TOSS first 4 ingredients with Italian dressing; let stand 10 min.
MEANWHILE, cut bread horizontally in half; hollow out each half, leaving 1/2-inch-thick shell. Discard removed bread or reserve for another use. (See Tip.) Spread insides of bread shells with MIRACLE WHIP.
DRAIN vegetable mixture; discard dressing. Layer turkey, Singles, vegetable mixture and lettuce in bottom half of bread; cover with top of bread. Cut into wedges.