PURPOSE: Human retinal pigment epithelial (RPE) cells and endothelial cells (HUVECs) are targets of human cytomegalovirus (HCMV) infection in vivo with significantly protracted replication in vitro compared with that in fibroblasts. This study analyzes the kinetics and mechanisms of HCMV entry into both cell types. METHODS: RPE cells were obtained from donor eyes. HUVECs were isolated from human umbilical cords. HCMV entrance was followed by electron microscopy and immunofluorescence in the presence of lysosomotropic agents and cytochalasin B. RESULTS: Human cytomegalovirus entered into RPE cells and HUVECs as early as 5 minutes after virus- cell contact. Entry was mediated by endocytosis, whereas HCMV enters fibroblasts through fusion. Most internalized viral particles and dense bodies appeared to be degraded within vacuoles. Viral entry, transport of viral proteins to the nucleus, and onset of viral transcription (immediate early [IE] protein expression) were significantly blocked by cytochalasin B. Lysosomotropic agents did not significantly reduce IE expression in RPE cells or HUVECs. CONCLUSIONS: This study shows that HCMV penetrates these highly specialized relevant cells via endocytosis. The low level of infection and the delay in the onset of HCMV expression seen in these cells compared with fibroblasts may be related to the sequestration and degradation of incoming viral particles in endocytic vacuoles.
PURPOSE:Humanretinal pigment epithelial (RPE) cells and endothelial cells (HUVECs) are targets of human cytomegalovirus (HCMV) infection in vivo with significantly protracted replication in vitro compared with that in fibroblasts. This study analyzes the kinetics and mechanisms of HCMV entry into both cell types. METHODS: RPE cells were obtained from donor eyes. HUVECs were isolated from human umbilical cords. HCMV entrance was followed by electron microscopy and immunofluorescence in the presence of lysosomotropic agents and cytochalasin B. RESULTS:Human cytomegalovirus entered into RPE cells and HUVECs as early as 5 minutes after virus- cell contact. Entry was mediated by endocytosis, whereas HCMV enters fibroblasts through fusion. Most internalized viral particles and dense bodies appeared to be degraded within vacuoles. Viral entry, transport of viral proteins to the nucleus, and onset of viral transcription (immediate early [IE] protein expression) were significantly blocked by cytochalasin B. Lysosomotropic agents did not significantly reduce IE expression in RPE cells or HUVECs. CONCLUSIONS: This study shows that HCMV penetrates these highly specialized relevant cells via endocytosis. The low level of infection and the delay in the onset of HCMV expression seen in these cells compared with fibroblasts may be related to the sequestration and degradation of incoming viral particles in endocytic vacuoles.
Authors: Jens-Uwe Vogel; Jürgen Otte; Frank Koch; Hermann Gümbel; Hans Wilhelm Doerr; Jindrich Cinatl Journal: Med Microbiol Immunol Date: 2012-06-06 Impact factor: 3.402
Authors: Jung Heon Kim; Donna Collins-McMillen; Patrizia Caposio; Andrew D Yurochko Journal: Proc Natl Acad Sci U S A Date: 2016-07-18 Impact factor: 11.205
Authors: Richard S B Milne; Anthony V Nicola; J Charles Whitbeck; Roselyn J Eisenberg; Gary H Cohen Journal: J Virol Date: 2005-06 Impact factor: 5.103
Authors: Kumar G Janoria; Sai H S Boddu; Zhiying Wang; Durga K Paturi; Swapan Samanta; Dhananjay Pal; Ashim K Mitra Journal: J Ocul Pharmacol Ther Date: 2009-02 Impact factor: 2.671
Authors: Yujuan Yue; Amitinder Kaur; Anders Lilja; Don J Diamond; Mark R Walter; Peter A Barry Journal: J Gen Virol Date: 2016-03-14 Impact factor: 3.891