Fig 1. Epimastigote forms of T. cruzi and purified cruzipain activate latent TGF-β.
(A) Live epimastigotes (5 × 106) were incubated with latent TGF-β (100 ng) (LTGF-β) for 1 h at 28°C and the activated TGF-β was measured by ELISA. Insert: experimental controls performed in all assays (A, B and C): LTGF-β was incubated for 1 hour at 37°C (negative control) or for 10 minutes at 80°C (positive control). Levels of active TGF-β were measured in pg/ml. Activation of TGF-β was tested using different dilutions of (B) parasite lysate (equivalent to 0.07 to 2.5 × 106 cells) and (C) purified cruzipain (1.5 to 200 μg ml-1). White bars represent recombinant latent TGF-β incubated alone for 1 h at 28°C. Data are the mean ± standard deviation (SD). (*P < 0.05, ** P < 0.01, *** P < 0.001). n = 3.