A New York University liberal studies professor known for his tweets fighting back against PC culture filed a defamation lawsuit against the school and four colleagues last week over a string of claims he said were false, the New York Post reported.

Plaintiff Michael Rectenwald's case named the school, associate professor Jacqueline Bishop, adjunct professor Amber Frost, professor Carley Moore and Theresa Senft, whom the Post described as an ex-assistant professor, as defendants.

Rectenwald alleged that a May email thread sent to more than 100 NYU staffers included “malicious” statements -- and that NYU didn’t prevent the “nasty screed,” the Post reported. The emails reportedly called him an “Adderall-filled bully” and “right-wing misogynist,” among other things.

Frost responded to Fox News briefly in an email: "lol."

The university and the other three defendants did not respond to Fox News' requests for comment.

Rectenwald is known for using the Twitter handle @antipcnyuprof and tweeting under the pseudonym “Deplorable NYU Prof.” He came forward in October 2016.

His lawsuit claimed Senft made fun of him in an email to the liberal studies department in May 2017 -- one day after he tweeted about a “deplorable prof”-related advance from a publisher, the Post added.

Bishop, Frost and Moore are among those accused of making disparaging remarks.

Frost allegedly said Rectenwald was a “right-wing misogynist,” while Bishop allegedly claimed Rectenwald arrived at staff meetings “high and incoherent with your tongue sticking out the side of your mouth.”

“It’s very painful to be accused of things that you haven’t done and have no basis in fact,” Rectenwald told the newspaper.

A NYU spokesman told the Post, “This lawsuit is without merit.”