Tuna Tortilla Roll Ups

4 cups water packed tuna, drained and flaked
8 lettuce leaves
1/2 cup celery, finely chopped
1 cup, diced green apple
1/2 cup light mayonnaise
8 (8  inch) whole grain flour or corn tortillas
In a medium bowl, combine tuna, celery, apple and mayonnaise. Top tortilla with lettuce leaf and tuna salad.  Roll up tightly.