The ornamental design for a tire tread, as shown and described.
FIG. 1 is a perspective view of a tire tread showing my new design, it
being understood that the tread pattern is repeated throughout the
circumference of the tire tread;
FIG. 2 is a front elevational view thereof; and
FIG. 3 is a side elevational view thereof.
The broken lines in the drawing are for illustrative purposes only.