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. 2011;6(8):e23023.
doi: 10.1371/journal.pone.0023023. Epub 2011 Aug 9.

Vesicular stomatitis virus infection promotes immune evasion by preventing NKG2D-ligand surface expression

Helle Jensen  1 , Lars Andresen, Jens Nielsen, Jan Pravsgaard Christensen, Søren Skov
Affiliations

Vesicular stomatitis virus infection promotes immune evasion by preventing NKG2D-ligand surface expression

Helle Jensen et al. PLoS One. 2011.

Abstract

Vesicular stomatitis virus (VSV) has recently gained attention for its oncolytic ability in cancer treatment. Initially, we hypothesized that VSV infection could increase immune recognition of cancer cells through induction of the immune stimulatory NKG2D-ligands. Here we show that VSV infection leads to a robust induction of MICA mRNA expression, however the subsequent surface expression is potently hindered. Thus, VSV lines up with human cytomegalovirus (HCMV) and adenovirus, which actively subvert the immune system by negatively affecting NKG2D-ligand surface expression. VSV infection caused an active suppression of NKG2D-ligand surface expression, affecting both endogenous and histone deacetylase (HDAC)-inhibitor induced MICA, MICB and ULBP-2 expression. The classical immune escape mechanism of VSV (i.e., the M protein blockade of nucleocytoplasmic mRNA transport) was not involved, as the VSV mutant strain, VSV(ΔM51), which possess a defective M protein, prevented MICA surface expression similarly to wild-type VSV. The VSV mediated down modulation of NKG2D-ligand expression did not involve apoptosis. Constitutive expression of MICA bypassed the escape mechanism, suggesting that VSV affect NKG2D-ligand expression at an early post-transcriptional level. Our results show that VSV possess an escape mechanism, which could affect the immune recognition of VSV infected cancer cells. This may also have implications for immune recognition of cancer cells after combined treatment with VSV and chemotherapeutic drugs.

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Conflict of interest statement

Competing Interests: The authors have declared that no competing interests exist.

