Expression data from murine wildtype and Sh3gl1-/- B cells

We show that antigen internalization depends both on constitutive, clathrin-mediated endocytosis and on antigen-induced, clathrin-independent endocytosis mediated by endophilin A2. Although endophilin A2-mediated endocytosis is dispensable for antigen presentation, it is selectively required for metabolic support of B cell proliferation, in part through regulation of iron uptake. Consequently, endophilin A2 deficient mice show defects in GC B cell responses and production of high-affinity IgG. The requirement for endophilin A2 highlights a unique importance of clathrin-independent intracellular trafficking in GC B cell clonal expansion and antibody responses Overall design: Wildtype or Sh3gl1 knockout transitional and follicular B cells were sorted by flow cytometry and used for RNA isolation. Follicular B cells from both genotypes were also treated with CD40L for 14 hours and RNA isolated for comparison. Three biological replicates were included from littermates of appropriate genotype.