[Genetics and susceptibility to human papillomaviruses: epidermodysplasia verruciformis, a disease model]

The outcomes of infection by human papillomaviruses (HPV), both oncogenic and non oncogenic, show major interindividual variability The underlying genetic factors and mechanisms are poorly known, but their complexity is illustrated by epidermodysplasia verruciformis (EV), a rare autosomal recessive genodermatosis associated with a high risk of non melanoma skin cancer. This model disease is characterized by abnormal susceptibility to widespread betapapillomaviruses, including HPV-5, a virus associated with EV cancers. Most cases of EV are caused by a mutation that inactivates either of two related genes, EVER1 and EVER2. This inactivation likely compensates for the absence of a viral gene (E5 or E8) essential for HPV pathogenicity. Proteins E5 and E8 interfere with the interaction between EVER proteins and ZnT1, a zinc transporter EV is thus likely to represent a primary defect of intrinsic (constitutive) immunity or innate immunity to betapapillomaviruses, involving modulation of zinc homeostasis upon keratinocyte infection. It remains to be established which cellular genes are involved in intrinsic, innate or acquired immune responses to other human papillomaviruses, including oncogenic genital types.