Figure 6. Transfer of protection against allergy with thoracic lymph node cells from T. gondii infected and sensitized mice.

Experimental design: TLN were removed from TO, T, and naïve mice and injected iv in mice previously ip sensitized twice with OVA. Twenty four hours later, mice were exposed to aerosols of allergen on 3 consecutive days (A). Bronchoalveolar lavage was performed 48 h. after the last exposure to OVA. BAL differential cell counts were performed on cytocentrifuge slides, fixed and stained with a modified Wright-Giemsa stain. * p<0.05 TO vs N, ANOVA with Bonferroni a posteriori (B). After lavage, lungs were instilled and fixed with 10% buffered formalin. Following paraffin embedding, sections for microscopy were stained with Hematoxylin and PAS (C). An index of pathologic changes in H&E slides was obtained by scoring the inflammatory infiltrate around the airways and vessels for greatest severity (0, normal; 1, <4 cells diameter thick; 2, 4–10 cells diameter thick; 3, >10 cells diameter thick) and overall extent (0, normal; 1, <25% of sample; 2, 26–50%; 3, 51–75%; 4, >75%). The Index was calculated by multiplying severity by extent. * p<0.05 N vs T and TO, ANOVA with Bonferroni a posteriori (D). An histological goblet cell score was obtained in Periodic acid-Schiff (PAS)-stained lung sections by examining 10 to 20 consecutive airways from all groups of mice at 40x magnification and categorized according to the abundance of PAS-positive goblet (0, <5% goblet cells; 1, 5–25%; 2, 26–50%; 3, 51–75%; 4, >75%). The Index was calculated by dividing the sum of the airway scores from each lung by the number of airways examined for the histological goblet cell score. Original magnification×200. * p<0.05 N vs TO; ANOVA with Bonferroni a posteriori (E).