STRL33 expression on PBMCs.

We used 4-color FACS analysis to identify the various subpopulations of PBMCs indicated. Fresh whole blood was stained with fluorochrome-conjugated mAb within an hour of venupuncture, and FACS analysis was performed after ammonium chloride–mediated selective red blood cell lysis. STRL33 expression on (A) bulk CD4⁺, CD8⁺ T cells (CD3⁺), and CD19⁺ B cells; (B) CD4⁺ naive (CD45RA⁺/CD62L⁺) or memory (CD45RA⁻) T cells; and (C) NK cell subsets (R1, R2, and R3).