The ornamental design for a tire tread, as shown and described.
FIG. 1 is a perspective view of a tire tread showing our new design, it being understood that the pattern repeats uniformly throughout the circumference of the tread;
FIG. 2 is an enlarged front elevational view thereof; and,
FIG. 3 is a reduced scale right side elevational view thereof, the other side being a mirror image of the right side thereof.
In the drawings, the broken lines defining the sidewall and inner bead are for illustrative purposes only and form no part of the claimed design.