Immunohistochemistry analysis of TFR-2 and TFR-1 molecules in small intestine.

Immunoperoxidase staining of the TFR-2 protein shows that the signal is widely distributed along the crypt/villus axis (A; original magnification, × 10), with some cells intensely stained in the crypts (B; original magnification, × 40), whereas the villus is homogeneously stained (C; original magnification, × 40). The reactivity is mostly cytoplasmic, without nuclear staining (B,C). Some lamina propria leukocytes are stained (B,E, arrows). TFR-1 protein is detectable in the crypts and villi, with diffuse intracellular and basolateral membrane-associated localizations (D, original magnification, × 10; and E, original magnification, × 40). Representative pictures from 3 different specimens are shown. TFR-2 protein was stained using G/14C2 mAb.