Abstract
Purpose:
Seasonal allergic conjunctivitis displays significant individual variation in humans due (at least in part) to differences in genetic background. As part of a program to optimize a murine model of the disease, we compared the responses of 6 strains of mice to a controlled allergen challenge in order to identify the most sensitive strain.
Methods:
Six strains of albino mice (B6 [Cg]-Tyrc-2J/J, SWR/J, B6 Albino [B6N-TyrC/BrdCrCrl], Swiss Webster [Crl:CFW(SW)], Balb/C [BALB/cAnNCrl], and CD1 [Crl:CD1(ICR)]) were examined in this study. On Day 0, all were sensitized subcutaneously in both hind hocks with 100µg of short ragweed (SRW) in 650µg of aluminum hydroxide. On Days 21 and 22 mice were topically challenged twice daily with 150µg per eye of SRW. The right eye of each mouse was evaluated at baseline and 18 minutes post topical challenge using a modified Micron III imaging system. Allergic responses were evaluated with Ora’s proprietary scale where each endpoint (hyperemia, discharge, and squinting) was measured on a scale of 0-4.
Results:
Out of six strains, Balb/C mice were the most affected by topical SRW. The Balb/C mice had a change from baseline redness score of approximately 2 units. No other strain showed an increase in hyperemia after topical challenge. Balb/C mice were statistically higher versus B6(Cg)- Tyrc-2J/J, SWR/J, and Swiss Webster (p<0.01, p<0.001, and p<0.001, respectively). No significance was noted versus the B6 Albino or CD1 mice for hyperemia. Discharge scores showed little increase from baseline in any strain (about a 0.5 unit increase on average). Balb/C mice showed the most consistent increase in squinting scores vs. baseline; increases with this strain were significantly higher than B6 Albino, Swiss Webster, and CD1 mice (p<0.001, p<0.001, and p<0.01, respectively). No significance was noted versus the B6 (Cg)-Tyrc-2J/J or SWR/J mice.
Conclusions:
Out of the 6 strains surveyed, Balb/C mice continue to be the most sensitive strain for evaluating novel drugs to treat allergic conjunctivitis.
Keywords: 475 conjunctivitis •
479 cornea: clinical science •
557 inflammation