Depletion of Regulatory T Cells Augments a Vaccine-Induced T Effector Cell Response against the Liver-Stage of Malaria but Fails to Increase Memory
Figure 2
Treg that repopulated depleted DEREG-mice are functional suppressors.
(A) A F1 DEREG C57BL/6 x BALB/c-mouse were depleted by three consecutive DT injections and 30 days after depletion the Treg that repopulated the animals were sorted by flow cytometry due to their eGFP-expression (“new”Treg). Similarly GFP+Treg were sorted from an untreated F1 DEREG mice. Purity of both Treg preparation was>95%. Naïve spleen cells were stimulated with anti-CD3 and incubated with different amounts of the initial GFP+Treg (natural Treg, nTreg) before depletion and the GFP+ “new” Treg that reappear after depletion. After 48 h the supernatants were harvested and IL-2 production was measured by ELISA. The proliferation of cells was measured by 3H–Thymidin incorporation. Data are expressed as mean +/− SD. The experiment was repeated twice with similar results. (B) A similar assay was performed using either the initial Treg purified from F1 DEREG C57BL/6×BALB/c mice or those “new” Treg that reappear in these mice after depletion. Initial Treg or “new” Treg were incubated with different amounts of spleen cells from OT-1 T cell receptor transgenic mice, which were subsequently stimulated with SIINFEKL-peptide. After 48 h IL-2 production and proliferation of cells was measured. Data are expressed as mean +/− SD. The experiment was repeated once with similar results. ***p<0.0001.