I claim the ornamental design for a tire tread, as shown and described.
FIG. 1 is a perspective view of a tire tread as shown in a section defined by lines A-A and B-B; and,
FIG. 2 is an enlarged view of the tire tread shown as the section defined by lines A-A and B-B in FIG. 1.
In FIGS. 1-2, the dash/dot/dash/dot broken lines depict claim boundaries and form no part of the claim; the evenly spaced broken lines illustrate portions of the article that form no part of the claimed design.