Moreover, B18R, IFN-I neutralizing reagent, potently inhibited CD169 expression on infected and bystander MDMs (Fig. 1e and Supplementary Fig. 1k) and reduced IP-10 secretion (Fig. 1f), while, co-infection of vesicular stomatitis virus (VSV, whose infection is highly sensitive to IFN-I9) was inhibited in HIV-1-infected MDMs (Supplementary Fig. 1l, m), confirming the presence of bioactive IFN-I in the HIV-1-infected MDM culture supernatants. Here, SIGLEC1 is linked to coinfection.