The ornamental design for a tire tread, as shown and described.
FIG. 1 is a perspective view of a tire tread according to our new ornamental design; and,
FIG. 2 is a front view thereof.
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.