THE RETROGRADE TRACER FLUOROGOLD INTERFERES WITH THE INFECTIVITY OF HERPES-SIMPLEX VIRUS

Fluoro-Gold has been used previously to identify those trigeminal gang lion cells that innervate the central cornea. To examine the effects o f Fluoro-Gold treatment on infection and spread of HSV in vivo, we mea sured the number of plaque forming units recovered from trigeminal gan glia 3 or 5 days after corneal scratch and inoculation with Fluoro-Gol d and HSV. Treatment with Fluoro-Gold reduced the amount of virus reco vered after retrograde transport 63% at 3 days and 28% at 5 days after inoculation. When we examined trigeminal ganglion sections from anima ls treated with HSV and Fluoro-Gold, we found the number of neurons do uble labeled with antibodies that recognize HSV and Fluoro-Gold was on ly 13% of all Fluoro-Gold labeled neurons. This was significantly fewe r cells that we had anticipated, on the basis of double labeling exper iments with wheat germ agglutinin combined with Fluoro-Gold. The effec ts of varying doses of the retrograde tracer, Fluoro-Gold on Herpes si mplex virus (type 1) (HSV) infectivity were also assayed in vitro usin g a standard viral plaque assay. At 1 X 10(-3) mg/ml Fluoro-Gold there was no effect on the number of plaque forming units. At 5 X 10(-1) mg /ml the number of plaques was reduced about 67%. We conclude that Fluo ro-Gold interferes with productive HSV infection in vivo and in vitro after retrograde transport of HSV by neurons.