Studies on Gonococcus Infection. XVII. IgA1-Cleaving Protease in Vaginal Washings from Women with Gonorrhea

Abstract

Vaginal washings from women attending a venereal disease clinic were examined for the presence of protease that cleaved IgA subclass 1 (IgA₁). In a crude assay, vaginal washings cleaved [¹²⁵I]IgA₁ in 19 of 25 specimens from individuals from whom Neisseria gonorrhoeae were cultivated. Forty-six specimens from 104 women whose cultures were negative for N. gonorrhoeae also cleaved [¹²⁵I]IgA₁. Vaginal washings from six of six women with culture-proven gonorrhea cleaved [¹²⁵I]IgA₁ into low-molecular-weight components identical to those produced by partially purified IgA1specific protease from gonococci. The hydrolysis of [¹²⁵I]IgA₁ by vaginal washings from women whose cultures were negative for N. gonorrhoeae yielded cleavage products that resembled those of trypsin or α-chymotrypsin. These findings indicate that gonococci residing in the female genital tract produce IgA₁-specific protease that can be detected in the vaginal washings of infected women.