In the control group absolute lymphoblast output peaked at day 10 with 3·25 ± 0·8 × 108 cells/h, significantly higher than the pre-challenge output of around 0·5 × 108 cells/h. In both groups, the lymphoblast output had returned to pre-challenge levels

by the end of the experiment. A CD4+ blast cell response was observed in both the control and previously infected groups of lambs, with a repeated measures model showing strong evidence of a difference in the pattern of responses over time between the two groups (P < 0·001). In the control group, the CD4+ blast cell response peaked at day 10 at 1·58 ± 0·19 × 107 cells/h (Figure 4a), HKI-272 purchase and in the previously infected group peaked at day 3 at 0·9 ± 0·24 × 107 cells/h (Figure 4b). A CD8+ blast cell response was observed in the controls but not in the previously infected group (Figure 4c, d). No significant changes were observed in the gamma-delta T cell receptor positive blast cell response of either group of lambs (Figure 4e, f), the increase in mean output observed on day 12 in the controls being caused by a single outlier animal. Prior

to challenge, three of the previously infected lambs had elevated levels of γ/δ TCR+ blast cells (Figure 4f), however these had subsided by day 1. The CD25+ blast cell response was similar to CD4, with strong evidence of a difference in pattern selleckchem of response between the two groups (P < 0·001). Naïve lambs showed

an increase in CD25+ blast cells from day 5, peaking at day 10 at 1·76 ± 0·3 × 107 cells/h (Figure 4g). In the previously infected group the response occurred sooner, peaking on day 3 at 1·30 ± 0·3 × 107 cells/h (Figure 4h). In the naïve group a CD21+ blast cell response was observed which peaked on day 10 at 0·76 ± 0·1 × 107 cells/h (Figure 5a), significantly (P < 0·05) higher than the pre-challenge output of 0·16 ± 0·1 × 107 cells/h. The same response occurred more quickly in the previously infected lambs peaking on day 5 at 0·73 ± 0·2 × 107 cells/h (Figure 5b). The repeated measures model showed inconclusive evidence (P = 0·068) of a difference in the pattern of responses between the two groups, due in part to relatively high estimated standard errors. IgA+ Aspartate blast cell output was increased 10 and 12 days after the naïve lambs were infected, peaking at 0·51 ± 0·1 × 107 cells/h (Figure 5c), and in the previously infected group peaked on day 3 at 0·23 ± 0·1 × 107 cells/h (Figure 5d). This led to strong evidence of a difference in pattern of response over time between the two groups (P < 0·001). Before challenge mean total IgA concentrations in the efferent gastric lymph of control and previously infected lambs were similar, at 0·53 ± 0·2 and 0·34 ± 0·04 mg/mL respectively (Figure 6a, b).