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Baculovirus PTP2 Functions as a Pro-Apoptotic Protein

The family Baculoviridae encompasses a large number of invertebrate viruses, mainly infecting caterpillars of the order Lepidoptera. The baculovirus Spodoptera exigua multiple nucleopolyhedrovirus (SeMNPV) induces physiological and behavioral changes in its host Spodoptera exigua, as well as immunol...

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Autores principales: Han, Yue, van Houte, Stineke, van Oers, Monique M., Ros, Vera I.D.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5923475/
https://www.ncbi.nlm.nih.gov/pubmed/29642442
http://dx.doi.org/10.3390/v10040181
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author Han, Yue
van Houte, Stineke
van Oers, Monique M.
Ros, Vera I.D.
author_facet Han, Yue
van Houte, Stineke
van Oers, Monique M.
Ros, Vera I.D.
author_sort Han, Yue
collection PubMed
description The family Baculoviridae encompasses a large number of invertebrate viruses, mainly infecting caterpillars of the order Lepidoptera. The baculovirus Spodoptera exigua multiple nucleopolyhedrovirus (SeMNPV) induces physiological and behavioral changes in its host Spodoptera exigua, as well as immunological responses, which may affect virus transmission. Here we show that the SeMNPV-encoded protein tyrosine phosphatase 2 (PTP2) induces mild apoptosis in Spodoptera frugiperda (Sf) 21 cells upon transient expression. Transient expression of a catalytic-site mutant of ptp2 did not lead to apoptosis, indicating that the phosphatase activity of PTP2 is needed to induce apoptosis. We also found that the caspase level (indicator of apoptosis) was higher in cells transfected with the ptp2 gene than in cells transfected with the catalytic mutant. Adding a caspase inhibitor reduced the level of ptp2-induced apoptosis. Moreover, deletion of the ptp2 gene from the viral genome prevented the induction of apoptosis in S. exigua hemocytes. The virus titer and virulence indices (the viral infectivity and the time to death) were not affected by deletion of the ptp2 gene. However, the viral occlusion body yield from S. exigua larvae infected with the mutant virus lacking the ptp2 gene was much lower than the yield from larvae infected with the wild-type (WT) virus. We hypothesize that the observed pro-apoptotic effects of PTP2 are the result of PTP2-mediated immune suppression in larvae, which consequently leads to higher viral occlusion body yields.
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spelling pubmed-59234752018-05-03 Baculovirus PTP2 Functions as a Pro-Apoptotic Protein Han, Yue van Houte, Stineke van Oers, Monique M. Ros, Vera I.D. Viruses Article The family Baculoviridae encompasses a large number of invertebrate viruses, mainly infecting caterpillars of the order Lepidoptera. The baculovirus Spodoptera exigua multiple nucleopolyhedrovirus (SeMNPV) induces physiological and behavioral changes in its host Spodoptera exigua, as well as immunological responses, which may affect virus transmission. Here we show that the SeMNPV-encoded protein tyrosine phosphatase 2 (PTP2) induces mild apoptosis in Spodoptera frugiperda (Sf) 21 cells upon transient expression. Transient expression of a catalytic-site mutant of ptp2 did not lead to apoptosis, indicating that the phosphatase activity of PTP2 is needed to induce apoptosis. We also found that the caspase level (indicator of apoptosis) was higher in cells transfected with the ptp2 gene than in cells transfected with the catalytic mutant. Adding a caspase inhibitor reduced the level of ptp2-induced apoptosis. Moreover, deletion of the ptp2 gene from the viral genome prevented the induction of apoptosis in S. exigua hemocytes. The virus titer and virulence indices (the viral infectivity and the time to death) were not affected by deletion of the ptp2 gene. However, the viral occlusion body yield from S. exigua larvae infected with the mutant virus lacking the ptp2 gene was much lower than the yield from larvae infected with the wild-type (WT) virus. We hypothesize that the observed pro-apoptotic effects of PTP2 are the result of PTP2-mediated immune suppression in larvae, which consequently leads to higher viral occlusion body yields. MDPI 2018-04-07 /pmc/articles/PMC5923475/ /pubmed/29642442 http://dx.doi.org/10.3390/v10040181 Text en © 2018 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Han, Yue
van Houte, Stineke
van Oers, Monique M.
Ros, Vera I.D.
Baculovirus PTP2 Functions as a Pro-Apoptotic Protein
title Baculovirus PTP2 Functions as a Pro-Apoptotic Protein
title_full Baculovirus PTP2 Functions as a Pro-Apoptotic Protein
title_fullStr Baculovirus PTP2 Functions as a Pro-Apoptotic Protein
title_full_unstemmed Baculovirus PTP2 Functions as a Pro-Apoptotic Protein
title_short Baculovirus PTP2 Functions as a Pro-Apoptotic Protein
title_sort baculovirus ptp2 functions as a pro-apoptotic protein
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5923475/
https://www.ncbi.nlm.nih.gov/pubmed/29642442
http://dx.doi.org/10.3390/v10040181
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