CP30, a Cysteine Proteinase Involved in Trichomonas vaginalis Cytoadherence

Abstract

We describe here the participation of a Trichomonas vaginalis 30-kDa proteinase (CP30) with affinity to the HeLa cell surface in attachment of this parasite to host epithelial cells. The CP30 band is a cysteine proteinase because its activity was inhibited by E-64, a thiol proteinase inhibitor. In two-dimensional substrate gel electrophoresis of total extracts of the trichomonad isolate CNCD 147, three spots with proteolytic activity were detected in the 30-kDa region, in the pI range from 4.5 to 5.5. Two of the spots (pI 4.5 and 5.0) bound to the surfaces of fixed HeLa cells corresponding to the CP30 band. The immunoglobulin G fraction of the rabbit anti-CP30 antiserum that recognized a 30-kDa band by Western blotting and immunoprecipitated CP30 specifically inhibited trichomonal cytoadherence to HeLa cell monolayers in a concentration-dependent manner and reacted with CP30 at the parasite surface. CP30 degraded proteins found on the female urogenital tract, including fibronectin, collagen IV, and hemoglobin. Interestingly, CP30 digested fibronectin and collagen IV only at pH levels between 4.5 and 5.0. Moreover, trichomonosis patients whose diagnosis was confirmed by in vitro culture possessed antibody to CP30 in both sera and vaginal washes, and CP30 activity was found in vaginal washes. Our results suggest that surface CP30 is a cysteine proteinase necessary for trichomonal adherence to human epithelial cells.

Mechanisms ofTritrichomonas foetusPathogenicity in Cats with Insights from Venereal Trichomonosis

“…At least 23 and 15 different cysteine proteases have been identified in T. vaginalis and bovine T. foetus , respectively 60, 67, 68, 69, 70. At least three T. vaginalis surface‐expressed cysteine proteases (CP30, CP65 and TvLEGU‐1) play a key role in adhesion and adhesion‐dependent cytotoxicity to cervical and vaginal epithelial cells 48, 66, 71, 72, 73, 74…”

“…Furthermore, T. vaginalis with mutated, truncated LPG adhere 7‐fold less and induce significantly less cytotoxicity to ectocervical cells compared to parent strains 65. Finally, anti‐cysteine protease antibodies significantly inhibit adhesion and decrease the cytotoxicity of T. vaginalis to HeLa cell monolayers 71, 72…”

“…Many of the T. vaginalis cysteine proteases have been identified in vaginal secretions from infected women 84, 85. The cytotoxic effects of cysteine proteases include degradation of mucus, complement and immunoglobulin, and destruction of extracellular matrix (fibronectin, several types of collagen, and laminin) 43, 72, 73, 84, 86, 87. Cysteine proteases therefore can function as epithelial cell detaching factors and can mediate direct cytotoxic effects on vaginal and uterine epithelial cells by induction of apoptosis72, 73, 84, 88, 89, 90 (Fig 1D).…”

Comparative aspects of immunity and vaccination in human and bovine trichomoniasis: a review

“…Both are extracellular parasites which penetrate the mucus barrier and parasitize the genital epithelium. Cyto-adherence is necessary for pathogenicity Mendoza-Lopez et al 2000). In the reproductive tract, the trichomonads colonize and establish an infection by adhering to the vagina and then subsequently ascending to the cervix and uterus (Mendoza-Lopez et al 2000).…”

“…Cyto-adherence is necessary for pathogenicity Mendoza-Lopez et al 2000). In the reproductive tract, the trichomonads colonize and establish an infection by adhering to the vagina and then subsequently ascending to the cervix and uterus (Mendoza-Lopez et al 2000). This progressive invasion of the genital tract results in varying degrees of inflammation with consequent transient or permanent sterility (BonDurant 1997).…”