Heat grill. In large bowl, combine all ingredients except buns; mix well. Shape mixture into 4 patties, 1/2 inch thick.
When ready to grill, lightly oil grill rack. Place patties on gas grill over medium heat or on charcoal grill 4 to 6 inches from medium coals. Cook 10 to 12 minutes or until patties are no longer pink in center, turning once.
Meanwhile, place buns, cut side down, on grill. Cook 1 to 2 minutes or until lightly toasted. Place patties in buns. If desired, serve with ketchup and pickle slices.