Figure 6

FCM detection of PD-1 and CTLA-4 on the surface of CD4⁺CD25⁺Foxp3⁺Treg cells in peripheral blood, mediastinal draining lymph nodes, and spleen of mice. To evaluate whether Treg cells in this study could play their role by contact inhibition, the surface expression of two major negative co-stimulatory molecules were detected by FCM. Freshly isolated cells from blood, mediastinal draining lymph nodes and spleen were stained with fluorescently antibodies for CD4, CD25, Foxp3 and PD-1 or CTLA-4. The results showed a significantly higher levels of PD-1 and CTLA-4 on the surface of Treg cells in MAPs treated mice than in control mice and OVA treated mice (gating on CD4⁺CD25⁺ cells).