NEUTRALIZING ANTIBODIES IN CATS INFECTED WITH FELINE IMMUNODEFICIENCYVIRUS

Sera from cats experimentally infected with five isolates of feline im munodeficiency vims (FIV) from various geographical regions and from F IV enzyme-linked immunosorbent assay-seropositive field cats from four European countries neutralized the Petaluma strain of FIV (FIV-P), or iginally isolated in California, at high titers. In addition, FIV-P an d a European isolate proved equally susceptible to neutralization by a ll sera tested. Coupled with observations by Fevereiro et al. (M. Feve reiro, C. Roneker, A. Laufs, L. Tavares, and F. de Noronha, J. Gen. Vi rol. 72:617-622, 1991), these findings indicate that most if not all F IV strains circulating in Europe and the United States share important neutralization-inducing epitopes.