title: Cell-to-cell contact of human monocytes with infected arterial smooth-muscle cells enhances growth of Chlamydia pneumoniae.
abstract: Chlamydia pneumoniae can infect arterial cells. It has been shown that coculture of human monocytes (U937) and endothelial cells promotes infection of C. pneumoniae in endothelial cells and that the enhancement was mediated by a soluble factor (insulin-like growth factor 2) secreted by monocytes. In this study, it is shown that coculture of monocytes with C. pneumoniae enhances infection of C. pneumoniae in arterial smooth-muscle cells 5.3-fold at a monocyte-to-smooth-muscle cell ratio of 5. However, unlike endothelial cells, no enhancement was observed if monocytes were placed in cell culture inserts or if conditioned medium from monocyte cultures was used, which suggests that cell-to-cell contact is critical. The addition of mannose 6-phosphate or octyl glucoside, a nonionic detergent containing a sugar group, to cocultures inhibited the enhancement. These findings suggest that the monocyte-smooth-muscle cell interaction may be mediated by mannose 6-phosphate receptors present on monocytes.
authors.affiliation: Department of Pathobiology, University of Washington, Seattle, Washington 98195, USA.
authors.forename: Mirja
authors.initials: M
authors.lastname: Puolakkainen
authors.forename: Lee Ann
authors.initials: LA
authors.lastname: Campbell
authors.forename: Tsun-Mei
authors.initials: TM
authors.lastname: Lin
authors.forename: Theresa
authors.initials: T
authors.lastname: Richards
authors.forename: Dorothy L
authors.initials: DL
authors.lastname: Patton
authors.forename: Cho-Chou
authors.initials: CC
authors.lastname: Kuo
mesh_terms: D001158:Arteries / Q000166:cytology*; D002448:Cell Adhesion; D016993:Chlamydophila pneumoniae / Q000187:drug effects / Q000254:growth & development*; D018920:Coculture Techniques; D017077:Culture Media, Conditioned; D005960:Glucosides / Q000494:pharmacology; D006801:Humans; D007335:Insulin-Like Growth Factor II / Q000494:pharmacology; D008360:Mannosephosphates / Q000494:pharmacology; D009000:Monocytes / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D009131:Muscle, Smooth, Vascular / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism / Q000382:microbiology; D032389:Myocytes, Smooth Muscle / Q000166:cytology* / Q000187:drug effects / Q000382:microbiology*; D017527:Receptor, IGF Type 2 / Q000378:metabolism
chemical_list: D017077:Culture Media, Conditioned; D005960:Glucosides; D008360:Mannosephosphates; D017527:Receptor, IGF Type 2; C018619:octyl-beta-D-glucoside; C027693:mannose-6-phosphate; D007335:Insulin-Like Growth Factor II