Fig. 1.

Administration of embryonic stem cell-derived mesenchymal stromal cells (hESC-MSC) ameliorates established collagen-induced arthritis (CIA). a Progression of arthritis after prophylactic administration of hESC-MSC in one experiment representative of two performed. Incidence (left panel) and arthritis score (right panel) were comparable to the control group when hESC-MSC were administered on the day of type II collagen (CII) immunization. b Dose-response effect of the therapeutic administration of hESC-MSC on arthritis score. Statistical differences between control and single-dose groups are indicated. c Amelioration of CIA induced by administration of three doses (arrowheads) of hESC-MSC is sustained in mice with established disease. Data pooled from three independent experiments with four to ten mice per experimental group. d Representative hematoxylin-eosin staining of joints after treatment with hESC-MSC in mice with established disease. *P < 0.05; **P < 0.01; ***P < 0.001