Figure 2.

Ulvan activates heterophils in vitro in a time- and dose-dependent manner. Heterophils (8 × 10⁶/ml) were incubated in vitro with different concentrations of ulvan, PAM as TLR2 agonist, LPS as TLR4 agonist, and glycogen as a control of polysaccharide specificity. Activation was evidenced by the quantification of degranulation as evidenced by β-D-glucuronidase ability to generate 4-methylum-belliferone (A); and the measurement of the oxidative burst as evidenced by fluorescein fluorescence (B). Data represents the mean ± SEM of five independent experiments in triplicate. *p < 0.05, **p < 0.01 for statistically different values for the same dose at different times. Different letters with the same color indicate statistically different values for the different doses at the same time (p < 0.05).