In vitro characterization of the Meq proteins of Marek's disease virus vaccine strain CVI988

Dharani K. Ajithdoss, Sanjay M. Reddy, Paulette F. Suchodolski, Lucy F. Lee, Hsing Jien Kung, Blanca Lupiani

Research output: Contribution to journalArticle

20 Citations (Scopus)

Abstract

Gallid herpesvirus 2 (GaHV-2), commonly known as Marek's disease virus serotype-1 (MDV-1), causes T cell lymphomas in chickens. Vaccines prepared from the attenuated CVI988/Rispens MDV-1 strain currently offer the best protection. Although attenuated CVI988/Rispens is non-oncogenic, it codes for at least two forms of the MDV oncoprotein Meq, and these proteins (CVI-Meq and CVI-LMeq) have not been fully characterized. Here, we report that both CVI-Meq proteins, like the Meq protein of Md5 (a very virulent oncogenic strain), were capable of transforming Rat-2 and NIH3T3 cells. Both CVI-Meq and CVI-LMeq proteins activated the meq promoter only in the presence of chicken c-Jun (CK-Jun) whereas Md5-Meq activated the same promoter irrespective of CK-Jun co-expression. However, Meq proteins of both Md5 and CVI988 bound the meq promoter in a ChIP assay regardless of whether CK-Jun was co-expressed. To understand the role of Meq DNA binding and transactivation/repression domains in transcription, we constructed three chimeric Meq proteins, namely, Md5-CVI-Meq, CVI-Md5-Meq, and Md5-CVI-L by exchanging domains between Md5 meq and CVI meq genes. Although these chimeric Meq proteins, unlike CVI-Meq proteins, transactivated the meq promoter, the activation was significantly less than Md5-Meq. To determine the role of individual amino acids, point mutations were introduced corresponding to the amino acid changes of CVI-Meq into Md5-Meq. Amino acid residues at positions 71 and 320 of the Md5-Meq protein were found to be important for transactivation of the meq promoter. All three Meq proteins activated the MDV gB, MMP-3 and Bcl-2 promoters and suppressed transcription from the MDV pp38/pp14 bidirectional promoter. Although no significant differences were observed, decreased transactivation activity was observed with CVI-Meq proteins when compared to Md5-Meq. Collectively, the data presented here indicate that CVI-Meq proteins are generally weak transactivators, which might contribute to the non-oncogenic phenotype of CVI988 virus in chickens.

Original languageEnglish
Pages (from-to)57-67
Number of pages11
JournalVirus Research
Volume142
Issue number1-2
DOIs
Publication statusPublished - Jun 1 2009
Externally publishedYes

Fingerprint

Marek Disease Vaccines
Viruses
Gallid Herpesvirus 2
Proteins
Chickens
Transcriptional Activation
Amino Acids
In Vitro Techniques
Attenuated Vaccines
Trans-Activators
T-Cell Lymphoma
Oncogene Proteins
Matrix Metalloproteinases
Point Mutation

Keywords

  • b-ZIP protein
  • CVI988/Rispens
  • Marek's diseases virus
  • Meq
  • Oncoprotein
  • T cell lymphoma
  • Transactivation
  • Transformation
  • Vaccine

ASJC Scopus subject areas

  • Virology
  • Infectious Diseases
  • Cancer Research

Cite this

In vitro characterization of the Meq proteins of Marek's disease virus vaccine strain CVI988. / Ajithdoss, Dharani K.; Reddy, Sanjay M.; Suchodolski, Paulette F.; Lee, Lucy F.; Kung, Hsing Jien; Lupiani, Blanca.

In: Virus Research, Vol. 142, No. 1-2, 01.06.2009, p. 57-67.

