Figure 4.

Protection from diabetes resulting from EtxB treatment is mediated by regulatory CD4⁺ T cells 4–6-week-old NOD mice (top panel; six per group) were given 8 intranasal treatments with 10 µg EtxB mixed with 10 µg insulin. Ten−12-week-old female NOD mice (lower panel; six per group) were given 10 µg EtxB alone on eight occasions by intranasal administration. Two weeks after the final treatment, 5 × 10⁶ CD4⁺ spleen cells from treated mice were mixed with 5×10⁶ spleen cells from diabetic female NOD mice and were transferred i.v. into 10–12-week-old female NOD recipients (▪). Control recipients received spleen cells from diabetic mice alone (▿). Diabetes was diagnosed in groups of recipients (10 per group) on the basis of urinary glucose testing on alternate days.