Reduced T cell–dependent antibody production against HBsAG and H. polygyrus in SFR KO mice. (A and B) WT and SFR KO mice were immunized i.p. with HBsAg vaccine (1 µg per mouse) and alum. Anti-HBsAg antibodies in serum were monitored over time. The protocol (A) and levels of anti-HBsAg IgM and IgG1 (B) are represented (WT, n = 8; KO, n = 7). Results are from one experiment. D, day. (C–G) One group of WT (n = 13; except for ELISA, n = 12, as serum from one mouse was not available) and SFR KO (n = 11) mice was infected orally with H. polygyrus. For another group (WT, n = 12; SFR KO, n = 12), infection was treated with Pyrantel at day 28 to clear the worms, and mice were reinfected at day 42. Mice were then analyzed 2 wk after primary or secondary infection. Results are pooled from two experiments. The protocol (C) and levels of HES-specific IgG1 (D and E) are depicted. Eggs in feces were enumerated (F), and worms in small intestine were visually enumerated (G). Data are pooled from two experiments. Each symbol represents a mouse. *, P < 0.05; **, P < 0.01; ***, P < 0.001; ****, P < 0.0001 (two-tailed Student’s t test). Data are presented as mean ± SEM. ns, not significant.