CCR2 and viral infectious disease: Since CCR2-dependent MCs poorly migrate to the dLN after AS01 injection and have inert APC functions in other systems when carefully separated from inf-cDC2s (23), the dependency of inf-cDC2s on CCR2 offers a more plausible explanation why Ccr2-/- mice have impaired Th1 cell-mediated responses after immunization with AS01-adjuvanted vaccine and increased susceptibility to viral infections (36, 43, 44).