Combination of Epstein-Barr virus scaffold (BdRF1/VCA-p40) and small capsid protein (BFRF3/VCA-p18) into a single molecule for improved serodiagnosis of acute and malignant EBV-driven disease.
Current single Epstein-Barr virus (EBV) markers fail to reach 100% sensitivity for serodiagnosis of acute and malignant diseases associated with EBV infection. Previous study had identified immunodominant epitopes of VCA-p40 and VCA-p18, and indicated that these two VCA antigens may have diagnostic value for EBV-related diseases. A recombinant protein of the full-length BdRF1 fused to the immunodominant domain of BFRF3 as 6-his tagged protein in Escherichia coli was developed. The recombinant protein was extracted in 8M urea solution and purified by metal-affinity chromatography yielding a 55 kDa product (VCA-p40+18). VCA-p40+18 blot-strips examined for IgM reactivity in infectious mononucleosis samples yielded 100% sensitivity and specificity, with improved reactivity compared with IgM/VCA-p18-ELISAs. A recent study described a synthetic peptide-based IgA/[EBNA1+VCA-p18]-ELISA (IgA/EBV-ELISA), with a sensitivity of 90% for diagnosing nasopharyngeal carcinoma. Immunoblot analysis of biopsy-confirmed nasopharyngeal carcinoma cases with low or negative IgA/EBV-ELISA showed 100% IgG reactivity to VCA-p40 and VCA-p18 proteins. Evaluation of VCA-p40+18 as an additional marker for screening and diagnosis of nasopharyngeal carcinoma was carried out. The data showed positive IgA/VCA-p40+18 reactivity by ELISA for 63.6% (14 of 22) nasopharyngeal carcinoma samples that were missed by peptide-based IgA/EBV-ELISA, suggested VCA-p40+18 as an improved marker for nasopharyngeal carcinoma serodiagnosis. The VCA-p40+18 may be combined with an EBNA1 synthetic peptide as an antigen mixture in one or separate IgA ELISA for improved nasopharyngeal carcinoma serodiagnosis.
Fachiroh
Jajah
J
Molecular Biology Laboratory, Faculty of Medicine, Gadjah Mada University, Sekip, Yogyakarta, Indonesia. jajahfachiroh@indosat.net.id
Stevens
Servi J C
SJ
Haryana
Sofia M
SM
Middeldorp
Jaap M
JM
D000914:Antibodies, Viral / Q000097:blood*; D000956:Antigens, Viral / Q000235:genetics / Q000276:immunology; D001706:Biopsy; D015153:Blotting, Western; D036022:Capsid Proteins / Q000235:genetics / Q000276:immunology; D002277:Carcinoma; D002846:Chromatography, Affinity; D020031:Epstein-Barr Virus Infections / Q000175:diagnosis*; D004926:Escherichia coli / Q000235:genetics; D004854:Herpesvirus 4, Human / Q000235:genetics / Q000276:immunology*; D006801:Humans; D007075:Immunoglobulin M / Q000097:blood; D007244:Infectious Mononucleosis / Q000175:diagnosis / Q000821:virology; D008970:Molecular Weight; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000175:diagnosis / Q000821:virology; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D012680:Sensitivity and Specificity; D012698:Serologic Tests / Q000379:methods; D014773:Virology / Q000379:methods*
D000914:Antibodies, Viral; D000956:Antigens, Viral; D036022:Capsid Proteins; C041788:Epstein-Barr viral capsid antigen; D007075:Immunoglobulin M; D011993:Recombinant Fusion Proteins