EFFECT OF SPECIFIC ANTIBODIES ON THE CELL-ASSOCIATED SPREAD OF PSEUDORABIES VIRUS IN MONOLAYERS OF DIFFERENT CELL-TYPES

The effect of specific pseudorabies virus (PRV) antibodies on the enla rgement of plaques produced by PRV were studied in monolayers of diffe rent cell types. The plaque size was used as parameter for the efficac y of the cell-associated spread (CAS) of PRV. First, the effect of ant i-PRV hyperimmune serum on the plaque growth was examined in monolayer s of the continuous cell lines ST, SK-6 and MDCK and monolayers of the primary cultures of porcine fibroblasts, endothelial cells and endome trial cells. A tenfold increase in the serum concentration did reduce the plaque size with 50% in both SK-cells and fibroblasts and with 40, 28 and 16% in MDCK, endothelial and endometrial cells, respectively. In ST cells, no change in size was observed with increasing antibody c oncentrations. Secondly, the effects of monoclonal antibodies (mAbs) d irected against PRV glycoproteins gB, gC, gD and gE and polyclonal ant ibodies against gC were evaluated in SK-6 cells. MAbs against gB, go a nd gE were able to reduce the CAS with a cumulative effect between mAb s against go and either mAbs against gB or mAbs against gE. Monoclonal and polyclonal antibodies against gC did not change the plaque size.