The Role of Sialyl Glycan Recognition in Host Tissue Tropism of the Avian Parasite Eimeria tenella
Figure 3
EtMIC3 binds cell surface sialylated carbohydrates.
(a) Western blot analysis of a sporozoite lysate (lys) and the cell-bound (CB) fraction of the lysate after incubation on MDBK cells. Proteins were detected using specific antisera to EtMIC1, EtMIC2, EtMIC3 and EtMIC4. All four proteins were detected in the sporozoite lysate, but only EtMIC3 was detected in the cell bound protein fraction of this assay this. It is useful to note that cell binding activity has been reported for the EtMIC4/5 complex [11], but the assay protocol used in this work is less sensitive and unable to detect it. The faint band below EtMIC3 is likely to be a break down product. (b) Dose-dependent bindg of a sporozoite lysate containing EtMIC3 to fixed MDBK cell monolayers determined by cell based ELISA. Sporozoite lysate was diluted in PBS at a range of concentrations from 2 mg/ml - 0.001 mg/ml. The lysate was incubated with gluteraldehyde fixed MDBK cell monolayers. Cells were washed to remove unbound protein and binding of EtMIC3 was determined by ELISA. Error bars indicate standard deviations. (c) Western blot analysis of EtMIC3 from a sporozoite lysate (20×106/ml) within cell bound (CB) or unbound (UB) fractions of a sporozoite lysate in the presence of neuraminidase (c), (d) fetuin or asialofetuin.