Figure 7. Depletion of CD301b+ DCs leads to GC B cell expansion in response to immunization with OVA and papain.
(a,b) WT and Mgl2-DTR (DTR) mice were treated with DT on days −1 and +2 and immunized with 50 µg papain and 5 µg OVA in 20 µl PBS in the right footpad. The left non-draining (L) or right draining (R) popliteal LNs were harvested on indicated days post immunization (d.p.i) and analyzed for the development of GC B cells (GL7+ CD95+). Mice that were treated with DT but left unimmunzed were analyzed at 7 d.p.i. (eight days from the first DT treatment) and are indicated as ‘Naïve’. Flow-cytometry panels in b are representative of data from day seven. (c) WT and Mgl2-DTR mice were treated with DT on days −1 and +2 and immunized on day 0 with 5 µg OVA with 50 µg papain as in Figure 2. On day 14, dLNs were harvested and cells were stained for the cell-surface markers as well as for their binding to Alexa488-conjugated OVA protein (A488-OVA). (d–g) Intracellular binding to A488-OVA (d,f) and CD138 expression (e,g) by activated IgD- B cells. (h–j) CD38 and GL7 expression in total B cells. (k,l) Cell-surface IgD expression and intracellular A488-OVA binding in naïve/memory (CD38+GL7-) B cells (k) and GC (CD38-GL7+) B cells (l) gated as in e. In all graphs, each dot indicates an individual mouse and the data were pooled from two independent experiments. n.s., not significant, *p<0.05, **p<0.01, ***p<0.001, ****p<0.0001 by two-tailed Student’s t-test. Bars indicate means ± S.E.M.
Figure 7—figure supplement 1. Cellular kinetics in CD301b+ DC-depleted mice immunized with papain and OVA.
