Localization of viral DNA-replication in sections of human warts by nucleic acid hybridization with complementary RNA of human papilloma virus Type 1.

Using complementary RNA of human papilloma virus type 1 (HPV1) and in situ hybridization techniques the localization of viral DNA replication was studied in sections of 38 human virus acanthomata from 31 different patients. In five cases significant labeling was detected by autoradiography. Labeling started always in the first or the second suprabasal cell layer and was strongly limited to the nuclei. A remarkable early beginning of the vacuolated process seemed to be correlated with the visible DNA replication. No labeling could be detected in the basal cell layer. This suggests that these cells contain at the most only a small number of viral genomes. Our findings represent only the situation in human warts definitely caused by HPV 1. We are not able to say, whether our negative hybridization results in the remaining warts indicate either the scarcity of viral genomes within these sections or their infection by a different agent.