title: Immunogenicity of enterovirus 70 capsid protein VP1 and its non-overlapping N- and C-terminal fragments.
abstract: Currently no practical treatment method or effective virus vaccine is available for acute hemorrhagic conjunctivitis (AHC) caused by enterovirus 70 (EV70). Antibodies to UV-inactivated EV70 (J670/71 epidemic isolate) and to the inclusion bodies of recombinant proteins of full-length EV70 VP1 (GST-VP1m), its non-overlapping terminal fragments N138 (1-138 aa) and C170 (141-310 aa) (or GST-N138m and GST-C170) were developed in rabbits. The anti-EV70 neutralizing activities of the rabbit sera were determined by standard neutralization assays. The antibodies to UV-inactivated EV70, were immuno-reactive with EV70 capsid proteins VP1 and VP3 of four EV70 epidemic isolates (KW/97, T260/74, J670/71 and AE/72) in Western-blot analysis, and immunoprecipitated the capsid proteins VP1 and VP3 from the cell lysates of virus-infected human Chang's conjunctival (HCC) cells. The antibodies to GST-VP1m, GST-N138m and GST-C170, immunoprecipitated only the VP1 proteins of the four EV70 isolates. Anti-EV70 J670/71 antibodies and the antibodies to the three recombinant VP1 proteins were all capable of immunoprecipitating EV70 whole-virus of the four EV70 epidemic isolates grown in HCC cells. The anti-EV70 virion antibodies neutralized EV70 isolates with titers of 6000-10,000 units/ml while the antibodies to GST-VP1m, GST-N138m or GST-C170 neutralized EV70 isolates with titers of 20-320units/ml. The results suggest that (a) immunization with bacterially produced recombinant EV70 VP1 and its non-overlapping N- and C-terminal fragments, was capable of eliciting EV70-neutralizing antibodies; (b) the neutralization titers of antibodies to the recombinant VP1 proteins were lower than that of antibodies to the UV-inactivated EV70 virions; and (c) the non-overlapping N138 and C170 fragments of EV70 VP1 both harbor independent anti-EV70 neutralization antigenic sites.
authors.affiliation: Department of Ophthalmology, Louisiana State University Health Sciences Center, Shreveport, LA 71130-3932, USA. dchen@lsuhsc.edu
authors.forename: Dequan
authors.initials: D
authors.lastname: Chen
authors.forename: Chris
authors.initials: C
authors.lastname: Duggan
authors.forename: Donald E
authors.initials: DE
authors.lastname: Texada
authors.forename: Thomas B
authors.initials: TB
authors.lastname: Reden
authors.forename: Lakshmana M
authors.initials: LM
authors.lastname: Kooragayala
authors.forename: Marlyn P
authors.initials: MP
authors.lastname: Langford
mesh_terms: D000914:Antibodies, Viral / Q000032:analysis*; D000917:Antibody Formation; D036022:Capsid Proteins / Q000737:chemistry / Q000276:immunology*; D002460:Cell Line; D030016:Enterovirus D, Human / Q000276:immunology*; D004769:Enterovirus Infections / Q000276:immunology*; D004847:Epithelial Cells / Q000187:drug effects / Q000821:virology; D006801:Humans; D010446:Peptide Fragments / Q000276:immunology
chemical_list: D000914:Antibodies, Viral; D036022:Capsid Proteins; D010446:Peptide Fragments