SIGLEC1 and COVID-19: Immunofluorescent double staining of LNs from COVID-19 autopsies confirmed that the majority of SARS-CoV-2 NP antigen is found in ACE2+ cells, including CD68+ and CD169+ macrophages and CD11c+ DCs, whereas CD3+ T cells and B220+ B cells were negative for NP protein (Figure 4E), demonstrating that SARS-CoV-2 directly infects DCs and macrophages in spleens and LNs.