Comparing Effects of BK Virus Agnoprotein and Herpes Simplex-1 ICP47 on MHC-I and MHC-II Expression

Background. Among human polyomaviruses, only BK virus (BKV) and JC virus (JCV) encode an agnoprotein upstream of VP1 on the viral late transcript. BKV agnoprotein is abundantly expressed late in the viral life cycle, but specific cellular and humoral immune responses are low or absent. We hypothesiz...

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Main Authors: Michela Cioni, Christian Mittelholzer, Marion Wernli, Hans H. Hirsch
Format: Article
Language:English
Published: Wiley 2013-01-01
Series:Clinical and Developmental Immunology
Online Access:http://dx.doi.org/10.1155/2013/626823
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author Michela Cioni
Christian Mittelholzer
Marion Wernli
Hans H. Hirsch
author_facet Michela Cioni
Christian Mittelholzer
Marion Wernli
Hans H. Hirsch
author_sort Michela Cioni
collection DOAJ
description Background. Among human polyomaviruses, only BK virus (BKV) and JC virus (JCV) encode an agnoprotein upstream of VP1 on the viral late transcript. BKV agnoprotein is abundantly expressed late in the viral life cycle, but specific cellular and humoral immune responses are low or absent. We hypothesized that agnoprotein might contribute to BKV immune evasion by downregulating HLA expression, similar to Herpes simplex virus-1 ICP47. Methods UTA-6 or primary human renal proximal tubular epithelial cells (RPTEC) were co-transfected with plasmids constitutively expressing agnoprotein, or ICP47, and enhanced green-fluorescent protein (EGFP). EGFP-gated cells were analyzed for HLA-ABC and HLA-DR expression by flow cytometry. HLA-ABC and HLA-DR expression was also analyzed on UTA-6 bearing tetracycline-regulated agnoprotein or ICP47. Effects of agnoprotein on viral peptide-dependent T-cell killing were investigated using 51Cr release. Results. ICP47 downregulated HLA-ABC without affecting HLA-DR, whereas agnoprotein did not affect HLA-ABC or HLA-DR expression. Interferon-γ treatment increased HLA-ABC in a dose-dependent manner, which was antagonized by ICP47, but not by agnoprotein. In UTA-6 cells, agnoprotein expression did neither impair HLA-ABC or -DR expression nor peptide-specific killing impaired by HLA-matched T-cells. Conclusion. Unlike the HSV-1 ICP47, BKV agnoprotein does not contribute to viral immune evasion by down-regulating HLA-ABC, or interfere with HLA-DR expression or peptide-dependent T-cell cytotoxicity.
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spelling doaj-art-7de794f8ab8146eb9efff53024b434702025-02-03T01:10:50ZengWileyClinical and Developmental Immunology1740-25221740-25302013-01-01201310.1155/2013/626823626823Comparing Effects of BK Virus Agnoprotein and Herpes Simplex-1 ICP47 on MHC-I and MHC-II ExpressionMichela Cioni0Christian Mittelholzer1Marion Wernli2Hans H. Hirsch3Transplantation & Clinical Virology, Department Biomedicine Haus Petersplatz, University of Basel, Petersplatz 10, CH-4003 Basel, SwitzerlandTransplantation & Clinical Virology, Department Biomedicine Haus Petersplatz, University of Basel, Petersplatz 10, CH-4003 Basel, SwitzerlandTransplantation & Clinical Virology, Department Biomedicine Haus Petersplatz, University of Basel, Petersplatz 10, CH-4003 Basel, SwitzerlandTransplantation & Clinical Virology, Department Biomedicine Haus Petersplatz, University of Basel, Petersplatz 10, CH-4003 Basel, SwitzerlandBackground. Among human polyomaviruses, only BK virus (BKV) and JC virus (JCV) encode an agnoprotein upstream of VP1 on the viral late transcript. BKV agnoprotein is abundantly expressed late in the viral life cycle, but specific cellular and humoral immune responses are low or absent. We hypothesized that agnoprotein might contribute to BKV immune evasion by downregulating HLA expression, similar to Herpes simplex virus-1 ICP47. Methods UTA-6 or primary human renal proximal tubular epithelial cells (RPTEC) were co-transfected with plasmids constitutively expressing agnoprotein, or ICP47, and enhanced green-fluorescent protein (EGFP). EGFP-gated cells were analyzed for HLA-ABC and HLA-DR expression by flow cytometry. HLA-ABC and HLA-DR expression was also analyzed on UTA-6 bearing tetracycline-regulated agnoprotein or ICP47. Effects of agnoprotein on viral peptide-dependent T-cell killing were investigated using 51Cr release. Results. ICP47 downregulated HLA-ABC without affecting HLA-DR, whereas agnoprotein did not affect HLA-ABC or HLA-DR expression. Interferon-γ treatment increased HLA-ABC in a dose-dependent manner, which was antagonized by ICP47, but not by agnoprotein. In UTA-6 cells, agnoprotein expression did neither impair HLA-ABC or -DR expression nor peptide-specific killing impaired by HLA-matched T-cells. Conclusion. Unlike the HSV-1 ICP47, BKV agnoprotein does not contribute to viral immune evasion by down-regulating HLA-ABC, or interfere with HLA-DR expression or peptide-dependent T-cell cytotoxicity.http://dx.doi.org/10.1155/2013/626823
spellingShingle Michela Cioni
Christian Mittelholzer
Marion Wernli
Hans H. Hirsch
Comparing Effects of BK Virus Agnoprotein and Herpes Simplex-1 ICP47 on MHC-I and MHC-II Expression
Clinical and Developmental Immunology
title Comparing Effects of BK Virus Agnoprotein and Herpes Simplex-1 ICP47 on MHC-I and MHC-II Expression
title_full Comparing Effects of BK Virus Agnoprotein and Herpes Simplex-1 ICP47 on MHC-I and MHC-II Expression
title_fullStr Comparing Effects of BK Virus Agnoprotein and Herpes Simplex-1 ICP47 on MHC-I and MHC-II Expression
title_full_unstemmed Comparing Effects of BK Virus Agnoprotein and Herpes Simplex-1 ICP47 on MHC-I and MHC-II Expression
title_short Comparing Effects of BK Virus Agnoprotein and Herpes Simplex-1 ICP47 on MHC-I and MHC-II Expression
title_sort comparing effects of bk virus agnoprotein and herpes simplex 1 icp47 on mhc i and mhc ii expression
url http://dx.doi.org/10.1155/2013/626823
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