Characterization of the immune response of cattle against non-cytopathic and cytopathic biotypes of bovine viral diarrhoea virus.

Abstract

Cross-infection studies of normal calves infected with homologous pairs of non-cytopathic and cytopathic bovine viral diarrhoea virus (BVDV) showed significant differences in both humoral and cellmediated immune responses against either biotype over a period of 5 months. Serological assays after primary intranasal inoculation showed striking significant (P 0n05) differences between biotypes. Neutralizing titres were detected earlier and were much higher with the non-cytopathic strain than with the homologous cytopathic strain. Significant biotype-specific differences were also observed in the lymphocyte proliferative responses of cattle following in vitro stimulation by non-cytopathic/ cytopathic BVDV and the non-structural p80 protein (NS3). The secondary immune response seems to be largely influenced by the biotype used for the primary inoculation and only to a lesser extent by the biotype inoculated for the second time after an

Experimental model of Border Disease Virus infection in lambs: comparative pathogenicity of pestiviruses isolated in France and Tunisia

“…There are many studies on the experimental reproduction of the Border Disease in cattle, sheep and pigs [4,5,11,14,16,25,28] with BVDV; there is, however, less information in the literature on the events associated with a postnatal infection of lambs with ovine pestiviruses [12,13,19].…”

Bovine viral diarrhoea virus induces apoptosis in blood mononuclear cells by a mechanism largely dependent on monocytes.

“…of 6n3 TCID &! per cell in complete RPMI 1640 medium as described previously (Lambot et al, 1997). A homologous pair of non-cytopathic and cytopathic strains, Pe515, obtained from a field case of mucosal disease (Brownlie et al, 1984), was used in this study.…”

“…A homologous pair of non-cytopathic and cytopathic strains, Pe515, obtained from a field case of mucosal disease (Brownlie et al, 1984), was used in this study. Viruses were multiplied onto calf testis (CT) cell cultures as described previously (Lambot et al, 1997). The supernatant from a non-infected CT cell preparation was used as control medium.…”

Evidence for biotype-specific effects of bovine viral diarrhoea virus on biological responses in acutely infected calves.

“…The inocula for the experiments were the homologous pair of ncp and cp biotypes of strain Pe515 originally isolated from a field case of MD (Brownlie et al, 1984). The procedure for the preparation of BVDV strain Pe515 biotypes was described previously (Lambot et al, 1997). Eighteen calves about 3 months old, free of both BVDV antigen and BVDV antibody, were randomly allotted into two groups of 7 (A and B) and one group of 4 (group C) animals in isolation units.…”

“…In order to gain further insight into the role of biotype in BVDV infection, the efficacy of biotype-specific responses in protecting animals against challenge was investigated. Ninety-one days after the first exposure, all calves were intranasally challenged with Pe515 ncp or cp according to the procedure described by Lambot et al (1997). Based on their inoculation histories, calves were divided into six subgroups : two subgroups in primary infection (named C1 and C2) and four subgroups in challenge (A1-2 and B1-2).…”