Figure 1
Amebic colitis in CBA mice is associated with upregulation of Th2 and Th17 cytokines at the site of infection. Male CBA mice were intracecally inoculated with E. histolytica trophozoites and killed at 3, 14, and 35 days post-challenge for evaluation of infection by (a, top) culture of cecal contents and (a, bottom) cecal inflammation. Total RNA was extracted from ceca of infected CBA mice or age-matched naive controls and cytokine mRNA levels assessed by quantitative reverse transcription PCR. Infected ceca revealed a rapid and sustained upregulation of Th2 cytokines and IL-17A (b and c, respectively, P<0.05 at all time points vs. naive). The expression of (c) IL-23p19 was modestly elevated. (d) Arginase-1 was upregulated vs. iNOS during the course of infection and increased with duration. In contrast, (e) the expression of Th1 cytokines was suppressed to subnaive levels by day 14 (at day 3, IL-12p35 mRNA was statistically higher than naive mice). (f) There was no remarkable change in expression of IL-10 during the course of infection. (g) There was a static 10-fold increase in TNF-α expression during the course of infection. n=8 (day 3), 8 (day 14), 10 (day 35), and 5 (naive control). All values are expressed as mean±s.e.m. ratio to the average level of naive controls. *P<0.05, **P<0.01 compared to the cytokine's ratio at day 3.
