Photomicrographs of intestine and spleen from CD3ε transgenic and STAT1-deficient mice treated for 72 hours with IL-18 plus IL-12.

In contrast to the lesions seen in C57BL/6 control mice and SCID mice (Figure 2A-C), the small intestinal villi of both CDεTG mice (A) and STAT1^−/− mice (C) are normal. The spleen from both the CD3εTG mice (B) and STAT1^−/− mice (D) show normal lymphoid tissue (white pulp and increased extramedullary hematopoiesis in the red pulp, arrows). H & E stain, 200 × (panels A and D) or 100 × (panels B and C) magnification.