“True Blood” thesp Stephen Moyer and Lily Collins of “90210” have joined “Priest,” the Scott Stewart-directed Screen Gems thriller that stars Paul Bettany, Cam Gigandet and Maggie Q.Scripted by Cory Goodman, the thriller involves a warrior priest who turns against the church to track down a murderous band of vampires who kidnapped his niece. Though he’s known for playing a bloodsucker in HBO’s hit vampire drama, in this feature film foray Moyer will play the mortal brother of the protagonist. Collins, who just starred with Sandra Bullock and Tim McGraw in “The Blind Side,” plays the niece. Michael De Luca produces with Josh Donen and Mitchell Peck. Pic is skedded to begin shooting today. Moyer is repped by ICM and Luber/Rocklin, and Collins by CAA.