NEW YORK - A Columbia University student filed a lawsuit against the school Thursday, saying it failed to protect him against harassment when a female student went public with claims he raped her after school and law enforcement authorities rejected her case.

The lawsuit was filed in Manhattan federal court by Paul Nungesser, a German citizen and senior at Columbia University who says onetime friend Emma Sulkowicz, who is also a senior at the school, has repeatedly and publicly called him a "serial rapist," resulting in national and international media attention.

Defendants of the lawsuit include the school, its board of trustees, University President Lee C. Bollinger and Professor Jon Kessler. The lawsuit seeks unspecified damages.

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"Columbia University's effective sponsorship of the gender-based harassment and defamation of Paul resulted in an intimidating, hostile, demeaning ... learning and living environment," the lawsuit says.

Robert Hornsby, a Columbia spokesman, said the school had no comment. Email messages requesting comment from Bollinger and Kessler were not immediately returned. The suit was filed three days after a judge tossed out another gender-based lawsuit brought by a male student against Columbia University.

In his lawsuit, Nungesser says a Columbia-owned website presented as fact that he sexually assaulted Sulkowicz, a senior majoring in visual arts. It also alleges that the school allowed Sulkowicz to carry a mattress into classes, the library and campus-provided transportation as part of her senior thesis and that Kessler approved the "Mattress Project" for her course credit. It goes on to say that Sulkowicz's pledge to carry her mattress to graduation may prevent Nungesser and his parents, who'd like to fly from Germany, from participating in graduation ceremonies.

"Day-to-day life is unbearably stressful, as Emma and her mattress parade around campus each and every day," the suit says.

As a result of publicity that resulted in media reports in 35 countries, the lawsuit says, Nungesser "has been subjected to severe, pervasive ... and threatening behavior by other Columbia students, believing that Paul is a 'serial rapist,' whenever Paul has appeared at university activities."

The suit also says Nungesser wants to stay in the United States, where he has been dating a girlfriend for over a year, and is seeking consulting work in New York, but job prospects have been "severely jeopardized" by the school's support of Sulkowicz.

In an email responding to a request for comment, Sulkowicz wrote: "I think it's ridiculous that Paul would sue not only the school but one of my past professors for allowing me to make an art piece."

"It's ridiculous that he would read it as a 'bullying strategy,' especially given his continued public attempts to smear my reputation, when really it's just an artistic expression of the personal trauma I've experienced at Columbia. If artists are not allowed to make art that reflect on our experiences, then how are we to heal?"

Sulkowicz has argued her case was badly mishandled by the school disciplinary panel after she reported in 2013 she was raped in her dorm months before. She was among 23 students who sued Columbia last year, saying it mishandled sexual assault cases. She also attended President Barack Obama's State of the Union address in January at the invitation of Sen. Kirsten Gillibrand, D-N.Y.

The Associated Press and CBS News normally do not identify people claiming they were sexually assaulted, but make exceptions when the alleged victim has spoken publicly on the subject.