title: Differentiation of germinal center B cells and follicular helper T cells as viewed by tracking Bcl6 expression dynamics.
abstract: Development of germinal center (GC) B cells and follicular helper T (Tfh) cells requires the transcription factor B-cell lymphoma 6 (Bcl6). Expression of Bcl6 in B cells and helper T cells is regulated by complex signals including those generated through their antigen-specific interactions, which take place in various microenvironments depending on their activation/differentiation states. In the last several years, it has become possible to detect Bcl6 protein in individual B cells and T cells by intracellular staining with the newly developed antibodies or by using the reporter mice. Experiments using these reagents have started to clarify microanatomical location of early Bcl6 upregulation in B cells and T cells, and contributed to reveal the dispensability and indispensability of B cells in the early and late phase of Tfh differentiation. They also started to reveal the diversity, plasticity, and/or instability of Tfh cells. We summarize the recent findings made by tracking Bcl6 expression together with the updated knowledge about dynamics of antigen-engaged B cells and helper T cells and discuss them in relation to possible signaling requirements for the development of GC B cells and Tfh cells.
authors.affiliation: Research Unit for Immunodynamics, RIKEN Research Center for Allergy and Immunology, Yokohama, Kanagawa, Japan. tokada@rcai.riken.jp
authors.forename: Takaharu
authors.initials: T
authors.lastname: Okada
authors.forename: Saya
authors.initials: S
authors.lastname: Moriyama
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kitano
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology*; D002454:Cell Differentiation; D004268:DNA-Binding Proteins / Q000378:metabolism*; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D018858:Germinal Center / Q000166:cytology*; D051379:Mice; D015398:Signal Transduction; D006377:T-Lymphocytes, Helper-Inducer / Q000166:cytology*
chemical_list: D004268:DNA-Binding Proteins