Expression of α-1 giardin in WB and GS trophozoites Although earlier studies localized

α-1 giardin at the outer edges of the microribbons of the ventral disc in WB trophozoites [40, 45], we observed α-1 giardin at the plasma membrane in these cells (Figure 4A). These results are consistent with those observed using a purified pAb against an immunodominant region of α-1 giardin or the AU-1 tagged α-1 giardin transfected trophozoites [19]. An assessment of α-1 giardin XMU-MP-1 in vitro localization in the GS strain showed this protein to occur at the plasma membrane as well. Also, α-1 giardin was present in a circular area of vesicles called “”the bare area”" and also probably in the paraflagellar dense rods, which accompany only the intracellular C646 solubility dmso portions of the corresponding axonemes [46]. Although the differential pattern of localization of α-1 AZD4547 mouse giardin in both strains suggests

an additional function of this protein in the B assemblage, supplementary data is still needed in order to reveal if there is a differential function of α-1 giardin in the GS trophozoites. Figure 4 Immunolocalization of α-1 giardin Giardia trophozoites. (A) Reactivity of G3G10 mAb on WB and GS Giardia trophozoites was determined by indirect immunofluorescence in permeabilized (upper panels) and non-permeabilized (lower panels) trophozoites. The arrowheads show the paraflagellar Urocanase dense rods and the arrows indicate the bare area. Scale bar: 10 μm. (B) Reactivity of G3G10 in permeabilized trophozoites of WB clone C6, WB clone A6, Portland-1 and P-15 strains. Scale bar: 10 μm. It has been previously suggested that the localization of α-1 giardin at the plasma membrane, as well as its glycosaminoglycan-binding activity, might be involved in the process by which the parasite binds to the intestinal epithelial cells, an event strongly related to virulence [19]. In the

present study, confirmation of the surface expression of α-1 giardin in WB and GS trophozoites was carried out by performing IFA, using non-permeabilized cells (Figure 4A). Next, we considered the possibility that the presence of α-1 giardin at the plasma membrane may be involved in surface attachment, as was previously demonstrated for δ-giardin [22]. Thus, GS and WB trophozoites were preincubated with mAbs against α-1 giardin, and then attachment, morphology, the presence of cell clusters and viability were analyzed. A time-point examination of the attachment was performed, and compared with trophozoites incubated with anti-VSP antibodies or a non-related antibody (positive and negative controls, respectively). Unlike the anti-VSP mAb, the anti-α1 giardin mAb did not show cell cluster formation or changes in the morphology of the WB (Table 2) or GS trophozoites (not shown).