Detection of the archetypal regulatory region of JC virus from the tonsil tissue of patients with tonsillitis and tonsilar hypertrophy

The regulatory regions of JC virus (JCV) DNAs in the brain of patients with progressive multifocal leukoencephalopathy (PML) ( designated as PML-type regulatory regions) are hypervariable, whereas those in the urine and renal tissue of individuals without PML have the same basic structure, designated as the archetype. It is thought that JCV strains with the archetypal regulatory region circulate in the human population. Nevertheless, Monaco et al (J Virol 70: 7004 - 7012, 1996) reported that PML-type regulatory regions occur in human tonsil tissue. The purpose of this study is to confirm their findings. Using nested polymerase chain reaction (PCR), the authors detected the regulatory region of JCV DNA in the tonsil tissue from 14 (44%) of 32 donors with tonsillitis and tonsilar hypertrophy. Sequencing of the detected regulatory regions indicated that they were identical with the archetypal regulatory regions detected previously or, in a few cases, slightly deviated from the archetype. This finding suggests not only that tonsil tissue is the potential site of initial JCV infection but also that archetypal JCV strains circulate in the human population.