CROSS VIRUS NEUTRALIZING ANTIBODIES AGAINST FELINE IMMUNODEFICIENCY VIRUS GENOTYPE-A, GENOTYPE-B, GENOTYPE-C, GENOTYPE-D AND GENOTYPE-E

Feline immunodeficiency virus (FIV) is classified into five genotypes, A, B, C, D and E, based on the phylogenetic analysis of the env V3-V5 region. However, whether there is correlation between phylogenetic an d antigenic diversities remains unknown. In this study, we examined th e cross virus neutralization of RV genotypes A through E by sera from cats infected with a single genotype. The results indicated some relat ionships between phylogenetic genotype and neutralization serotype, an d that cross-clade virus neutralization is possible. For example, seru m from a cat infected with genotype E virus neutralized all five FIV g enotypes. Our results suggest that the FIV subtyping according to the sequence diversity is partially reflected by antigenic diversity and s erum neutralization.