We attempted to visualize and analyze in vivo therapeutic response of infliximab (IFX) in the murine IBD model using two photon laser scanning microscopy (TPLSM).
The number of leukocytes infiltrating to subserosa and muscular layer was reduced in IFX-treated mice, compared with non-IFX, control mice. The length of colonic crypt was increased in IFX-treated mice, compared with non-IFX, control mice. Serial change in regenerative epithelial cells was not observed, which regenerated from the bottom of the crypt toward the top of the crypt (the luminal side). The fluorescence labeled anti-TNF-alpha antibody was observed in the mucosal stroma, suggesting the binding of labeled antibodies with free TNF- alpha in the colonic tissue. It was also observed in the surface of leukocytes within the postcapillary venules or those infiltrating into the damaged crypt, suggesting the binding of labeled antibodies with the membrane binding TNF- alpha of the surface TNF- alpha producing cells.