CHEMICAL INACTIVATION OF RECOMBINANT VACCINIA VIRUSES AND THE EFFECTSON ANTIGENICITY AND IMMUNOGENICITY OF RECOMBINANT SIMIAN IMMUNODEFICIENCY VIRUS ENVELOPE GLYCOPROTEINS

The efficiency of paraformaldehyde (PFA) and binary ethylenimine (BEI) in inactivating recombinant vaccinia virus (rVV), present in baby ham ster-kidney cells expressing simian immunodeficiency virus envelope gl ycoproteins (SIV-Env), was measured in a series of inactivation studie s. Both compounds were shown to be effective in reducing rVV titres, T he use of standard 3-day titration assays proved to be inadequate to m easure PFA inactivation since upon prolonged incubation residual rVV i nfectivity was detected in cultures negative at 3 days. Different proc edures using PFA or BEI were selected to assess their influence on the antigenicity and immunogenicity of rVV expressed SIV-Env, Antigenicit y, as defined by the ability to react with a panel of monoclonal antib odies recognizing major antigenic sites, and immunogenicity, as define d by the ability to induce SIV envelope specific and virus neutralizin g serum antibodies in rats, proved to be preserved after either inacti vation procedure, These data show that both protocols using PFA or-BEI can be used successfully as part of the procedures to remove residual rVV infectivity. (C) 1997 Elsevier Science Ltd.