Figures

Figure 1
Figure 1. Surface expression of NKG2D ligands is down modulated upon VSV infection.
A, JE6-1 cells were either mock infected+non-treated with FR901228 (-), mock infected+treated with 20 ng/ml FR901228 for 18 hr (FR) or infected with the indicated MOI of VSV10 for 19 hr. The MICA mRNA level was examined by real-time RT-PCR and surface expression of MICA/B by flow cytometry. The MICA mRNA level is displayed as fold expression relative to the mock infected sample. The bar graphs show mean±SD from four experiments. B, JE6-1 cells were either treated with 20 ng/ml FR901228 or infected with 0.1 MOI VSV10 for 0, 4, 8, 12, 15 or 18 hr. The MICA mRNA level was examined by real-time RT-PCR. The MICA mRNA level is displayed as fold expression relative to the mock treated/infected sample. The bar graphs show mean±SD from two experiments. C and D, JE6-1 cells were mock infected (-) or infected with the indicated MOI of VSV10 one hr prior to treatment with 20 ng/mL FR901228. 19 hr post infection, the cells were analyzed for MICA/B or ULBP-2 surface expression or intracellular MICA/B expression by flow cytometry. The bar graphs show mean±SD from three experiments. E, The melanoma cell lines, FM-86 and FM-78, were mock infected (-) or infected with 0.1 MOI VSV10 for 19 hr and analysed for MICA/B surface expression by flow cytometry. The bar graphs show mean±SD from two experiments. For all the bar graphs, ** p<0.05 and *** p<0.0001.
Figure 2
Figure 2. Interferon-α restores FR901228-induced MICA/B surface expression after VSV infection.
JE6-1 cells were treated twice with 1000 U IFN-α with a 24 hr interval. One hr after the second treatment with IFN-α, the cells were mock infected or infected with 0.01 MOI VSV10. One hr post infection the cells were treated with 20 ng/mL FR901228 (FR), where indicated. 19 hr post infection, the cells were analyzed for MICA/B surface expression by flow cytometry. The data represent one out of two experiments.
Figure 3
Figure 3. Infection with the M protein mutated virus strain, VSVΔM51, blocks NKG2D-ligand surface expression.
A, JE6-1 cells were either mock infected+non-treated with FR901228 (-), mock infected+treated with 20 ng/ml FR901228 for 18 hr (FR) or infected with the indicated MOI of VSVΔM51 for 19 hr. The MICA mRNA level was examined by real-time RT-PCR and surface expression of MICA/B by flow cytometry. The MICA mRNA level is displayed as fold expression relative to the mock infected sample. The bar graphs show mean±SD from four and three experiments, respectively. B and C, JE6-1 cells were mock infected (-) or infected with the indicated MOI of VSVΔM51 one hr prior to treatment with 20 ng/mL FR901228. 19 hr post infection, the cells were analyzed for MICA/B or ULBP-2 surface expression or intracellular MICA/B expression by flow cytometry. The bar graphs show mean±SD from three experiments. D, The melanoma cell lines, FM-86 and FM-78, were mock infected (-) or infected with 0.1 MOI VSVΔM51 for 19 hr and analysed for MICA/B surface expression by flow cytometry. The bar graphs show mean±SD from two experiments. E, The VSVΔM51 M protein was sequenced as described in section 2.7. The VSVΔM51 clone insert was aligned to the gene bank sequence of M protein (VSV WT; M11754.1; Indiana serotype of VSV). For all the bar graphs, * p<0.05 and *** p<0.0001.
Figure 4
Figure 4. VSV-mediated down modulation of MICA/B surface expression is not caused by apoptosis.
JE6-1 cells were incubated with 50 µM ZVAD-Fmk (ZVAD) just prior to mock infection (-) or infection with 0.01 MOI VSV10 or VSVΔM51. One hr post infection, the cells were treated with 20 ng/mL FR901228 (FR), where indicated. 19 hr post infection, the cells were analyzed for MICA/B surface expression by flow cytometry. The bar graphs show mean±SD from three experiments. *** p<0.0001.
Figure 5
Figure 5. VSV-mediated inhibition of MICA surface expression occurs at an early post transcriptional level.
A, JTag-9 cells were transiently transfected with 5 µg MICA*008-GFP (MICA*008) or MICA*009-GFP (MICA*009) vector constructs. Two hr post transfection, the cells were either mock infected or infected with 0.001 MOI VSV10 for 19 hr. The cells were analyzed for surface MICA/B expression by flow cytometry. The dot-plots represent one out of three experiments. B, JTag-9 cells were transiently transfected as described in A. Two hr post transfection, the cells were either mock infected (-) or infected with 0.001 or 0.01 MOI VSVΔM51 for 19 hr. The cells were analyzed for MICA/B surface expression by flow cytometry. The bar graphs show mean±SD from three experiments.
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References

    1. Stojdl DF, Lichty B, Knowles S, Marius R, Atkins H, et al. Exploiting tumor-specific defects in the interferon pathway with a previously unknown oncolytic virus. Nat Med. 2000;6:821–825. - PubMed
    1. Balachandran S, Porosnicu M, Barber GN. Oncolytic activity of vesicular stomatitis virus is effective against tumors exhibiting aberrant p53, Ras, or myc function and involves the induction of apoptosis. J Virol. 2001;75:3474–3479. - PMC - PubMed
    1. Lichty BD, Power AT, Stojdl DF, Bell JC. Vesicular stomatitis virus: re-inventing the bullet. Trends Mol Med. 2004;10:210–216. - PubMed
    1. Clinton GM, Little SP, Hagen FS, Huang AS. The matrix (M) protein of vesicular stomatitis virus regulates transcription. Cell. 1978;15:1455–1462. - PubMed
    1. Jayakar HR, Murti KG, Whitt MA. Mutations in the PPPY motif of vesicular stomatitis virus matrix protein reduce virus budding by inhibiting a late step in virion release. J Virol. 2000;74:9818–9827. - PMC - PubMed

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