Table I.

Antigen-specific stimulation of CD4⁺CD25⁺ T cells by infected BMDCs

	CD4+CD25hi T cells from: a
	Chronically infected mice				Naive mice
Number of cell divisions	BMDCs	Infected BMDCs	LPS-treated BMDCs	Anti-CD40 and LPS-treated BMDCs	BMDCs	Infected BMDCs
0	93.2	32.9	82.1	86.3	74.7	68.5
1	4.4	33.7	15.5	7.4	18.9	19.5
2	1.2	14.3	2.2	3.8	4.5	6.6
3	1.2	15.3	0.2	1.6	1.1	3.4
4	0.0	3.8	0.0	0.9	0.9	1.9

Data are representative of at least two independent experiments.

^aCD4⁺CD25^hi T cells were sorted from the draining LNs of B/6 mice infected in the ear dermis with 10³ L. major metacyclic promastigotes for 5 mo or from the same LNs of naive mice. 5 × 10⁴ CFSE-labeled CD4⁺CD25⁺ T cells and 5 × 10⁵ BMDCs were cultured for 3 d. BMDCs were either untreated or previously incubated overnight with L. major metacyclic promastigotes or stimulated with 50 ng/ml LPS (alone or with 1 μg/ml anti-CD40). Cells were analyzed by flow cytometry, and cell divisions were analyzed on the gated CD4⁺TCR-β⁺ cells with ModFit software.