Stimulation with pLAg induces upregulation of activation/regulatory markers in CD4 T cells from CL patients. PBMCs were isolated from peripheral blood of CL patients (n = 10) and healthy subjects (n = 4), incubated with promastigote L. panamensis antigen (pLAg) for 5 days and stained for CD4, CD25, CD127, and CD69. A. Contour plots of cells within the CD4+ lymphocyte gate from one representative CL patient showing the effects of pLAg on the expression of CD25, CD127, and CD69. B. Expression of CD25 and CD69, and percentage of CD25hiCD127- cells within the CD4+ gate for healthy subjects and CL patients. **p < 0.01.