*2.4. FabF8:Stx2 Antibodies Prevent Detachment and Swelling Caused by Stx2 in HGEC*

Morphology of HGEC treated with Stx2 in the presence of FabF8:Stx2 antibodies was evaluated. This recombinant antibody fragment significantly prevented HGEC detachment and intracellular edema caused by 0.5 ng/mL Stx2 (Figure 4A). The prevention obtained on cell detachment with pre-incubation and co-incubation conditions was 62.0 ± 4.0 and 45.0 ± 3.0 (*p* < 0.05, *n* = 3), respectively. In addition, cell detachment protection was significantly greater with pre-incubation than co-incubation (Figure 4B). However, when the cell area was analyzed, practically a total protection from swelling was achieved with FabF8:Stx2 with both experimental conditions assayed, pre-incubation: 95.0 ± 6.0% and co-incubation: 90.0 ± 5.5%, *p* < 0.05, *n* = 3 (Figure 4C).

**Figure 4.** FabF8:Stx2 protects human glomerular endothelial cells (HGEC) from Stx2-induced morphological alterations (**A**) Cell morphology was evaluated and the number of HGEC (**B**) were analyzed by light microscopy (×200 and ×400). HGEC areas (**C**) were measured using Image J software. The black arrows indicate intracellular edema. Results are expressed as means ± SD of three experiments. One hundred percent represents the values of controls. Stx2 vs. Ctrl, \* *p* < 0.05. Pre/co-incubation vs. Stx2, # *p* < 0.05.
