TLR2 and infection: In addition to recognition of mycobacterial ligands, a role for TLR2 in recognizing the envelope (E) protein of SCV2 leading to innate viral control has been previously reported (68), and we show here that TLR2-deficient mice indeed displayed higher TCID50 viral titers in their lungs three days after infection with B.1.351 SCV2 in the absence of Mtb infection.