The ornamental design for a tire tread, as shown and described.
FIG. 1 is a front elevational view of a tire tread showing my new design, it being understood that the pattern repeats uniformly throughout the circumference of the tread; and,
FIG. 2 is an enlarged fragmentary front elevation view thereof.
In the drawings, the broken lines defining the sidewall and the central portion of the tread are for illustrative purposes only and form no part of the claimed design.