Fig. 4: MuSK-CAART reduces anti-MuSK IgG but not total IgG or B cell counts in a syngeneic MuSK EAMG model.
CD45.2+ C57BL/6J mice were immunized with MuSK Ig1-2 protein (30 μg in complete Freund’s adjuvant) on day 0 and boosted with MuSK Ig1-Fz protein (30 μg in incomplete Freund’s adjuvant) on day 26. Results of two independent experiments are shown (total numbers NTD-T, n = 12, 1D3-CART, n = 8, MuSK-CAART, n = 12). Equivalent numbers of transduced CD45.1+ T cells or a matching number of NTD CD45.1+ cells were injected on day 35. a,b, Host B cells (CD45.2+CD3-CD19+) were analyzed in spleen and lymph nodes at days 49–63 (2–4 weeks after treatment). Representative flow plot (a) and the frequency of CD45.2+CD19+ B cells in the spleen and lymph nodes (b) are shown. Kruskal–Wallis test with Dunnett’s test for multiple comparisons. c, Anti-MuSK antibody titer was measured in individual mouse blood samples drawn on the day of treatment, normalized to 4A3 mouse antihuman MuSK mAb standard (µg ml−1). Kruskal–Wallis with Dunnett’s test for multiple comparisons. d,e, Anti-MuSK antibody titer and total mouse IgG were measured in mouse blood samples drawn weekly after treatment. Graphs indicate fold change of anti-MuSK antibody titer (d) or total mouse IgG (e) relative to week 1 after treatment (NTD-T, n = 8; 1D3-CART, n = 7 (d) and n = 6 (e); MuSK-CAART, n = 8 to include all mice with longitudinal samples through week 4 after treatment; one 1D3-CART mouse was excluded in e due to low blood sample volume precluding analysis). Error bars indicate mean ± s.e.m. Multiple linear regression-coefficient test for difference between the slopes. f, Frequency of CD45.1+ T cells were analyzed in the spleen and lymph nodes on day 49–63. Statistical analysis was not performed since absolute number of CD45.1+ T cells varied among treatment groups to achieve the same transduced cell dose in set 1. NS, P > 0.05; *P < 0.05; **P < 0.01; ***P < 0.001.
