CD300a-Ig binds to dead cells. (A) Human starved PBMCs from a healthy donor were labeled with Alexa Fluor 488 (AF488)–CD300a-Ig (empty histograms) or control AF488-LAIR-1-Ig (filled histograms). Three groups of cells were electronically gated based in their forward scatter (FSC) and side scatter (SSC). Data shown are representative of at least 5 experiments. (B) Starved PBLs from a healthy donor were stained with allophycocyanin (APC) annexin-V, 7-AAD, AF488-CD300a-Ig, or control AF488-LAIR-1-Ig. The binding of AF488-CD300a-Ig (empty histograms) and AF488-LAIR-1-Ig (filled histograms) was determined on live (annexin-V⁻7-AAD⁻), early apoptotic (annexin-V⁺7-AAD⁻) and late apoptotic/necrotic (annexin-V⁺7-AAD⁺) cells. Data shown are representative of at least 5 independent experiments. (C) Dexamethasone-treated DT40 chicken B cells (top panel) and serum starved Sf-9 insect cells (bottom panel) were either unlabeled or labeled with 7-AAD, AF488-CD300a-Ig or control AF488-LAIR-1-Ig and analyzed by flow cytometry. Data shown are representative of 2 independent experiments.