AID and Caspase 8 Shape the Germinal Center Response through Apoptosis

作者：Boulianne Bryant; Rojas Olga L; Haddad Dania; Zaheen Ahmad; Kapelnikov Anat; Thanh Nguyen; Li Conglei; Hakem Razq; Gommerman Jennifer L^*; Martin Alberto

来源：The Journal of Immunology, 2013, 191(12): 5840-5847.

DOI：10.4049/jimmunol.1301776

Germinal centers (GCs) are clusters of activated B cells that form in secondary lymphoid organs during a T-dependent immune response. B cells enter GCs and become rapidly proliferating centroblasts that express the enzyme activation-induced deaminase (AID) to undergo somatic hypermutation and class-switch recombination. Centroblasts then mature into centrocytes to undergo clonal selection. Within the GC, the highest affinity B cell clones are selected to mature into memory or plasma cells while lower affinity clones undergo apoptosis. We reported previously that murine Aicda(-/-) GC B cells have enhanced viability and accumulate in GCs. We now show that murine Aicda(-/-) GC B cells accumulate as centrocytes and inefficiently generate plasma cells. The reduced rate of plasma cell formation was not due to an absence of AID-induced DNA lesions. In addition, we show that the deletion of caspase 8 specifically in murine GC-B cells results in larger GCs and a delay in affinity maturation, demonstrating the importance of apoptosis in GC homeostasis and clonal selection.

• 出版日期2013-12-15