title: A domino-like chlamydial attachment process: concurrent Parachlamydia acanthamoebae attachment to amoebae is required for several amoebal released molecules and serine protease activity.
abstract: Parachlamydia acanthamoebae is an obligate intracellular bacterium that infects free-living amoebae (Acanthamoeba), and is a potential human pathogen associated with hospital-acquired pneumonia. The attachment mechanism of this bacteria to host cells is crucial in bacterial pathogenesis, yet remains undetermined. Hence, we obtained monoclonal antibodies (mAbs) specific to either P. acanthamoebae or amoebae in an attempt to elucidate the attachment mechanism involved. Hybridomas of 954 clones were assessed, and we found that four mAbs (mAb38, mAb300, mAb311, mAb562) that were reactive to the amoebae significantly inhibited bacterial attachment. All mAbs recognized amoebal released molecules, and mAb311 also recognized the amoebal surface. mAbs reacted with the bacteria not only within amoebae, but also when they were released from amoebae (except mAb311). Furthermore, a serine protease inhibitor had an inhibitory effect on the bacterial attachment to amoebae, although none of the mAbs had any synergistic effect on the inhibition of attachment by the protease inhibitor. Taken together, we conclude that concurrent P. acanthoamebae attachment to amoebae is required for several amoebal released molecules and serine protease activity, implying the existence of a complicated host-parasite relationship.
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.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Hayashi
authors.affiliation: Department of Advanced Medicine, Graduate School of Medicine, Hokkaido University, Nishi-7, Kita-15, Kita-ku, Sapporo 060-8638, Japan.
authors.lastname: Yimin
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.
authors.forename: Junji
authors.initials: J
authors.lastname: Matsuo
authors.affiliation: Division of Biomedical Imaging Research, Juntendo University Graduate School of Medicine, Bunkyo-ku, Tokyo 113-8421, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Nakamura
authors.affiliation: Division of Biomedical Imaging Research, Juntendo University Graduate School of Medicine, Bunkyo-ku, Tokyo 113-8421, Japan.
authors.forename: Miyuki
authors.initials: M
authors.lastname: Kunichika
authors.affiliation: Division of Ultrastructural Research, Juntendo University Graduate School of Medicine, Bunkyo-ku, Tokyo 113-8421, Japan.
authors.forename: Mitsutaka
authors.initials: M
authors.lastname: Yoshida
authors.affiliation: Division of Ultrastructural Research, Juntendo University Graduate School of Medicine, Bunkyo-ku, Tokyo 113-8421, Japan.
authors.forename: Kaori
authors.initials: K
authors.lastname: Takahashi
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.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Yamaguchi
mesh_terms: D000048:Acanthamoeba / Q000201:enzymology / Q000235:genetics / Q000378:metabolism / Q000382:microbiology*; D001422:Bacterial Adhesion; D002695:Chlamydiales / Q000235:genetics / Q000502:physiology*; D006790:Host-Parasite Interactions; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism*; D057057:Serine Proteases / Q000235:genetics / Q000378:metabolism*
chemical_list: D015800:Protozoan Proteins; D057057:Serine Proteases