PRODUCTION OF A MONOCLONAL-ANTIBODY REACTED BROADLY WITH FELINE CALICIVIRUS FIELD ISOLATES

A monoclonal antibody (MAb) reactive with 36 field isolates and 2 labo ratory strains of feline calicivirus (FCV) was produced by immunizing mice with the mixture of FCVs. The MAb (4D7) reacted with FCVs in an e nzyme-linked immunosorbent assay (ELISA), but had no neutralizing acti vity against the F4 strain of FCV. MAb 8G1, previously produced agains t the FCV F4 strain, also reacted in ELISA with all FCVs used in the p resent study. However, the epitopes recognized by 4D7 and 8G1 were dif ferent. Using these two MAbs and a polyclonal rabbit antibody, we atte mpted to develop a sandwich ELISA for detection of FCV antigen. The co mbination of 4D7 and the polyclonal rabbit IgG was most sensitive. Usi ng this system, all the field isolates of FCV cultured in vitro were d etected. However, among the 36 swab samples, from which FCV was isolat ed, 4 were negative.