Overall rate of emigration (ORE) after intrathymic inoculation.
Control and 14 days-infected animals were injected intrathymically with FITC or FITC plus TNF-α. Twenty-four hours after, thymuses, spleens and subcutaneous lymph nodes were screened for FITC+ CD4/CD8-defined cell subsets and these data were adjusted in relation to the cellularity of each peripheral lymphoid organ and the percentage of thymus labelling, using the following formula: Overall rate of emigration (ORE) = (Absolute numbers of FITC+ cells×cellularity in the peripheral lymphoid organ)/(% of FITC+ cells in thymus). We verified an enlarged ORE values in infected animals, independently of whether they were inoculated or not with TNF-α. Data indicate that TNF-α promotes the output of immature DP+ cells to both spleen and subcutaneous lymph nodes. Absolute numbers of FITC+ cells, CD4+, CD8+ and DN cells was expressed on 1.104 cells, while DP+ cells was expressed on 1.103 cells. Cellularity of each peripheral lymphoid organ was expressed in 1.106 cells. Values are mean ± SEM of 5–6 mice/group (one representative experiment of two independent series). Difference between Control versus T. cruzi group = (*)p<0.05; (**)p<0.02. Differences between TNF-α treated versus not treated group = (Δ)p<0.05; (ΔΔ)p<0.02.