MyD88-deficient MSCs secrete IL-6 in response to poly(I:C) and differentiate into adipocytes but lack osteogenic and chondrogenic capacities. (A) Wild-type (▪) and 2 independent strains of MyD88-deficient MSCs (□, ⊡) were plated in MSC medium. Two days later, MSCs were treated with 20 μg/mL of TLR ligands. Conditioned media were collected from the cultures after 24 hours and assayed by ELISA for the presence of IL-6. The results represent the means ± SE of triplicate wells. Wild-type and 2 different batches of MyD88-deficient MSCs were induced to differentiate into adipocytes (Bii,iv,vi), osteocytes (Cii,iv,vi), and chondrocytes (Dii,iv,vi). After 3 weeks, cell cultures were fixed and stained with Oil red O (Bi-vi), Alizarin red (Ci-vi), and Alcian blue (Di-vi). Original magnifications: × 10 (B-C); × 20 (D).