Alexis Bledel and Curt Bouril (“Boardwalk Empire”) are among the thesps joining Adriane Lenox in the Off Broadway world preem of “Regrets” at Manhattan Theater Club this spring.Ansel Elgort, Brian Hutchison, Lucas Caleb Rooney and Richard Topol also have signed on to appear in the play by Matt Charman, the Brit playwright making his Gotham bow with the show. Storyline centers on a young man (Elgort) and the people he meets at a 1950s Nevada retreat that specializes in quickie divorces. Previous Off Broadway credits for Bledel (“Gilmore Girls”) include a stint in “Love, Loss and What I Wore.” On the bigscreen she recently played one of the title characters in “Violet and Daisy,” which bowed at Toronto last year. “Regrets” will be the final show in MTC’s 2011-12 season at City Center, the troupe’s Off Broadway venue. At the org’s Broadway house, the Friedman, the current, well-received staging of “Wit” will make way later this spring for David Auburn’s “The Columnist” starring John Lithgow. Helmed by Carolyn Cantor, “Regrets” begins preview March 8 ahead of a March 27 opening.