The ornamental design for a tire tread, as shown and described.
1. Tire tread
1.1 is a side elevation view of the tire tread showing my new invention;
1.2 is an opposing side elevation view thereof;
1.3 is a front perspective view thereof;
1.4 is a front elevation view thereof; and
1.5 is an enlarged partial front elevation view thereof, wherein the area of enlargement is indicated by broken line annotations 1.5-1.5 as shown in reproduction 1.4.
The broken lines showing the sidewalls and other portions of the tire are provided for the purposes of illustrating environmental structure and forms no part of the claimed design. Additionally, in reproduction 1.4, the broken line annotations of 1.5-1.5 are graphical indications for the area enlargement and do not form part of the claimed design.