Fig. 1: MuSK-CAAR expression on primary human T cells directs specific cytolysis of anti-MuSK B cells that target unique epitopes.
a, Native MuSK is a transmembrane tyrosine kinase whose ectodomain comprises three immunoglobulin-like (Ig1–Ig3) and frizzled-like (Fz) domains. MuSK-CAAR comprises the native MuSK ectodomain, followed by a glycine/serine-rich linker, CD8α transmembrane domain (TMD) and CD137-CD3ζ intracellular costimulatory and activation domains. b, Primary human T cells were transduced with MuSK-CAAR lentivirus or NTD-T, and MuSK-CAAR expression was detected using anti-MuSK 4A3 or 189-1 antibody. MuSK-CAAR+ transduction efficiency in six different donor T cell batches (NTD-T and MuSK-CAART). Error bars indicate mean ± s.d. Unpaired t-test (two-tailed). c–g, Cytolysis of wild-type (control) Nalm-6 cells (c) and Nalm-6 anti-MuSK target cells 13-3B5/anti-Ig1 (d), 189-1/anti-Ig2 (e), 24C10/anti-Ig3 (f) and 192-8/anti-Fz (g) was measured using a luciferase-based cytotoxicity assay at 5 h (dashed line) and 24 h (solid line) after coculture with NTD-T (black), MuSK-CAART (red) and CART-19 (blue). The effector to target (E:T) ratio is based on total T cell number. h, Human IFNγ was measured in NTD-T, MuSK-CAART or CART-19 coculture supernatants (10:1 E:T, 24 h, experiments run using different T cell batches are shown in separate plots). One-way analysis of variance (ANOVA) with the Holm–Sidak test for multiple comparisons. For c–h, error bars indicate mean ± s.d. of triplicate cocultures and are representative of 2–4 independent experiments. NS, P > 0.05; *P < 0.05; ***P < 0.001; ****P < 0.0001.
