The law, passed by a Republican-led legislature and signed by a Republican governor, is due to take effect on Aug. 1. The lawsuit was filed in U.S. district court in Austin on Wednesday.

The law permits concealed-handgun license holders 21 and older to bring handguns into classrooms and buildings throughout the University of Texas system, one of the nation's largest, with an enrollment of more than 214,000 students.

"Compelling professors at a public university to allow, without any limitation or restriction, students to carry concealed guns in their classrooms chills their First Amendment rights to academic freedom," the lawsuit stated.

The lawsuit filed by professors Jennifer Lynn Glass, Lisa Moore and Mia Carter names defendants including the state's Republican attorney general, the school's president and the university's board of regents.