Mixed lymphocyte reaction with autologous lung cells as targets for responder splenocytes or thymocytes. (a) For each animal, the maximal responses of thymocytes to autologous lung cells and to PHA are given. (b) The ratio of maximal responsiveness to lung versus PHA was calculated and the results pooled for both thymocytes and splenocytes from each group, as shown: 125-d GCs (125GC; n = 2), 125-d/PRN × 6 d (n = 3), 125-d/PRN × 14 d (n = 3), 125-d/PRN × 14 d + 2A11 (n = 4), and 140-d GC (n = 4). Note that the 140-d GC group is an age-matched control for the 125-d/PRN × 14-d animals. *p < 0.03; †p < 0.003 compared with 140-d GCs. **p < 0.03 compared with 125-d/PRN × 14 d with no intervention.