Fig. 1

Abatacept decreased disease activity in mice depleted of CD4⁺ T cells by GK1.5. a Collagen-induced arthritis was induced in male DBA/1 mice. When 80 % of the mice showed signs of arthritis, treatment was started. One day before the start of treatment, CD4⁺ T cells were depleted by intraperitoneal administration of GK1.5, and the depletion was continued until the end of follow-up. Treatment was administered by intraperitoneal injection of either PBS (diamonds), GK1.5 (CD4 depletion) (squares), abatacept (circles) or a combination of GK1.5 and abatacept (triangles). The mice were scored three times per week for inflammation in the paws to monitor disease progression. b Clinical scores over time of the different treatment groups. c Changes in clinical scores starting from the day treatment was initiated in the different treatment groups. d Number of affected paws per treatment starting from the day treatment was initiated. e Number of affected paws with a clinical score of 5 or higher (considered to be severely affected paws) per treatment starting from the day treatment was initiated. f Clinical scores of paws that showed signs of arthritis at the start of treatment and extending over time, per treatment. g Clinical scores of paws that did not show signs of arthritis at the start of treatment, per treatment, over time. Values are mean ± SEM (n=11 per treatment group). Statistical analysis was performed using Student’s t test. *P < 0.05 abatacept + CD4 depletion vs CD4 depletion. CFA complete Freund’s adjuvant, IFA incomplete Freund’s adjuvant, PBS phosphate-buffered saline