A. Colon samples were harvested on days +1, +3 and +6 post-BMT following lethal irradiation and BMT using the BALB/c to B6 strain combination. Protein was extracted and analyzed by western blotting for STAT1, p-STAT1 (Tyr701), STAT3 and pSTAT3 (Tyr705) expression. Data are representative of one out of two independent experiments.
B. Immunohistochemical analysis of STAT1 and p-STAT1 in colon tissues. 100x magnification of representative colon tissue from syngeneic controls or GVHD animals. Slides were stained with STAT1 and p-STAT1 specific antibodies. STAT1 and p-STAT1 expression are significantly increased in GVHD animals compared to syngeneic controls on day +6. This coincided with signs of tissue damage (crypt apoptosis and luminal sloughing).
C. Semiquantitative scoring of staining intensity of STAT1 and pSTAT1 in colon and small bowel samples. A total of four animals per group were studied.