CHARACTERIZATION OF NEUTRALIZING DOMAINS ON VARICELLA-ZOSTER VIRUS GLYCOPROTEIN-E DEFINED BY MONOCLONAL-ANTIBODIES

The genome of varicella-zoster virus (VZV), encodes at least six glyco proteins and they elicit the formation of complement-independent, comp lement-dependent, and non-neutralizing antibody responses. We have use d our library of MAbs to VZV glycoprotein E (gE) to determine the neut ralizing epitopes of gE, and shown that gE has 3 distinct neutralizing domains. In this report we have used the baculovirus expression syste m to identify the antigenic domains of gE. We have generated 3 recombi nant baculoviruses, expressing the full-length gE and two overlapping truncated forms (the amino-terminal and the carboxy-terminal) of gE. B y immune-fluorescence and immunoblotting we have explored the physical interactions of Mabs to gE on these constructs. Our panel of MAbs rev ealed 3 district antigenic domains on gE. All MAbs reacted with the fu ll-length gE; MAbs with high titered complement-dependent neutralizing activities reacted with the N-terminal truncated gE; MAbs with low ti tered or non-neutralizing activities reacted with the C-terminal trunc ated gE; MAbs with complement-enhanced neutralizing activities reacted with both truncated constructs. However, although the antibody bindin g in immunofluorescence and immunoblotting was carried out under denat ured conditions, whereas the neutralization is under non-denatured con ditions, still the antigenic mapping was similar in both conditions.