TLR3 and infection: While freshly isolated B cells and DCs express little LLT1 mRNA, transcript levels are augmented following infection with viral pathogens (e.g., influenza, HSV-1, EBV, HIV) or TLR agonists (i.e., TLR-3, -4, -7, -8, -9), in particular CpG DNA treatment (91, 107).