Preparation and in vitro evaluation of canine hyperimmune plasma against canine parvovirus: a strategy for passive immunotherapy

The aim of this study was to prepare anti-canine parvovirus hyperimmune plasma through repeated vaccination of dogs and to evaluate its neutralizing capacity and immunoreactivity against viral antigens in comparison with plasma from healthy and infected animals. Four healthy dogs were vaccinated four times at two-week intervals using a live attenuated CPV-۲ vaccine and hyperimmune plasma was collected. A CPV-۲b strain was isolated from fecal samples of clinically infected dogs and propagated in MDCK cells. Viral identity was confirmed by PCR targeting the VP۲ gene. Neutralizing antibody titers were determined using a virus neutralization assay, while CPV-specific antibody titers were measured by indirect ELISA. The immunogenicity against viral structural and non-structural proteins was assessed using Western blot analysis. Hyperimmune plasma exhibited the highest neutralizing titer (۱:۱۶۰±۶۴) compared with healthy (۱:۲۶ ± ۱۲) and infected (۱:۴.۵ ± ۲.۵) groups (p ≤ ۰.۰۱). ELISA optical density values were ۰.۶۳ ± ۰.۱۱, ۰.۵۰ ± ۰.۱۲, and ۰.۲۸±۰.۰۲ for hyperimmune, healthy, and infected plasma, respectively (p ≤ ۰.۰۰۱). Western blot analysis revealed the presence of reactive antibodies against VP۲ (۶۶.۰ ± ۷.۲), VP۱ (۳۰.۷ ± ۱۴.۳), VP۳ (۴۵.۰ ± ۵.۳), and NS۱ (۶۸.۰ ± ۷.۱) in the hyperimmune group, whereas only low levels of antibodies against VP۲ were detected in infected dogs. While antibodies against NS۱ were observed exclusively in the hyperimmune plasma. In conclusion, Canine hyperimmune plasma contains high-titer, polyclonal neutralizing antibodies against CPV. These in vitro findings support the probable effectiveness and its potential utility as an emergency passive immunotherapy for CPV infection.

کلیدواژه ها:

canine parvovirus ، hyperimmune plasma ، passive immunotherapy ، Dog