The ornamental design for a tire tread, as shown and described.
FIG. 1 is a front elevational view of the tire tread, it being understood that the tread pattern is repeated throughout the circumference of the tire tread, the opposite side being the same as that shown.
FIG. 2 is a front angled perspective view of the tire tread, it being understood that the tread pattern is repeated throughout the circumference of the tire tread; and,
FIG. 3 is a side elevational view of the right side of the tire tread, the opposite side being identical thereto.
In the drawings, the broken lines defining the sidewall, inner bead and the peripheral boundary between the claimed tire tread and the unclaimed sidewall depict environmental subject matter that forms no part of the claimed design.