Research output: Contribution to journalArticle

Ajithdoss, Dharani K. ; Reddy, Sanjay M. ; Suchodolski, Paulette F. ; Lee, Lucy F. ; Kung, Hsing Jien ; Lupiani, Blanca. / In vitro characterization of the Meq proteins of Marek's disease virus vaccine strain CVI988. In: Virus Research. 2009 ; Vol. 142, No. 1-2. pp. 57-67.
@article{ffb52f8e48924d74a915e3e1192e4c22,
title = "In vitro characterization of the Meq proteins of Marek's disease virus vaccine strain CVI988",
abstract = "Gallid herpesvirus 2 (GaHV-2), commonly known as Marek's disease virus serotype-1 (MDV-1), causes T cell lymphomas in chickens. Vaccines prepared from the attenuated CVI988/Rispens MDV-1 strain currently offer the best protection. Although attenuated CVI988/Rispens is non-oncogenic, it codes for at least two forms of the MDV oncoprotein Meq, and these proteins (CVI-Meq and CVI-LMeq) have not been fully characterized. Here, we report that both CVI-Meq proteins, like the Meq protein of Md5 (a very virulent oncogenic strain), were capable of transforming Rat-2 and NIH3T3 cells. Both CVI-Meq and CVI-LMeq proteins activated the meq promoter only in the presence of chicken c-Jun (CK-Jun) whereas Md5-Meq activated the same promoter irrespective of CK-Jun co-expression. However, Meq proteins of both Md5 and CVI988 bound the meq promoter in a ChIP assay regardless of whether CK-Jun was co-expressed. To understand the role of Meq DNA binding and transactivation/repression domains in transcription, we constructed three chimeric Meq proteins, namely, Md5-CVI-Meq, CVI-Md5-Meq, and Md5-CVI-L by exchanging domains between Md5 meq and CVI meq genes. Although these chimeric Meq proteins, unlike CVI-Meq proteins, transactivated the meq promoter, the activation was significantly less than Md5-Meq. To determine the role of individual amino acids, point mutations were introduced corresponding to the amino acid changes of CVI-Meq into Md5-Meq. Amino acid residues at positions 71 and 320 of the Md5-Meq protein were found to be important for transactivation of the meq promoter. All three Meq proteins activated the MDV gB, MMP-3 and Bcl-2 promoters and suppressed transcription from the MDV pp38/pp14 bidirectional promoter. Although no significant differences were observed, decreased transactivation activity was observed with CVI-Meq proteins when compared to Md5-Meq. Collectively, the data presented here indicate that CVI-Meq proteins are generally weak transactivators, which might contribute to the non-oncogenic phenotype of CVI988 virus in chickens.",
keywords = "b-ZIP protein, CVI988/Rispens, Marek's diseases virus, Meq, Oncoprotein, T cell lymphoma, Transactivation, Transformation, Vaccine",
author = "Ajithdoss, {Dharani K.} and Reddy, {Sanjay M.} and Suchodolski, {Paulette F.} and Lee, {Lucy F.} and Kung, {Hsing Jien} and Blanca Lupiani",
year = "2009",
month = "6",
day = "1",
doi = "10.1016/j.virusres.2009.01.008",
language = "English",
volume = "142",
pages = "57--67",
journal = "Virus Research",
issn = "0168-1702",
publisher = "Elsevier",
number = "1-2",

}

TY - JOUR

T1 - In vitro characterization of the Meq proteins of Marek's disease virus vaccine strain CVI988

AU - Ajithdoss, Dharani K.

AU - Reddy, Sanjay M.

AU - Suchodolski, Paulette F.

AU - Lee, Lucy F.

