RECRUDESCENCE OF HERPES-SIMPLEX VIRUS TYPE-1 IN LATENTLY INFECTED-RATS AFTER TRAUMA TO ORAL-TISSUES

Tooth extraction in rats was used to trigger a latent HSV-1 infection. HSV-1 was inoculated unilaterally in the rat palates. Eight weeks lat er two molars were removed bilaterally. The trigeminal ganglia were co -cultivated and HSV-1 was isolated from 63% of the ganglia on the infe cted sides but from only 11% on control sides. The immune response pat tern was analysed by immunoblotting of rat serum, and strong reactivit y to HSV-1 specific cell polypeptides and glycoproteins (ICP6, gC, pgC , gD) was seen after reactivation. The extraction sockets were histopa thologically evaluated and showed healing on the infected side in 26% compared to 63% in contralateral control sockets. The effect of acyclo vir (ACV) treatment was elucidated and was found to influence the subs equent development of antibodies and to promote healing of the sockets . Vesiculation in intra- and subepithelial tissue was present on the i nfected side in 58% but in only 12% of ACV-treated animals. The presen t study in rats has shown that a latent HSV-1 infection can be establi shed and reactivated by tooth extraction. Reactivation resulted in del ayed healing of sockets on the latently infected side but not on the c ontralateral control side. HSV-1 reactivation was demonstrated serolog ically by immunoblotting. Healing was significantly promoted by admini stration of ACV, which also supports the contention that HSV-1 interfe res with the healing process.