Analyzing physiological function of polypeptide GalNAcT-1-deficient mice in humoral immunity

A family of polypeptide GalNAc transferases (ppGalNAcTs) initiates protein O-glycosylation. The ppGalNAcT gene family is large; at least 15 ppGalNAcT isozymes have been cloned so far and each of them may have important and distinctive physiologic functions. ppGalNAcT-1, which is highly expressed in many tissues and cell types, is the first member of the ppGalNAcT family to be cloned. In order to understand the physiologic role of ppGalNAcT-1, we generated and characterized mice lacking this isozyme. We found that ppGalNAcT-1 plays key roles in germinal center (GC) B lymphocyte apoptosis in the modulation of humoral immune response. In this chapter, in vitro and in vivo systems to assess the B lymphocyte function of ppGalNAcT-1-deficient mice are discussed. In addition, detailed information on the immunohistochemistry of GC is also described.