AU - Kung, Hsing Jien

AU - Lupiani, Blanca

PY - 2009/6/1

Y1 - 2009/6/1

N2 - Gallid herpesvirus 2 (GaHV-2), commonly known as Marek's disease virus serotype-1 (MDV-1), causes T cell lymphomas in chickens. Vaccines prepared from the attenuated CVI988/Rispens MDV-1 strain currently offer the best protection. Although attenuated CVI988/Rispens is non-oncogenic, it codes for at least two forms of the MDV oncoprotein Meq, and these proteins (CVI-Meq and CVI-LMeq) have not been fully characterized. Here, we report that both CVI-Meq proteins, like the Meq protein of Md5 (a very virulent oncogenic strain), were capable of transforming Rat-2 and NIH3T3 cells. Both CVI-Meq and CVI-LMeq proteins activated the meq promoter only in the presence of chicken c-Jun (CK-Jun) whereas Md5-Meq activated the same promoter irrespective of CK-Jun co-expression. However, Meq proteins of both Md5 and CVI988 bound the meq promoter in a ChIP assay regardless of whether CK-Jun was co-expressed. To understand the role of Meq DNA binding and transactivation/repression domains in transcription, we constructed three chimeric Meq proteins, namely, Md5-CVI-Meq, CVI-Md5-Meq, and Md5-CVI-L by exchanging domains between Md5 meq and CVI meq genes. Although these chimeric Meq proteins, unlike CVI-Meq proteins, transactivated the meq promoter, the activation was significantly less than Md5-Meq. To determine the role of individual amino acids, point mutations were introduced corresponding to the amino acid changes of CVI-Meq into Md5-Meq. Amino acid residues at positions 71 and 320 of the Md5-Meq protein were found to be important for transactivation of the meq promoter. All three Meq proteins activated the MDV gB, MMP-3 and Bcl-2 promoters and suppressed transcription from the MDV pp38/pp14 bidirectional promoter. Although no significant differences were observed, decreased transactivation activity was observed with CVI-Meq proteins when compared to Md5-Meq. Collectively, the data presented here indicate that CVI-Meq proteins are generally weak transactivators, which might contribute to the non-oncogenic phenotype of CVI988 virus in chickens.

AB - Gallid herpesvirus 2 (GaHV-2), commonly known as Marek's disease virus serotype-1 (MDV-1), causes T cell lymphomas in chickens. Vaccines prepared from the attenuated CVI988/Rispens MDV-1 strain currently offer the best protection. Although attenuated CVI988/Rispens is non-oncogenic, it codes for at least two forms of the MDV oncoprotein Meq, and these proteins (CVI-Meq and CVI-LMeq) have not been fully characterized. Here, we report that both CVI-Meq proteins, like the Meq protein of Md5 (a very virulent oncogenic strain), were capable of transforming Rat-2 and NIH3T3 cells. Both CVI-Meq and CVI-LMeq proteins activated the meq promoter only in the presence of chicken c-Jun (CK-Jun) whereas Md5-Meq activated the same promoter irrespective of CK-Jun co-expression. However, Meq proteins of both Md5 and CVI988 bound the meq promoter in a ChIP assay regardless of whether CK-Jun was co-expressed. To understand the role of Meq DNA binding and transactivation/repression domains in transcription, we constructed three chimeric Meq proteins, namely, Md5-CVI-Meq, CVI-Md5-Meq, and Md5-CVI-L by exchanging domains between Md5 meq and CVI meq genes. Although these chimeric Meq proteins, unlike CVI-Meq proteins, transactivated the meq promoter, the activation was significantly less than Md5-Meq. To determine the role of individual amino acids, point mutations were introduced corresponding to the amino acid changes of CVI-Meq into Md5-Meq. Amino acid residues at positions 71 and 320 of the Md5-Meq protein were found to be important for transactivation of the meq promoter. All three Meq proteins activated the MDV gB, MMP-3 and Bcl-2 promoters and suppressed transcription from the MDV pp38/pp14 bidirectional promoter. Although no significant differences were observed, decreased transactivation activity was observed with CVI-Meq proteins when compared to Md5-Meq. Collectively, the data presented here indicate that CVI-Meq proteins are generally weak transactivators, which might contribute to the non-oncogenic phenotype of CVI988 virus in chickens.

KW - b-ZIP protein

KW - CVI988/Rispens

KW - Marek's diseases virus

KW - Meq

KW - Oncoprotein

KW - T cell lymphoma

KW - Transactivation

KW - Transformation

KW - Vaccine

UR - http://www.scopus.com/inward/record.url?scp=67349229269&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=67349229269&partnerID=8YFLogxK

U2 - 10.1016/j.virusres.2009.01.008

DO - 10.1016/j.virusres.2009.01.008

M3 - Article

VL - 142

SP - 57

EP - 67

JO - Virus Research

JF - Virus Research

SN - 0168-1702

IS - 1-2

ER -