Regions US6 and US7 of herpes simplex virus type 1 DNA encoding glycoproteins D and I may influence neuroinvasivity.

Recombinants were prepared by replacing a 1931 bp region of the BamHI J fragment (0.906-0.920) of the pathogenic ANGpath DNA-coding for glycoprotein D (gD) and a part of glycoprotein I (gI)--by the corresponding sequence of nonpathogenic KOS DNA (Kaerner et al., 1991) and tested in DBA/2 mice. The strain ANGpath and the control recombinant ANGpath/gD-gIpath, prepared by back transfer of the given ANGpath DNA fragment into ANGpath/gD-gIdellacZ+ DNA, were pathogenic after intraperitoneal inoculation. In contrast, mice infected with the strain KOS and the low-pathogenic recombinant ANGpath/gD-gIKOS survived peripheral virus administration. Both the strain KOS and the low-pathogenic recombinant ANDpath/gD-gIKOS spread by bloodstream to spleen, liver and adrenal glands but did not multiply in spinal cord. Nevertheless, the antigen of low-pathogenic recombinant ANGpath/gD-gIKOS was found in retroperitoneal vegetative nerves and ganglia. On the other hand, the strain ANGpath and the pathogenic recombinant ANGpath/gD-gIpath multiplied in cerebrospinal nerves and spinal cord causing typical hind leg paralysis.