso). c Mesothelin can be detected in supernatants (RVclone 4) using sera purified on peptide PPGKEPYKVDEDLIFYQN in the carboxy terminal half of the mesothelin protein. The purified antibody detects the 49 kDa form of mesothelin, but not the 34 kDa form