USE OF INVERSE POLYMERASE CHAIN-REACTION TO CHARACTERIZE A NOVEL HUMAN HERPESVIRUS-7 ISOLATE

Human herpesvirus-7 (HHV-7) is a T-lymphotropic virus detected in peri pheral blood mononuclear cells and in saliva, but no reliable link bet ween this agent and a disease has been demonstrated so far. Starting f rom a 186 bp-fragment described previously, we used an inverse polymer ase chain reaction to clone and sequence the adjacent sequences of thi s known region. A 1062 bp-fragment containing two ORFs was characteriz ed and its sequence was compared with those of two other beta-herpesvi ruses, human cytomegalovirus (HCMV) and human herpesvirus-6 (HHV-6). W ith respect to the first ORF, amino-acid identity was estimated to be 22% between HHV-7 and HCMV, and 47% between HHV-7 and HHV-6. In contra st, only a weak homology between HHV-7 and the two other P-herpesvirus es was demonstrated for the second ORF. The newly characterized 1062 b p-fragment was used to define a novel HHV-7-specific PCR assay. Prelim inary data indicate that this region is highly conserved among HHV-7 i solates. (C) 1997 Elsevier Science B.V.