Subepithelial B Cells of the Human Tonsil

1997 ◽  
pp. 58-69 ◽  
Author(s):  
M. Dono ◽  
S. Zupo ◽  
C.E. Grossi ◽  
N. Chiorazzi ◽  
M. Ferrarini
Keyword(s):  
B Cells ◽  
Human Tonsil

scholarly journals CD40-dependent and -independent activation of human tonsil B cells by CpG oligodeoxynucleotides

2003 ◽  
Vol 33 (6) ◽  
pp. 1576-1585 ◽  
Author(s):  
Florian Gantner ◽  
Patrice Hermann ◽  
Kosuke Nakashima ◽  
Satoko Matsukawa ◽  
Katsuya Sakai ◽  
...  
Keyword(s):  
B Cells ◽  
Human Tonsil ◽  
Cpg Oligodeoxynucleotides

scholarly journals Antigenic phenotype and functional characterization of human tonsil B cells

Blood ◽  
1988 ◽  
Vol 71 (4) ◽  
pp. 1048-1055
Author(s):  
N Gadol ◽  
MA Peacock ◽  
KA Ault
Keyword(s):  
B Cells ◽  
Germinal Center ◽  
Functional Characterization ◽  
Pokeweed Mitogen ◽  
Functional Responses ◽  
Mantle Zone ◽  
Human Tonsil ◽  
Color Flow ◽  
Two Populations ◽  
Germinal Center B Cells

Human tonsil cells were labeled with anti-leu-16, a monoclonal antibody (MoAb) that recognizes the CD20 antigen and that is specific for B cells. Two populations of B cells were identified by flow cytometry on the basis of antigen density. One labeled brightly with anti-Leu-16, and the other labeled at a level comparable to blood B cells. These two populations were characterized with a panel of MoAbs in two- and three- color flow cytometric studies and appeared to correspond to germinal- center and mantle-zone B cells. The pattern of staining of anti-Leu-16 on sections of frozen tonsil supported this characterization. Anti-Leu- 16 labeled germinal center cells more intensely than mantle zone cells and stained a few scattered B cells in the interfollicular zone. The ability of each Leu-16+ population to secrete IgG and IgM in response to mitogens was measured in a particle immunofluorescence assay. Dim Leu-16+ B cells (small, resting B cells and a subpopulation of preactivated cells) secreted IgG and IgM in response to pokeweed mitogen (PWM) but only IgG in response to B cell growth factor (BCGF). Bright Leu-16+ B cells (small to large activated cells and possibly memory cells) did not respond to PWM but secreted IgG in response to BCGF. The functional responses of dim Leu-16+ and bright Leu-16+ B cells were consistent with their identification as mantle-zone and germinal-center B cells. Phenotypic identification and functional studies of mantle-zone and germinal-center B cells may help clarify the differentiation pathway within the germinal center.

scholarly journals Gap-Junction Communication Pathways in Germinal Center Reactions

1998 ◽  
Vol 6 (1-2) ◽  
pp. 111-118 ◽  
Author(s):  
Tibor Krenacs ◽  
Martin Rosendaal
Keyword(s):  
B Cells ◽  
Gap Junctions ◽  
B Cell ◽  
Germinal Center ◽  
Lucifer Yellow ◽  
Cell Communication ◽  
Germinal Centers ◽  
Lymphoid Tissues ◽  
Human Tonsil ◽  
Cell Fractions

Intercellular channels called gap junctions enable multicellular organisms to exchange information rapidly between cells. Though gap junctions are held to be ubiquitous in solid tissues, we have only recently found them in the lymphoid organs. Functional direct cell-cell communication has now been confirmed by us and other groups in bone marrow, thymus, and in secondary lymphoid tissues. What functions do they serve in the lymphoreticular system where, so far, only cytokines/growth factors and adhesion molecules have been considered as regulators? Here we show evidence for and refer to published work about functional direct cellcell communication through gap junctions in germinal center reactions and make proposals for their role in the immune response.We found a large amount of the connexin43 (Cx43) gap junctions in the germinal centers of secondary lymphoid follicles. Ultrastructurally and immunohistologically, most of the junctions were detected on the processes of follicular dendritic cells (FDC) enveloping nondividing centrocytes in the light zone of germinal centers where B-cell selection is thought to take place. Further support for this finding came by revealing the Cx43 mRNAin situat the same location as the protein. On antigen challenge, gap junctions appeared on the FDC as they formed meshworks in germinal centers. In order to find out which germinal center cells communicate directly, we separated FDC-rich, low-density, B-cell fractions from human tonsil. In culture, we injected single FDC with the low-molecular-weight fluorescent dye, Lucifer Yellow (Mr 457 Da), which passed between adjacent FDC and sometimes from FDC to B cells.Based on these findings and their assigned functions in other tissues, gap junctions may contribute to germinal center reactions in the following ways: (1) they may regulate follicle pattern formation by controlling FDC growth, (2) they may be involved in FDC-B-cell signaling contributing to the final rescue of selected B cells from apoptosis, and (3) they may enable FDC to work as a functional syncytium providing a cellular internet for integrating germinal center events. Data supporting these interpretations are briefly discussed.

scholarly journals Antigen Receptor Engagement Turns off the V(D)J Recombination Machinery in Human Tonsil B Cells

