نتایج جستجو برای: germinal cells
تعداد نتایج: 1386674 فیلتر نتایج به سال:
BACKGROUND AND OBJECTIVES In the present paper we report that SAP, an intracytoplasmic molecule that is involved in cell signaling, is an immunohistologic marker for germinal center T cells in paraffin-embedded tissue. We document its expression, and also that of PD-1 (another recently described marker of germinal center T cells to which a new antibody has been raised), in normal and neoplastic...
The human germinal centre-associated lymphoma gene is specifically expressed in germinal centre B-lymphocytes and germinal centre-derived B-cell lymphomas, but its function is largely unknown. Here we demonstrate that human germinal centre-associated lymphoma directly binds to Syk in B cells, increases its kinase activity on B-cell receptor stimulation and leads to enhanced activation of Syk do...
The secretion of specific antibodies and the development of somatically mutated memory B cells in germinal centers are consequences of T cell-dependent challenge with the hapten (4-hydroxy-3-nitrophenyl)acetyl (NP). Using six-parameter flow cytometry and single cell molecular analysis we can directly monitor the extent of somatic hypermutation in individual responsive (isotype switched) antigen...
Immunization with T cell–dependent antigens generates long-lived memory B cells and antibody-forming cells (AFCs). Both populations originate in germinal centers and, predominantly, produce antibodies with high affinity for antigen. The means by which germinal center B cells are recruited into these populations remains unclear. We have examined affinity maturation of antigen-specific B cells in...
Modern technology has created a vast pool of chemical pollutants that invade man's environment daily. The mutagenic, teratogenic, and carcinogenic potentials of the majority of these chemicals have not yet been evaluated. It is vital to screen as many of these substances as is feasible for their genetic risks, with the ultimate goal of eliminating the potentially hazardous compounds from the en...
Autoradiographic studies of lymphoid tissue with tritiated thymidine ([3H]TdR) have repeatedly demonstrated that thymus lymphocytes and germinal-center cells of lymph nodes and spleen are characterized by a weak labeling, whereas the majority of lymph node lymphocytes which occur outside of the germinal centers are intensely labeled (1-7) . An earlier study on mice by Osogoe and Ueki (8), on th...
Mice rendered deficient in CD28 signaling by the soluble competitor, cytotoxic T lymphocyte-associated molecule 4-immunoglobulin G1 fusion protein (CTLA4-Ig), fail to upregulate OX40 expression in vivo or form germinal centers after immunization. This is associated with impaired interleukin 4 production and a lack of CXC chemokine receptor (CXCR)5 on CD4 T cells, a chemokine receptor linked wit...
In the genetically restricted response that follows immunization with (4-hydroxy-3-nitrophenyl)acetyl coupled to protein carriers, two distinct populations of B cells are observed in the spleens of C57BL/6 mice. By 48 h postimmunization, foci of antigen-binding B cells appear along the periphery of the periarteriolar lymphoid sheaths. These foci expand to contain large numbers of antibody-formi...
Active germinal centers are recognized as areas of rapidly proliferating blast cells in the white pulp of the spleen and in the cortex of lymph nodes. The origin and life history of these cells, their relationship to the surrounding mantle zone of small lymphocytes and, in particular, the functional significance of these two groups of cells is still unknown. Flemming (1) has proposed that germi...
background: routine oocytes cryopreservation remained an elusive technique in the wide ranges of available assisted reproductive technologies. the microtubules of oocytes are vulnerable to cryoprotectants and thermal change during cryopreservation. objective: the effects of a vitrification protocol were investigated on the spindle and chromosome configurations of mice oocytes cryopreserved at t...
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