Figure 2. IgG-switched germinal centre B cells do not require ITT signalling.
Cohorts of sex- and age-matched male and female wild-type (wt) and ITT-mutant (YF) mice were immunized with NP–KLH. (a) Kinetics of germinal centre B-cell generation in the spleen. Relative frequency of B220-positive, CD38-negative cells among mIgG1-expressing cells during the course of the experiment. (b) NP-specific splenic B cells were identified with NP8-PE. The percentage of NP-binding mIgG1-positive B cells is shown. (c) Kinetics of mIgM-positive, NP-binding splenic B cells. (d,e) The numbers of antibody forming cells (AFCs) per 106 splenocytes was determined by ELISPOT assays for IgG1 (d) and IgM (e). Numbers of analysed animals are as follows: a,b,c and e shows mean values±s.e.m. of three independent experiments with three animals per genotype and time point (that is, n=9 per time point and genotype). d shows data of two independent experiments (that is, n=6 per time point and genotype). Statistical significance was determined by Mann–Whitney test. **P<0.01.