Figure 1.

Schematic of the germinal center: germinal centers consist of two major anatomic regions. The major cell types in the light zone (LZ) and dark zone (DZ) are shown. B cell centrocytes undergo selection in the light zone and then migrate to the dark zone where the B cell centroblasts proliferate and undergo somatic mutation before cycling back to the light zone. After several cycles, B cells differentiate into memory cells or plasma cells and exit the germinal center. Defects in germinal center cells or functions that result in spontaneous germinal center formation and loss of tolerance to nucleic acid antigens are shown on the right.