Heca452 antibody

The Heca452 antibody (BD Bioscience, San Jose, CA, USA) was used to screen for Heca452 expression in plasma cells by IHC. Detailed methodology is provided in Supplementary Methods.

Murine pericytes were modified by enzymatic exofucosylation as previously reported (Garcia-Bernal et al., 2020 (link)). Briefly, cells were resuspended at 2 × 10⁷ cells/ml in fucosyltransferase VII (FTVII) reaction buffer composed of Hanks Balanced Salt Solution (HBSS, Gibco) containing 30 μg/ml fucosyltransferase VII (FTVII, R&D Systems), 20 mM HEPES (Thermo Fisher Scientific), 0.1% human serum albumin (Grifols) and 1 mM guanosine 5′-diphospho-β-L-fucose sodium salt (GDP-fucose, Sigma Aldrich), and incubated for 60 min at 37°C and 5% CO₂. Unmodified controls pericytes were treated only with GDP-fucose (w/o FTVII) in the same conditions as above. Cell viability after exofucosylation was assessed by trypan blue exclusion (usually 95% live cells). Efficacy of exofucosylation was evaluated by analysis of HECA452 antibody (BD Biosciences) staining and calcium-dependent mouse E-selectin/human IgG chimera (R&D Systems) binding by flow cytometry.