MDC-mediated acceleration of disease. (a) Acceleration of diabetes in MDC-TG NOD mice. Diabetogenic potential was compared after adoptive transfer of splenocytes from (b) 8-week-old prediabetic (n = 3) or (c) 16- to 18-week-old diabetic (n = 3) MDC-TG and non-TG littermates into 8- to 10-week-old NOD-scid female recipients. Open circles, non-TG NOD littermates; filled circles, MDC-TG NOD mice. (d) MDC-mediated Th1 immune response. Splenocytes from 11-week-old MDC-TG and non-TG NOD females (three mice/group) were stimulated with the islet antigen, GAD65, presented by irradiated spleen cells as APCs. Culture supernatants were analyzed for cytokine secretion by ELISA. T cell proliferation was measured in response to GAD65 presented by APCs (e) or upon stimulation of costimulatory factors such as CD3/CD28 (f). Bars represent mean values ± SEM from two separate experiments. White bars and open circles, non-TG littermates. Black bars and filled circles, MDC-TG NOD females.