Extended Data Fig. 7: Alcohol treatments that modulate BCR cluster domain contrast also modulate downstream Ca²⁺ mobilization responses.

a, Representative calcium mobilization traces for CH27 cells pretreated with n-alcohols and stimulated with 2.5 µg/ml F(ab’)₂ fragments against the µ subunit of IgM BCR, as measured by the calcium-sensitive dye Flou-4 AM (left). Baseline drift was corrected by fitting a line to the Fluo-4 fluorescence trace prior to antigen addition and dividing the entire fluorescence trace by this baseline. Hexadecanol (hex) or octanol (oct) were added from stock solutions in DMSO, or an equivalent final concentration of DMSO was added as a carrier control. Points are mean and s.e.m. from two technical replicates per condition. (Right) Maximum fluorescence signal from calcium traces normalized to maximum values for the DMSO treated control. Cells were stimulated with varied F(ab’)₂ concentrations (3.6, 3, 2.5 and 10 µg/ml). Peak values of fluorescence fold increase traces for hexadecanol or octanol-treated cells were normalized by peak values for DMSO-treated cells recorded during the same experiment with equivalent stimulation conditions. Colored symbols show mean and SE of 4 independent measurements. b, Calcium mobilization was measured and quantified as in a, but cells were stimulated via the PC-specific BCRs expressed by the CH27 cell line by addition of 100 nm lipid vesicles containing POPC lipids at 300 µg/ml (right). Same as in a but cells were stimulated with either 300 µg/ml POPC vesicles or vesicles composed of 1:1 mixture of POPC and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine. Colored symbols show mean and SE of 4 independent measurements. In both a and b, P values from a single-tailed t-test estimate the significance of deviations of responses of treated cells compared to the (normalized) DMSO control, while a two-tailed t-test is used to compare responses in Hex and Oct treated cells.