HEAT grill to medium heat.
MIX first 3 ingredients; shape into 4 (1/2-inch-thick) patties. Brush 1/4 cup barbecue sauce evenly onto cut sides of buns.
GRILL patties 8 min.; turn. Brush with remaining barbecue sauce. Grill 4 min. or until burgers are done (160ºF). Top burgers with cheese and add buns, cut sides down, to grill. Grill 1 min. or until cheese is melted and buns are lightly toasted.
FILL buns with lettuce, tomatoes and cheeseburgers.