Fig. 3: IgGs from Myo+SD+ patients alter engineered cardiac tissue function and composition.

a, Representative bright-field images of engineered cardiac tissues after 14 days of culture with patient-specific purified IgG showing overall tissue morphology for each subgroup (scale bar, 500 μm). b, Representative immunofluorescence images of engineered cardiac tissue stained to show cardiomyocytes (α-actinin, red) and fibroblasts (vimentin, yellow) after 14 day culture with patient-specific IgG (scale bar, 50 μm). c, Quantification of the percentage of Ki-67-positive human cardiac fibroblasts after treatment with patient IgG; n = 3 healthy controls, n = 3 Myo− patients, n = 4 Myo+SD− patients and n = 4 Myo+SD+ patients (n = 8–12 independent replicate wells per patient sample; exact replicate values are included in Supplementary Table 1). d, Representative traces of calcium flux in engineered cardiac tissues after treatment with patient IgG. Values for each curve were normalized to the maximum value. e,f, Quantification of the percent change of the parameters tau (e) and FWHM (f) extracted from engineered cardiac tissue calcium transients after treatment with patient IgG compared to baseline. n = 3 healthy controls, n = 3 Myo− patients, n = 4 Myo+SD− patients and n = 4 Myo+SD+ patients (n = 4–6 independent replicate tissues per patient sample; exact replicate values are included in Supplementary Table 1). Data are represented as mean ± s.e.m. Symbol shapes represent different patients within each group. Statistical significance was determined by ordinary one-way ANOVA with Tukey’s test for multiple comparisons. CF, cardiac fibroblast; Ctrl, control; MFI, mean fluorescence intensity.