Use of a Fragment of Glycoprotein G-2 Produced in the Baculovirus Expression System for Detecting Herpes Simplex Virus Type 2-Specific Antibodies

摘要

Fragments of glycoprotein G (gG-2_281-594His), comprising residues 281 to 594 of herpes simplex virus type 2 (HSV-2), glycoprotein G of HSV-1 (gG-1_t26-189His), and glycoprotein D of HSV-1 (gD-1_1-313), were expressed in the baculovirus expression system to develop an assay for the detection of HSV-1 and HSV-2 type-specific antibodies. The expression of the gG-1_t26-189His and gG-2_281-594His fragments was analyzed by Western blotting using monoclonal antibodies LP10 and AP1, respectively. The molecular masses of the major products of gG-1_t26-189His and the fragment of gG-2_281-594His were 36 to 39 kDa and 64 to 72 kDa, respectively. Human sera positive for HSV-1 reacted with gG-1_t26-189His, sera positive for HSV-2 reacted with the gG-2_281-594His fragment, and sera positive for both types reacted with gG-1_t26-189His and gG-2_281-594His in Western blotting. The human sera recognized polypeptides of gG-2_281-594His with molecular masses of 57 to 67 and 120 to 150 kDa and additional faint bands of 21, 29, and 45 kDa. The recombinant gG-1_t26-189His and the recombinant gG-2_281-594His fragment were used as type-specific antigens for the detection of HSV-1- and HSV-2-specific antibody responses in human sera, respectively. As type-common antigens, an extract of HSV-1-infected Vero cells and recombinant gD-1_1-313 were used. An enzyme-linked immunosorbent assay to detect type-specific antibodies was developed, and the sensitivity and specificity were evaluated by comparison with commercial tests by using sera obtained from different sources. The sensitivity and specificity were 91.5 and 95.5%, respectively, compared to the Gull assay. The gG-2_281-594His fragment can be obtained in relatively large quantities at low cost.