DEFECTIVE ENTRY OF HERPES-SIMPLEX VIRUS TYPE-1 AND TYPE-2 INTO PORCINE CELLS AND LACK OF INFECTION IN INFANT PIGS INDICATE SPECIES TROPISM

We have determined if a defect at entry of the human pathogen herpes s implex virus type 1 (HSV-1) into cultured porcine cells extends to HSV -2 and if the poor susceptibility of porcine cells for these viruses i s indicative of in vivo species tropism. HSV-1 replicates poorly in sw ine testis (ST) and other porcine cells which lack a functional non-he paran sulphate receptor(s) required for virus entry. By several criter ia, ST cells resist infection by either HSV-1 or HSV-2. Infection can be restored if normal entry is bypassed by PEG-mediated virion-cell me mbrane fusion. Neither HSV serotype infects, replicates or produces cl inical symptoms in infant pigs. No virus was isolated from any of mult iple sites and seroconversion did not occur. The in vitro defect in po rcine cells blocking HSV entry correlates with, and is likely to be at least partly responsible for, in vivo resistance of pigs to infection .