HERV-E expression in peripheral mononuclear cells of patient with Psoriasis.

BACKGROUND Psoriasis is a common inflammatory skin disease characterized by uncontrolled proliferation of keratinocytes and recruitment of T lymphocytes into the skin. Possible triggers for psoriasis have been attributed to drugs or pathogens such as bacteria and possibly virus. Human endogenous retroviruses (HERVs) might play a role in triggering these anti-viral immune responses, since the role of HERVs in the pathogenesis of autoimmune diseases has generated considerable interest. Some studies have also reported an association of HERV-E and psoriasis. None of them investigate the HERV-E expression in peripheral blood of psoriasis. All these considerations have prompted us to perform a survey for HERV-E expression in PBMC from psoriatic patients. METHODS Peripheral blood mononuclear cells from 69 psoriatic patients were analyzed. Total RNA was extracted and amplified with reverse transcription polymerase chain reaction. Results were compared with those obtained in a cohort of 20 healthy donors. RESULTS HERV E was expressed in all samples analyzed but the level of expression was much lower in the psoriasis that in HC p<0.0001. CONCLUSIONS The reasons for the unexpected, low levels of HERV expression in psoriatic patients are unclear and might be in part a consequence of anti-viral defense mechanisms.