TLR3 and encephalitis: In relation to viral infections, Zhang et al. identified a dominant-negative TLR3 allele in patients with herpes simplex virus 1 (HSV-1) encephalitis[9], and Bell et al. found a heterozygous mutation (Phe554Ser) associated with impaired TLR3-dependent interferon induction in response to HSV-1[10].