Advances in Human Polyomaviruses Field

Up to 2007, two human polyomaviruses BK (BKPyV) and JC (JCPyV) were known and named after the initials of the patients where they were first isolated. BKV was isolated from the urine of a kidney transplant patient affected by urethral stenosis [1]. JCV was identified in the brain tissue of a patient with Hodgkin lymphoma who developed a demyelinating disease known as progressive multifocal leukoencephalopathy [2]. After more than thirty years, thanks to the advances of molecular biology techniques, the number of newly uncovered human polyomaviruses increased rapidly. In 2007, the Karolinska Institute (KIPyV) and the Washington University (WUPyV) polyomaviruses were uncovered in the respiratory secretions of patients with acute respiratory symptoms by random PCR and high throughput sequencing [3,4]. Nine additional polyomaviruses were identified in the following years: Merckel cell polyomavirus (MCPyV) [5], human polyomaviruses 6 (HPyV6) and 7 (and HPyV7) [6], trichodysplasia spinulosa-associated polyomavirus (TSPyV) [7], human polyomavirus 9 (HPyV9) [8], human polyomavirus 10 (HPyV10)/Malawy polyomavirus (MWPyV)/Mexico polyomavirus (MXPyV) [9-11], human polyomavirus 12 [12], Saint-Louis polyomavirus (STLPyV) [13], New Jersey polyomavirus [14]. As for KIPyV and WUPyV molecular biology techniques were instrumental for their discovery.