TABLE 1.

Intracellular cytokine staining in lymph node cells from L. major-infected wild-type and TLR4^0/0 mice^a

Mouse strain	% CD4+ cells	% CD4+ IFN-γ+ cells	MFIb	% CD4+ IL-4+ cells	MFIb	% CD4+ IL-10+ cells	MFIb
Wild-type	50.3 ± 2.0	6.1 ± 1.2	5.4 ± 0.2	1.3 ± 0.1	4.5 ± 0.2	2.3 ± 0.7	4.0 ± 0.2
TLR40/0	52.1 ± 2.8	7.7 ± 3.3	6.2 ± 1.5	1.9 ± 0.7	5.6 ± 1.0	2.8 ± 1.1	4.6 ± 0.2

^aGroups of wild-type and TLR4^0/0 mice were infected with 2 × 10⁶ L. major promastigotes in one hind footpad. At 4 weeks postinfection, 5 × 10⁶ popliteal lymph node cells were stimulated with 10⁶ L. major parasites. Six days later, a Ficoll gradient was performed and the cells were restimulated with PMA and ionomycin in the presence of brefeldin-A, as described in Materials and Methods. The frequencies of IFN-γ-, IL-4-, and IL-10-expressing CD4⁺ T cells were determined by flow cytometry, and the values represent averages ± standard deviations for four mice. The results of one of two similar experiments are presented.

^bMFI, mean fluorescence intensity.