1998 ◽  
Vol 188 (4) ◽  
pp. 765-772 ◽  
Author(s):  
Eric Meffre ◽  
Fotini Papavasiliou ◽  
Paul Cohen ◽  
Odette de Bouteiller ◽  
Diana Bell ◽  
...  
Keyword(s):  
B Cells ◽  
Somatic Mutation ◽  
Somatic Mutations ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Light Chains ◽  
Immunoglobulin Gene ◽  
Antigen Receptors ◽  
Human Tonsil ◽  
Recombination Activating Gene ◽  
Cognate Antigen

The germinal center (GC) is an anatomic compartment found in peripheral lymphoid organs, wherein B cells undergo clonal expansion, somatic mutation, switch recombination, and reactivate immunoglobulin gene V(D)J recombination. As a result of somatic mutation, some GC B cells develop higher affinity antibodies, whereas others suffer mutations that decrease affinity, and still others may become self-reactive. It has been proposed that secondary V(D)J rearrangements in GCs might rescue B cells whose receptors are damaged by somatic mutations. Here we present evidence that mature human tonsil B cells coexpress conventional light chains and recombination associated genes, and that they extinguish recombination activating gene and terminal deoxynucleotidyl transferase expression when their receptors are cross-linked. Thus, the response of the recombinase to receptor engagement in peripheral B cells is the opposite of the response in developing B cells to the same stimulus. These observations suggest that receptor revision is a mechanism for receptor diversification that is turned off when antigen receptors are cross-linked by the cognate antigen.

Separation of precursor T cells and Ig-secreting B cells from the large lymphocytic cells of human tonsil

1977 ◽  
Vol 33 (2) ◽  
pp. 291-296 ◽  
Author(s):  
Jean-Jacques Ballet ◽  
Monique Agrapart ◽  
Anne Durandy ◽  
Claude Griscelli ◽  
Fritz Daguillard
Keyword(s):  
T Cells ◽  
B Cells ◽  
Human Tonsil

scholarly journals Engaging CD19 or target of an antiproliferative antibody 1 on human B lymphocytes induces binding of B cells to the interfollicular stroma of human tonsils via integrin alpha 4/beta 1 and fibronectin.

1995 ◽  
Vol 182 (5) ◽  
pp. 1191-1199 ◽  
Author(s):  
S Behr ◽  
F Schriever
Keyword(s):  
B Cells ◽  
B Cell ◽  
B Lymphocytes ◽  
Tyrosine Kinases ◽  
Matrix Protein ◽  
Extracellular Matrix Protein ◽  
Lymphoid Tissues ◽  
Human Tonsil ◽  
Humoral Immune ◽  
Secondary Lymphoid Organs

Adhesion of B lymphocytes within the different compartments of secondary lymphoid organs is essential for the function of the humoral immune response. It is not currently known how the temporary immobilization of B cells in distinct areas of this complex microenvironment is regulated. The present study aimed at defining B cell antigens that initiate binding of B cells to human tonsil sections in situ. Engaging the B cell antigens CD19 and target of an antiproliferative antibody 1 (TAPA-1) with monoclonal antibodies induced adhesion of these B cells to the interfollicular stroma. This binding occurred through the integrin alpha 4 beta 1 on the B cell surface and via the extracellular matrix protein fibronectin expressed in the interfollicular compartment of the tonsil. Signaling through either antigen, CD19 or TAPA-1, depended on tyrosine kinases. Binding induced by engaging CD19 required an intact cytoskeleton, whereas TAPA-1-transmitted adhesion did not. We suggest that CD19 and TAPA-1 have a novel and unique function by regulating an alpha 4 beta 1/fibronectin-mediated binding of B cells to the interfollicular stroma of lymphoid tissues.

scholarly journals A novel human B cell subpopulation representing the initial germinal center population to express AID

Blood ◽  
2006 ◽  
Vol 109 (6) ◽  
pp. 2545-2552 ◽  
Author(s):  
Grant R. Kolar ◽  
Darshna Mehta ◽  
Rosana Pelayo ◽  
J. Donald Capra
Keyword(s):  
B Cells ◽  
B Cell ◽  
Germinal Center ◽  
Somatic Hypermutation ◽  
Cytidine Deaminase ◽  
Cell Subpopulation ◽  
Human Tonsil ◽  
Germinal Center Reaction ◽  
Cell Subpopulations ◽  
Human B Cell

Abstract We have identified a novel mature human B-cell subpopulation in the human tonsil that has characteristics of both naive B cells and germinal center B cells including the expression of activation-induced cytidine deaminase (AID), which is essential for the process of immunoglobulin somatic hypermutation and class-switch recombination. These cells are clearly somatically hypermutated, albeit modestly. Their phenotype (IgD+CD38−CD23−FSChiCD71+) is unique and suggests they may be intermediate between both naive and germinal center cells. Morphologically they are also distinct from other B-cell subpopulations. The evidence presented suggests these cells may be the founder cells of the germinal center reaction (a pro-GC cell) and may be the normal counterpart of the mantle cell lymphoma cell.

Epigenetic mechanisms regulate ΔNP73 promoter function in human tonsil B cells

2011 ◽  
Vol 48 (4) ◽  
pp. 408-414 ◽  
Author(s):  
Claudio Brigati ◽  
Barbara Banelli ◽  
Ida Casciano ◽  
Angela Di Vinci ◽  
Serena Matis ◽  
...  
Keyword(s):  
B Cells ◽  
Epigenetic Mechanisms ◽  
Human Tonsil ◽  
Promoter Function
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