2B). Thus, early depletion of DCs before MOG immunization only mildly reduced the disease severity but did not influence the incidence of EAE. To examine the effect of DC depletion on FoxP3+ Treg cells, the Treg-cell numbers were assessed. DCs were depleted in vivo 1 day before MOG immunization and the frequency of absolute number

of FoxP3+ CD3+ Treg cells per spleen was measured 10 days after MOG immunization by flow cytometry. The mean number of Treg cells per spleen did not differ between DC-depleted and control CD11c-DTR mice (Fig. 3). Thus, in contrast to constitutive DC ablation, short-time depletion of DCs does not appear to affect learn more the Treg-cell responses in this system. When the experiments described above were performed, low mortality of CD11c-DTR

mice (one to two mice/experiment) was observed within the first week after DTx injection. In our hands, mortality increased over time when we ran new experiments (data not CP690550 included), as described by others [6]. Mortality was observed to the same extent in mice that had not received MOG injection, and the mortality was thus not caused by the MOG immunization (data not included), but probably due to aberrant DTR expression in nonimmune cells. To assure that immune cells were not depleted by the DTx injection, the frequency of B cells, CD11b+ cells, T cells and Ly6Chi CD11b+ monocytes were analyzed 24 h after DTx injection in the spleen from CD11c-DTR mice (Supporting Information Figure 1). The frequency of these cells was not affected by the DTx injection and EGFP expression was undetected in these cell types (data not included). Therefore, the increased mortality in CD11c-DTR mice was unlikely due to aberrant expression of DTR in immune cells other than mDCs. To reduce the mortality in CD11c-DTR mice following DTx injection [6] and obtain a better experimental design, bone marrow chimeras were generated. Bone marrow from CD11c-DTR donors was injected into lethally irradiated C57BL/6 hosts 6 weeks before EAE induction. No mortality was observed in the bone marrow chimeras following DTx injection (data not included). The efficiency of the DC depletion was again assessed

after DTx injection. Dermal DCs and mDCs from skin-draining LNs and spleen were depleted after DTx injection (Fig. 1D–F Methane monooxygenase and Supporting Information Table 1). Similar to CD11c-DTR mice, around 50% of inflDC were depleted (Fig. 1E–F) but not pDCs (data not included). Depletion of mDCs and inflDCs in the CNS was analyzed at peak of EAE (day 13 after MOG immunization) when detectable amounts of DCs are present in the CNS [15]. mDCs and inflDCs were abundant in both DC-depleted and controls and were as expected not depleted at this late time point (Fig. 1G). The inflDCs of the CNS expressed very high levels of CD11b (data not included). Thus, mDCs but not pDCs were depleted by the DTx injection in bone marrow chimeras to the same extent as in CD11c-DTR mice.