Isolation and Purification of Immune Cells

Whole blood, lymph node, and bone marrow samples were processed as previously described (40 (link)). Briefly, peripheral blood mononuclear cells (PBMCs) were isolated from whole blood by density gradient centrifugation using Ficoll-Paque PLUS (Cytiva) and centrifuged at 1,860 x g for 30 minutes. Plasma was saved for viral nucleic acid and Leronlimab concentration detection. Buffy coat containing PBMCs was collected and washed with R10 (RPMI 1640 containing 10% fetal bovine serum (FBS)) before use. Lymph nodes were collected in R10, diced with a scalpel, and forced through a 70 μm cell strainer to a single cell suspension in R10. Bone marrow aspirates were collected in R10 and pelleted by centrifugation at 830 x g for 4 minutes. Cell pellets were resuspended by shaking in PBS containing 2 mM EDTA, and then centrifuged at 830 x g for 4 minutes. Cell pellets were then resuspended in 70% isotonic Percoll (GE Healthcare, Buckinghamshire, UK) and layered under 37% isotonic Percoll. Layers were centrifuged at 500 x g for 20 minutes. Mononuclear cells in the interface were collected into R10.