title: Effect of Ureaplasma parvum co-incubation on Chlamydia trachomatis maturation in human epithelial HeLa cells treated with interferon-γ.
abstract: Chlamydia trachomatis is an obligate intracellular bacterium that causes a sexually transmitted disease. Ureaplasma parvum is commensal in the human genital tract, with a minimal contribution to urogenital infection. We have recently found that U. parvum has a significant effect on the presence of C. trachomatis in the genital tract of healthy women. We therefore assessed the effect of U. parvum co-incubation on C. trachomatis maturation from reticulate bodies (RBs) to elementary bodies (EBs) in HeLa cells in the absence or presence of interferon (IFN)-γ, which is a critical host defense factor. IFN-γ stimulation of viable U. parvum significantly prompted chlamydial growth with an increase in infectious particles, EBs, in HeLa cells. IFN-γ treatment of killed U. parvum had a similar effect on C. trachomatis maturation in HeLa cells. There was no change in expression of indoleamine 2,3-dioxygenase (IDO) in cultures of viable or killed U. parvum. We concluded that U. parvum co-incubation by IFN-γ helped C. trachomatis to mature from RBs to EBs in HeLa cells, independent of IDO expression. This suggests a novel survival strategy of C. trachomatis against IFN-γ exposure, prompting secondary infection of the genital mucosa, with possible clinical implications.
authors.affiliation: Department of Medical Laboratory Science, Faculty of Health Sciences, Hokkaido University, Nishi-5 Kita-12 Jo, Kita-ku, Sapporo, Hokkaido 060-0812, Japan. Electronic address: never_i_stand_by_you@ec.hokudai.ac.jp.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Yamazaki
authors.affiliation: Department of Medical Laboratory Science, Faculty of Health Sciences, Hokkaido University, Nishi-5 Kita-12 Jo, Kita-ku, Sapporo, Hokkaido 060-0812, Japan. Electronic address: matsuo@hs.hokudai.ac.jp.
authors.forename: Junji
authors.initials: J
authors.lastname: Matsuo
authors.affiliation: Division of Biomedical Imaging Research, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan. Electronic address: shinji-n@juntendo.ac.jp.
authors.forename: Shinji
authors.initials: S
authors.lastname: Nakamura
authors.affiliation: Hokkaido University Hospital, Nishi-5 Kita-14 Jo, Kita-ku, Sapporo, Hokkaido 060-8648, Japan. Electronic address: s-oguri@med.hokudai.ac.jp.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Oguri
authors.affiliation: Department of Medical Laboratory Science, Faculty of Health Sciences, Hokkaido University, Nishi-5 Kita-12 Jo, Kita-ku, Sapporo, Hokkaido 060-0812, Japan. Electronic address: hiroyuki@med.hokudai.ac.jp.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Yamaguchi
mesh_terms: D002690:Chlamydia Infections / Q000382:microbiology*; D002692:Chlamydia trachomatis / Q000187:drug effects / Q000254:growth & development; D018920:Coculture Techniques; D060085:Coinfection / Q000382:microbiology*; D005260:Female; D006367:HeLa Cells; D006801:Humans; D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase / Q000032:analysis / Q000378:metabolism; D007371:Interferon-gamma / Q000494:pharmacology*; D008954:Models, Biological; D014509:Ureaplasma / Q000187:drug effects*; D016869:Ureaplasma Infections / Q000382:microbiology*
chemical_list: D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase; D007371:Interferon-gamma
keywords: Chlamydia trachomatis; Indoleamine 2,3-dioxygenase; Interferon-γ; Mixed infection; Ureaplasma parvum