FIG. 6.

Epithelial cells are a source of indoleamine-2,3-dioxygenase in susceptible mice and intelectin in resistant mice. Indoleamine-2,3-dioxygenase (A) and intelectin (B) expression in intestinal epithelial cells was measured by RT-PCR. Epithelial cells were isolated from the large intestine of naïve or T. muris-infected AKR and BALB/c mice, and total RNA was extracted. cDNA for HPRT was titrated out, and nonsaturated dilutions giving bands of equivalent brightness, shown as a single band per sample in the figure, were selected as the starting dilution for the serial dilutions. cDNA was serially diluted (1:2) and amplified by PCR as described in Materials and Methods. A, AKR; B, BALB/c. N, naïve; 21, day 21 postinfection.