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POSTER PRESENTATION Open Access Expression of ORF2 protein of TTV for development of EIA system Shiwani Singh * , M Ahmad Ansari, Akanksha Singh, Dhananjay Singh Mankotia, M Irshad From First International Science Symposium on HIV and Infectious Diseases (HIV SCIENCE 2012) Chennai, India. 20-22 January 2012 Background/aim Torque Teno Virus (TTV) is highly prevalent across the world. It is ssDNA virus having 4-5 ORFs of unknown function or antigenicity. To date 40 different genotypes of TTV have been detected. Present study is aimed to determine the antigenicity of ORF2 region of TTV genotype1. Methods ORF2 region of TTV genotype1 (JA20 isolate) was amplified using gene specific primers and cloned in pET19b expression vector for protein expression. Expressed protein was confirmed by western blotting using anti-His antibodies against N-terminal 6XHis tag of expressed protein. Antigenicity of ORF2 was deter- mined by western blot, detecting anti-TTV antibodies in 50 human sera of which, 10 were healthy control nega- tive for TTV-DNA, 10 liver disease cases negative for TTV-DNA and 30 liver disease cases that were positive for TTV-DNA. Results Protein of ORF2 region was successfully expressed and confirmed by western blotting. Anti-TTV antibodies were detected in 25 of 30 (83.3%) cases with liver dis- ease that were positive for TTV-DNA. All 10 cases of liver disease and 10 cases of healthy control, those were negative for TTV-DNA, remains negative for anti-TTV antibodies. Conclusion The results indicate that ORF2 protein is immunogenic, showing low detection of IgG. The reason could be that the protein expressed in this study by TTV genotype1 is producing genotype-specific immunity. However, the study indicates that the antibodies produced during TTV infection does not neutralize or cross-reacts. Further investigations are required to determine whether the protein can be used to develop assay for detection of genotype/genogroup of TTV-infection. Published: 4 May 2012 doi:10.1186/1471-2334-12-S1-P68 Cite this article as: Singh et al.: Expression of ORF2 protein of TTV for development of EIA system. BMC Infectious Diseases 2012 12(Suppl 1): P68. Submit your next manuscript to BioMed Central and take full advantage of: Convenient online submission Thorough peer review No space constraints or color figure charges Immediate publication on acceptance Inclusion in PubMed, CAS, Scopus and Google Scholar Research which is freely available for redistribution Submit your manuscript at www.biomedcentral.com/submit * Correspondence: [email protected] Dept. of Laboratory Medicine, All India Institute of Medical Sciences, Ansari Nagar, New Delhi-29, India Singh et al. BMC Infectious Diseases 2012, 12(Suppl 1):P68 http://www.biomedcentral.com/1471-2334/12/S1/P68 © 2012 Singh et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Expression of ORF2 protein of TTV for development of EIA system

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POSTER PRESENTATION Open Access

Expression of ORF2 protein of TTVfor development of EIA systemShiwani Singh*, M Ahmad Ansari, Akanksha Singh, Dhananjay Singh Mankotia, M Irshad

From First International Science Symposium on HIV and Infectious Diseases (HIV SCIENCE 2012)Chennai, India. 20-22 January 2012

Background/aimTorque Teno Virus (TTV) is highly prevalent across theworld. It is ssDNA virus having 4-5 ORFs of unknownfunction or antigenicity. To date 40 different genotypesof TTV have been detected. Present study is aimed todetermine the antigenicity of ORF2 region of TTVgenotype1.

MethodsORF2 region of TTV genotype1 (JA20 isolate) wasamplified using gene specific primers and cloned inpET19b expression vector for protein expression.Expressed protein was confirmed by western blottingusing anti-His antibodies against N-terminal 6XHis tagof expressed protein. Antigenicity of ORF2 was deter-mined by western blot, detecting anti-TTV antibodies in50 human sera of which, 10 were healthy control nega-tive for TTV-DNA, 10 liver disease cases negative forTTV-DNA and 30 liver disease cases that were positivefor TTV-DNA.

ResultsProtein of ORF2 region was successfully expressed andconfirmed by western blotting. Anti-TTV antibodieswere detected in 25 of 30 (83.3%) cases with liver dis-ease that were positive for TTV-DNA. All 10 cases ofliver disease and 10 cases of healthy control, those werenegative for TTV-DNA, remains negative for anti-TTVantibodies.

ConclusionThe results indicate that ORF2 protein is immunogenic,showing low detection of IgG. The reason could be thatthe protein expressed in this study by TTV genotype1 is

producing genotype-specific immunity. However, thestudy indicates that the antibodies produced duringTTV infection does not neutralize or cross-reacts.Further investigations are required to determine whetherthe protein can be used to develop assay for detection ofgenotype/genogroup of TTV-infection.

Published: 4 May 2012

doi:10.1186/1471-2334-12-S1-P68Cite this article as: Singh et al.: Expression of ORF2 protein of TTVfor development of EIA system. BMC Infectious Diseases 2012 12(Suppl 1):P68.

Submit your next manuscript to BioMed Centraland take full advantage of:

• Convenient online submission

• Thorough peer review

• No space constraints or color figure charges

• Immediate publication on acceptance

• Inclusion in PubMed, CAS, Scopus and Google Scholar

• Research which is freely available for redistribution

Submit your manuscript at www.biomedcentral.com/submit

* Correspondence: [email protected]. of Laboratory Medicine, All India Institute of Medical Sciences, AnsariNagar, New Delhi-29, India

Singh et al. BMC Infectious Diseases 2012, 12(Suppl 1):P68http://www.biomedcentral.com/1471-2334/12/S1/P68

© 2012 Singh et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative CommonsAttribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction inany medium, provided the original work is properly cited.