A Columbia University student who was accused of rape by a fellow student, who then targeted him in a very public campus action, filed a federal discrimination lawsuit on Thursday against the school; its president, Lee C. Bollinger; and one of its professors.

The plaintiff, Paul Nungesser, who was cleared of responsibility in the rape claim by the university, alleges in the lawsuit that he had been the victim of a harassment campaign by the other student, Emma Sulkowicz.

“By refusing to protect Paul Nungesser,” the lawsuit says, “Columbia University first became a silent bystander and then turned into an active supporter of a fellow student’s harassment campaign by institutionalizing it and heralding it.”

Ms. Sulkowicz’s case has drawn national attention, in part because she has carried a mattress around Columbia’s Morningside Heights campus, an action that she has called artistic expression and is her senior thesis, “Mattress Performance (Carry That Weight).”