Binding and Endocytosis of Bovine Hololactoferrin by the Parasite Entamoeba histolytica

Figure 4

Entamoeba histolytica binding to B-holo-Lf is dependent of pH and it was increased in presence of Ca²⁺ and Fe³⁺. (a) Amoebae were synchronized and preincubated (10⁶ cells) with buffers (pH 2–8) at 6°C for 30 min. Next, fresh medium containing FITC-B-holo-Lf was added and incubated for 30 min. The samples were washed and fixed with PFA, and fluorescence quantification was analyzed by flow cytometry. (b) Amoebae (10⁶ cells) in low iron were preincubated at 6°C for 30 min with one of the following cations: 0–25 mM of CaCl₂, FeCl₃, MgCl₂, or FeSO₄. Next, amoebae were washed with PBS, and fresh medium containing FITC-B-holo-Lf was added and incubated for 30 min. The samples were washed and fixed with PFA, and fluorescence quantification was analyzed by flow cytometry. White symbols indicate the nonvirulent amoebae and black symbols indicate the virulent amoebae. Values are means of three independent experiments performed in triplicate ± SD.

(a)

(b)