This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Jääskeläinen, A. Articles by Vapalahti, O. Search for Related Content PubMed PubMed Citation Articles by Jääskeläinen, A. Articles by Vapalahti, O.

 Previous Article  |  Next Article 

Journal of Clinical Microbiology, September 2003, p. 4336-4342, Vol. 41, No. 9
0095-1137/03/$08.00+0     DOI: 10.1128/JCM.41.9.4336-4342.2003
Copyright © 2003, American Society for Microbiology. All Rights Reserved.

Diagnosis of Tick-Borne Encephalitis by a µ-Capture Immunoglobulin M-Enzyme Immunoassay Based on Secreted Recombinant Antigen Produced in Insect Cells

Anu Jääskeläinen,^1* Xiuqi Han,¹ Matthias Niedrig,² Antti Vaheri,^1,3 and Olli Vapalahti^1,3,4

Department of Virology, Haartman Institute,¹ Division of Microbiology and Epidemiology, Faculty of Veterinary Medicine, FIN-00014 University of Helsinki,⁴ Department of Virology, Helsinki University Central Hospital Laboratory Diagnostics, FIN-00029 HUS, Finland,³ Robert Koch Institute, 13353 Berlin, Germany²

Received 23 September 2002/ Returned for modification 3 March 2003/ Accepted 20 May 2003

Acute tick-borne encephalitis is diagnosed by detection of IgM antibodies to tick-borne encephalitis virus (TBEV) (genus Flavivirus) in patient serum. TBEV membrane (M) and envelope (E) proteins have previously been shown to form virus-like particles when expressed in mammalian cells. We expressed the prM/M and E proteins in insect cells with a recombinant baculovirus system and obtained antigenic protein secreted into the cell culture medium, as evidenced by detection by a panel of five monoclonal antibodies to TBEV E protein. According to the sedimentation pattern in sucrose gradient centrifugation, the proteins were most likely secreted as virus-like particles. A µ-capture immunoglobulin M-enzyme immunoassay (IgM-EIA) test was developed and compared to a commercially available TBEV-IgM test (Progen) based on inactivated purified TBEVs. With a panel of 100 TBEV-IgM-negative, 50 TBEV-IgM-positive, and seven dengue virus-IgM-positive serum samples from our diagnostic laboratory, a sensitivity of 100% and specificity of 99% were obtained, and the correlation coefficient of EIA absorbances with the reference test was 0.93. The antigen was also suitable for IgG antibody detection in an immunofluorescent assay format. This is the first time that secreted, fully antigenic E protein has been produced in insect cells for this arthropod-borne flavivirus.

---

* Corresponding author. Mailing address: Department of Virology, Haartman Institute, POB 21, FIN-00014 University of Helsinki, Finland. Phone: 358 9 191 26 487. Fax: 358 9 191 26 491. E-mail: anu.jaaskelainen{at}helsinki.fi.

---

Journal of Clinical Microbiology, September 2003, p. 4336-4342, Vol. 41, No. 9
0095-1137/03/$08.00+0     DOI: 10.1128/JCM.41.9.4336-4342.2003
Copyright © 2003, American Society for Microbiology. All Rights Reserved.

This article has been cited by other articles:

• Marjelund, S., Jaaskelainen, A., Tikkakoski, T., Tuisku, S., Vapalahti, O. (2006). Gadolinium Enhancement of Cauda Equina: A New MR Imaging Finding in the Radiculitic Form of Tick-Borne Encephalitis.. Am. J. Neuroradiol. 27: 995-997 [Abstract] [Full Text]  
• Ishiguro, N., Ebihara, T., Endo, R., Ma, X., Shirotsuki, R., Ochiai, S., Ishiko, H., Kikuta, H. (2005). Immunofluorescence Assay for Detection of Human Metapneumovirus-Specific Antibodies by Use of Baculovirus-Expressed Fusion Protein. CVI 12: 202-205 [Abstract] [Full Text]