B cell maturation activation and differentiation pdf
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- Activation and Regulation of B Cell Responses by Invariant Natural Killer T Cells
- B cell activation and the germinal centre response
- 12.3F: B-Lymphocytes (B-Cells)
Describe the overall function of B-lymphocytes and their activation by T-dependent antigens in terms of the following:. B-lymphocytes B-cells are responsible for the production of antibody molecules during adaptive immunity. Antibodies are critical in removing extracellular microorganisms and toxins.
Activation and Regulation of B Cell Responses by Invariant Natural Killer T Cells
B cells , also known as B lymphocytes , are a type of white blood cell of the lymphocyte subtype. B cells, unlike the other two classes of lymphocytes, T cells and natural killer cells , express B cell receptors BCRs on their cell membrane. B cells develop from hematopoietic stem cells HSCs that originate from bone marrow. B cells undergo two types of selection while developing in the bone marrow to ensure proper development, both involving B cell receptors BCR on the surface of the cell. To complete development, immature B cells migrate from the bone marrow into the spleen as transitional B cells , passing through two transitional stages: T1 and T2. B cell activation occurs in the secondary lymphoid organs SLOs , such as the spleen and lymph nodes.
B cell activation and the germinal centre response
Eran Diamant, Zohar Keren, Doron Melamed; CD19 regulates positive selection and maturation in B lymphopoiesis: lack of CD19 imposes developmental arrest of immature B cells and consequential stimulation of receptor editing. Blood ; 8 : — Ligand-independent signals that are produced by the B-cell antigen receptor BCR confer an important positive selection checkpoint for immature B cells. Generation of inappropriate signals imposes developmental arrest of immature B cells, though the fate of these cells has not been investigated. Studies have shown that the lack of CD19 results in inappropriate signaling. In immunoglobulin transgenic mice, this inappropriate signaling impairs positive selection and stimulates receptor editing. Here, we studied the extent and significance of receptor editing in CDregulated positive selection of normal, nontransgenic B lymphopoiesis, using our bone marrow culture system.
B-CELL GENERATION, ACTIVATION, AND DIFFERENTIATION. I. B-Cell Maturation. A. Bone-Marrow Environment. B. Ig-Gene Rearrangements. C. Pre-B-Cell.
12.3F: B-Lymphocytes (B-Cells)
Tucker W. LeBien, Thomas F. Tedder; B lymphocytes: how they develop and function. Blood ; 5 : — The discovery that lymphocyte subpopulations participate in distinct components of the immune response focused attention onto the origins and function of lymphocytes more than 40 years ago.
Contributors and Attributions
CD1d-restricted invariant natural killer T iNKT cells play central roles in the activation and regulation of innate and adaptive immunity. Cytokine-mediated and CD1d-dependent interactions between iNKT cells and myeloid and lymphoid cells enable iNKT cells to contribute to the activation of multiple cell types, with important impacts on host immunity to infection and tumors and on the prevention of autoimmunity. Here, we review the mechanisms by which iNKT cells contribute to B cell maturation, antibody and cytokine production, and antigen presentation. Cognate interactions with B cells contribute to the rapid production of antibodies directed against conserved non-protein antigens resulting in rapid but short-lived innate humoral immunity. Depletions and functional impairments of iNKT cells are found in patients with infectious, autoimmune and malignant diseases associated with altered B cell function and in murine models of these conditions. The adjuvant and regulatory activities that iNKT cells have for B cells makes them attractive therapeutic targets for these diseases.
B cells are activated when their B cell receptor BCR binds to either soluble or membrane bound antigen. This activates the BCR to form microclusters and trigger downstream signalling cascades. The microcluster eventually undergoes a contraction phase and forms an immunological synapse, this allows for a stable interaction between B and T cells to provide bidirectional activation signals. Once activated B cells may undergo class switch recombination. They do this by excision of the unwanted isotypes Figure 1. Cytokines produced by T cells and other cells are important in determining what isotype the B cells express. B cells have two main types of immune responses.