CD4 and infection: In mDCs, CLRs are downregulated while the I-type lectin CD169/Siglec-1 is highly upregulated and was shown to be involved in HIV-1 uptake and subsequent cis- and trans-infection of CD4+ T cell through interaction with a-2,3-linked sialic acid residues on the glycosphingolipid GM3 (host cell-derived glycosphingolipid that is incorporated in HIV-1 virions) (Puryear et al., 2013; Akiyama et al., 2017).