Figure 4.

Germinal center B cell responses and affinity maturation to NP-CGG are impaired in Cγ1^Cre/wtPtpn6^fl/fl mice

(A) Germinal center B cell responses in popliteal lymph nodes (PLN) 8 days post NP-CGG immunization of Cγ1^Cre/wtPtpn6^fl/wt ROSA^mTmG and Cγ1^Cre/wtPtpn6^fl/fl ROSA^mTmG mice. Sequential gating strategy for the identification of PCs (lymphocytes/singlets/live/tomato⁻GFP⁺B220⁻CD138⁺) and GC B cells (lymphocytes/singlets/live/tomato⁻GFP⁺CD138^-B220⁺CD38⁻Fas⁺).

(B) Summary of PC and GC B cell numbers (% of live cells and total numbers per LN); three independent experiments.

(C) Active caspase-3 on GC B cells from PLNs 8 days post NP-CGG immunization (% of GC B cells; results are representative of one experiment).

(D) SYK phosphorylation in GC B cells (MFI on GC B cells).

(E) Relative percentage of GC area containing cMYC-expressing cells. Each symbol represents a different GC. Data combined from two independent experiments.

(F) Splenic NP-specific GC B cells at different time points after immunization (total cell numbers per spleen; results are from one to two independent experiments).

(G) Serum antibody titers for NP-specific IgG1 (left panel) and relative affinity of NP-specific IgG1 (right panel).

Results are from two to three independent experiments; horizontal lines indicate the mean. n.s. not significant, ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001 (B–E two-tailed t test and F–G two-way ANOVA).