Mink epithelial cell killing by pathogenic murine leukemia viruses involves endoplasmic reticulum stress.
We previously demonstrated that mink cells undergo apoptosis after MCF13 murine leukemia virus (MLV) infection. In this study, we observed that virus-infected mink epithelial cells had significantly larger amounts of steady-state levels of MCF13 MLV envelope precursor protein (gPr80(env)) than did Mus dunni fibroblasts, which are resistant to virus-induced cytopathicity. Infection of mink cells with the noncytopathic NZB-9 MLV did not result in the accumulation of gPr80(env). MCF13 MLV infection of mink cells produced low cell surface expression of envelope glycoprotein and less efficient spread of infectious virus. Western blot analysis of mink epithelial cells infected with MCF13 MLV showed an increase in GRP78/BiP, which was not observed for either mink cells infected with NZB-9 MLV or M. dunni fibroblasts infected with MCF13 MLV. MCF13 MLV infection of mink cells also resulted in a significant upregulation of CHOP/GADD153. These results indicate that the accumulation of MCF13 MLV gPr80(env) triggers endoplasmic reticulum stress, which may mediate apoptosis in mink epithelial cells.
Nanua
Suparna
S
Department of Immunology and Microbiology, Karmanos Cancer Institute, Wayne State University, 540 E. Canfield Ave., Detroit, MI 48201, USA.
Yoshimura
Fayth K
FK
D000818:Animals; D017209:Apoptosis; D022762:CCAAT-Enhancer-Binding Proteins / Q000032:analysis; D004721:Endoplasmic Reticulum / Q000502:physiology*; D000091342:Endoplasmic Reticulum Chaperone BiP; D004847:Epithelial Cells / Q000473:pathology; D015686:Gene Products, env / Q000378:metabolism; D006360:Heat-Shock Proteins / Q000032:analysis; D008907:Mink; D008908:Mink Cell Focus-Inducing Viruses / Q000472:pathogenicity*; D018832:Molecular Chaperones / Q000032:analysis; D051742:Transcription Factor CHOP; D014157:Transcription Factors / Q000032:analysis
D022762:CCAAT-Enhancer-Binding Proteins; D000091342:Endoplasmic Reticulum Chaperone BiP; D015686:Gene Products, env; D006360:Heat-Shock Proteins; D018832:Molecular Chaperones; D014157:Transcription Factors; D051742:Transcription Factor CHOP