Synergistic and Cytotoxic Effects of the Combination of Inerolysin and Vaginolysin Toxins on VK2 and HeLa Cells Isolated from an Iraqi Woman Who had an Abortion

Abstract

Objective: The goal of this study is to purify inerolysin produced by Lactobacillus iners and vaginolysin produced by Gardnerella vaginalis, and to investigate the cytotoxic effects of the combination of these purified toxins on VK2 and HeLa cells. Methods: Out of 592 specimens from Baghdad teaching hospitals, 101 isolates were identified as L. iners and 165 isolates as G. vaginalis. The toxins were purified using ammonium sulfate precipitation, ion exchange chromatography, and gel filtration. The cytotoxic effects of the combined inerolysin and vaginolysin on VK2 and HeLa cells were studied. Results: For inerolysin, the optimal precipitation saturation ratio was 70%, with ion exchange chromatography yielding a specific activity of 14 mg and gel filtration increasing the specific activity to 40 U/mg. For vaginolysin, the optimal precipitation saturation ratio was 50%, with ion exchange chromatography yielding a specific activity of 4 mg and gel filtration increasing the specific activity to 10 U/mg. The combination of toxins showed a viability ratio of 38% for VK2 cells and 31% for HeLa cells at higher toxin concentrations. Conclusion: Inerolysin and vaginolysin cause lysis of vaginal and cervical cells, which may lead to abortion. The killing ratio increases with higher concentrations of the toxins.