Abstract
The germinal center (GC) is the site where B cells undergo clonal expansion, affinity-based selection, and differentiation into memory B cells or plasma cells. It has been difficult to elucidate regulatory mechanisms for the dynamic GC B cell maturation and differentiation, partly because experimental manipulation of GC B cells in vivo has been limited and no in vitro system has been available that resembles B cell reaction in GC. Here we describe the protocol for a culture system named "induced GC B (iGB) culture system" which can induce massive expansion of B cells that exhibit GC B cell-like phenotype, and thus it mimics the GC reaction. This protocol can be useful to elucidate the molecular mechanisms of GC B cell differentiation.