FcγR II B-mediated antibody-dependent enhancement of PRRSV infection

The positive serum against PRRSV Hn-1/06(virus-neutralizing antibody titers reached 1∶2)was diluted by a 1/2 dilution series method(2-8),then an equal volume of virus with a titer of 100 TCID50/100 μL was added to each dilution,infectious immune complexes was prepared.Purified swine IgG and rabbit anti-swine IgG were used to prepare for uninfectious immune complexes.Mouse anti FcγRⅡB serum was used to block PAM cells,then used infectious immune complexes and the mixture of uninfectious immune complexes with PRRSV to infect blocked PAM cells,after cultured for 48 h,collected samples,detected viral RNA copies of the samples by PRRSV fluorogenetic quantitative RT-PCR.The results indicated that selective blocking FcγRⅡB of PAM cells can enhance antibody-dependent enhancement of PRRSV infection.