4
4. with well-defined antipolyomavirus activity (-)-Epicatechin gallate (23,37), the main treatment is reduction of immunosuppression at the expense of an increased risk of rejection (21). The active metabolite of the immunomodulatory drug leflunomide, A771726 (LEF-A), inhibitis mitochondrial dihydroorotate dehydrogenase (10), leading to pyrimidine depletion and cytostasis, particularly in activated lymphocytes (7). Tyrosine kinase (29), cyclooxygenase (18), and NF-B signaling (15) may also be affected at higher concentrations. Leflunomide has demonstrated antiviral (-)-Epicatechin gallate activity toward human immunodeficiency virus 1 (HIV-1) (38) and herpesviruses (25,44) and is now also used in treatment of PVAN (2,3,6,9,12,13,24,26,30,34,39,41,47), although its Rabbit polyclonal to TLE4 clinical efficacy has not been formally tested in controlled trials. For herpesviruses, the antiviral effect is attributed to impaired nucleocapsid tegumentation (25,44). Since BKV lacks tegument, the putative antiviral effect…