![]() Once differentiated, they are now considered mature B cells, or naive B cells. T2 B cells differentiate into either follicular (FO) B cells or marginal zone (MZ) B cells depending on signals received through the BCR and other receptors. Within the spleen, T1 B cells transition to T2 B cells. Throughout their migration to the spleen and after spleen entry, they are considered T1 B cells. 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. ![]() This negative selection process leads to a state of central tolerance, in which the mature B cells do not bind self antigens present in the bone marrow. Negative selection occurs through the binding of self-antigen with the BCR if the BCR can bind strongly to self-antigen, then the B cell undergoes one of four fates: clonal deletion, receptor editing, anergy, or ignorance (B cell ignores signal and continues development). If these receptors do not bind to their ligand, B cells do not receive the proper signals and cease to develop. Positive selection occurs through antigen-independent signalling involving both the pre-BCR and the BCR. Early B cell development: from stem cell to immature B cellī 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. From here, their development into B cells occurs in several stages (shown in image to the right), each marked by various gene expression patterns and immunoglobulin H chain and L chain gene loci arrangements, the latter due to B cells undergoing V(D)J recombination as they develop. HSCs first differentiate into multipotent progenitor (MPP) cells, then common lymphoid progenitor (CLP) cells. Development ī cells develop from hematopoietic stem cells (HSCs) that originate from bone marrow. B cell receptors are extremely specific, with all BCRs on a B cell recognizing the same epitope. BCRs allow the B cell to bind to a foreign antigen, against which it will initiate an antibody response. In birds, B cells mature in the bursa of Fabricius, a lymphoid organ where they were first discovered by Chang and Glick, which is why the B stands for bursa and not bone marrow, as commonly believed.ī cells, unlike the other two classes of lymphocytes, T cells and natural killer cells, express B cell receptors (BCRs) on their cell membrane. In mammals, B cells mature in the bone marrow, which is at the core of most bones. In addition, B cells present antigens (they are also classified as professional antigen-presenting cells, APCs) and secrete cytokines. When a naïve or memory B cell is activated by an antigen, it proliferates and differentiates into an antibody-secreting effector cell, known as a plasmablast or plasma cell. B cells produce antibody molecules which may be either secreted or inserted into the plasma membrane where they serve as a part of B-cell receptors. ![]() They function in the humoral immunity component of the adaptive immune system. Basic B cell function: bind to an antigen, receive help from a cognate helper T cell, and differentiate into a plasma cell that secretes large amounts of antibodies 3D rendering of a B cellī cells, also known as B lymphocytes, are a type of white blood cell of the lymphocyte subtype.
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