MONOCLONAL-ANTIBODY NEUTRALIZATION OF BPV-1

Mouse monoclonal antibodies were generated against intact infectious B PV-1 virions by methods previously described (Christensen et al., 1990 ). ELISA was used to screen for reactivities to intact and/or disrupte d BPV-1, CRPV and HPV-11 virions. Several hybridomas were initially se lected that showed antibody reactivity by ELISA to both intact and dis rupted BPV-1, to disrupted BPV-1 only, or to intact BPV-1 virions. One monoclonal antibody, designated B1.Al, which reacted only to intact B PV-1 was selected for virus neutralization analyses. ELISA demonstrate d that this monoclonal antibody bound to intact BPV-1 virions, but not to intact CRPV, HPV-11 or to disrupted papillomavirus (PV) antigens. Strong neutralization of BPV-1-induced focus formation of mouse C127 c ells by monoclonal Bl.Al was observed. The neutralization titer was eq uivalent to the neutralization titer obtained with a polyclonal rabbit anti-BPV-1 virion antisera, and directly correlated with antibody con centration as determined by ELISA. These results extend our previous a nalyses on the epitopes of infectious papillomaviruses as defined by m onoclonal antibodies that identify neutralizing epitopes. The nature o f these epitopes is such that maintenance of the quaternary structure of the infectious virions is necessary for preservation of the antigen icity of the neutralizing epitope.