Figure 3. Depletion of CD301b+ DCs leads to enhanced antibody responses to the antigen immunized with weak or no adjuvant.
(a) Immunization and sample collection timeline. (b) Mgl2-DTR mice were treated with 0.5 µg DT or its inactive mutant CRM197 (CRM) on days -1 and +2 and immunized on day 0 with 50 µg papain plus indicated amount of OVA in the footpad. All mice received i.p. injection of 10 µg OVA without adjuvant on day 14 and sera were harvested on day 21 for OVA-specific antibody ELISA. (c) WT and Mgl2-DTR mice were treated with 0.5 µg DT on days −1 and +2 and immunized in the footpad with 5 µg OVA without any adjuvant on day 0 (top). Alternatively, lethally-irradiated WT mice were reconstituted with Mgl2-DTR (DTR only), WT (WT only) or 1:1-mixture of WT and Mgl2-DTR (WT+DTR) BM cells, then immunized with 5 µg OVA without adjuvant (bottom). All mice received i.p. injection of 10 µg OVA without adjuvant on day 14 and day 21, and sera were harvested on day 21 and day 28 for OVA-specific IgG1 ELISA. Bars indicate mean ± S.E.M. calculated from 4–11 individual mice. n.s., not significant, *p<0.05, **p<0.01, ***p<0.001, ****p<0.0001 by two-tailed Student’s t-test. All statistics indicate comparison to the undepleted (CRM-treated, WT or WT only BM chimera) control shown in each panel.