Manabu Sugai

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We have identified a novel gene referred to as activation-induced deaminase (AID) by subtraction of cDNAs derived from switch-induced and uninduced murine B lymphoma CH12F3-2 cells, more than 80% of which switch exclusively to IgA upon stimulation. The amino acid sequence encoded by AID cDNA is homologous to that of apolipoprotein B (apoB) mRNA-editing(More)
Mesenchymal stromal cells are crucial components of secondary lymphoid organs (SLOs). Organogenesis of SLOs involves specialized stromal cells, designated lymphoid tissue organizer (LTo) in the embryonic anlagen; in the adult, several distinct stromal lineages construct elaborate tissue architecture and regulate lymphocyte compartmentalization. The(More)
Front-rear asymmetry in motile cells is crucial for efficient directional movement. The uropod in migrating lymphocytes is a posterior protrusion in which several proteins, including CD44 and ezrin/radixin/moesin (ERM), are concentrated. In EL4.G8 T-lymphoma cells, Thr567 phosphorylation in the COOH-terminal domain of ezrin regulates the selective(More)
We have developed an efficient in vitro class switching system using a subclone (CH12F3) of the IgM+ CH12.LX lymphoma cell line. CH12F3 cells switched from surface IgM+ cells to surface IgA+ cells at a high frequency (50%) after 72 h stimulation with IL-4, transforming growth factor (TGF)-beta and CD40L. No other class isotype-producing cells were detected,(More)
For efficient adaptive immunity, the lymph nodes (LNs) are equipped with a strategically organized microarchitecture, which is largely supported by the reticular network (RN). The RN can be clearly visualized by fluorescence immunohistochemistry coupled with confocal imaging using a monoclonal antibody, ER-TR7, and can be subdivided into four structurally(More)
The sophisticated microarchitecture of the lymph node, which is largely supported by a reticular network of fibroblastic reticular cells (FRCs) and extracellular matrix, is essential for immune function. How FRCs form the elaborate network and remodel it in response to lymphocyte activation is not understood. In this work, we established(More)
Sialic acid (Sia) is a family of acidic nine-carbon sugars that occupies the nonreducing terminus of glycan chains. Diversity of Sia is achieved by variation in the linkage to the underlying sugar and modification of the Sia molecule. Here we identified Sia-dependent epitope specificity for GL7, a rat monoclonal antibody, to probe germinal centers upon T(More)
Serum concentrations of immunoglobulin E (IgE) in normal circumstances are kept much lower than those of other Ig isotypes to avoid allergic reactions. B cells lacking Id2 have increased E2A activity, which leads to specific enhancement of germline transcription of the immunoglobulin epsilon locus. As a consequence, Id2-deficient B cells undergo class(More)
Class switch recombination (CSR) at the antibody immunoglobulin locus is regulated by germline transcription (GLT)-coupled modifications in the accessibility of the switch region, where CSR takes place. Here we show that histone acetylation of switch regions is linked to CSR but that histone acetylation cannot alone promote CSR or GLT. Activation-induced(More)
Pax5 activity is enhanced in activated B cells and is essential for class switch recombination (CSR). We show that inhibitor of differentiation (Id)2 suppresses CSR by repressing the gene expression of activation-induced cytidine deaminase (AID), which has been shown to be indispensable for CSR. Furthermore, a putative regulatory region of AID contains E2A-(More)