Memory B cells and CD27

K. Agematsu

Department of Pediatrics, Shinshu University School of Medicine, Matsumoto, Japan

Offprint requests to: Dr. Kazunaga Agematsu, Department of Pediatrics, Shinshu University School of Medicine, Asahi 3-1-1, Matsumoto 390-8621, Japan. Fax: 0081-263-37-3089. e-mail: agemats@gipac.shinshu-u.ac.jp

Summary. Following antigen activation in germinal centers, B cells develop into memory B cells or plasma cells. Triggering via B-cell immunoglobulin receptors by antigens, cytokines and direct cell-to-cell contact by B and T cells plays an important role in the B cell differentiation into memory or plasma cells. Adult human peripheral blood B cells are separated into three subtypes by the expression of IgD and CD27, which belong to the tumor necrosis factor receptor (TNFR) family: IgD+ CD27- naive B cells, IgD+ CD27+ and IgD- CD27+ B cells. CD27+ B cells are larger cells with abundant cytoplasm carrying somatic hypermutation, and have an ability to produce immunoglobulin, indicating that CD27 is a memory marker of B cells. The ligation of CD27 yields crucial signals that positively control the entry of B cells into the pathway to plasma cells. We review observations on subpopulations and differentiation of mature B-cells by T/B cell interaction via CD27/CD70 as compared with CD40/CD154 interaction, and discuss about memory B cells. Histol. Histopathol. 15, 573-576 (2000)

Key words: Memory B cells, CD27, CD70, Plasma cells