FIGURE 1

Rapid onset mucosal IgA in L-Sel^-/- mice. Depicted are (a) fecal IgA and serum (c) IgA and (d) IgG anti-CT-B titers following oral immunization of L-Sel^-/- mice with CT. L-Sel^-/- and L-Sel^+/+ mice were orally immunized on days 0, 7, and 14. Serum and mucosal secretions were collected and assessed for immune Abs by CT-B ELISA. Although L-Sel^-/- fecal IgA anti-CT-B Abs decreased at 42 days, (b) S-IgA in nasal washes from L-Sel^-/- mice remained elevated. Results up to 42 days after primary immunization are depicted as the mean of 10 mice s.e.m., and statistical differences between L-Sel^-/- and L-Sel^+/+ mice were determined: *P<0.001; **P=0.006; ***P=0.021. Ab, antibody; CT, cholera toxin; ELISA, enzyme-linked immunosorbent assay; Ig, immunoglobulin; L-Sel, L-selectin.