Lambda Chain (B cells) (AP)

IGLV1-51: V segment of the variable region of immunoglobulins light chain that participates to the antigen recognition. Immunoglobulins (Igs), also known as antibodies, are membrane- bound or secreted glycoproteins produced by B lymphocytes. In the recognition phase of humoral immunity, the membrane-bound Igs serve as receptors which, upon binding of a specific antigen (Ag), trigger the clonal expansion and differentiation of B lymphocytes into Ig-secreting plasma cells. Secreted Igs mediate the effector phase of humoral immunity, which results in the elimination of bound antigens (PubMed:20176268, PubMed:22158414). The antigen binding site is formed by the variable region of one heavy chain, together with that of its associated light chain. Thus, each Ig has two antigen binding sites with remarkable affinity for a particular antigen. The variable regions are assembled by a process called V(D)J recombination and can then be subjected to somatic hypermutation after exposure to antigen to allow affinity maturation for a particular Ag (PubMed:20176268, PubMed:17576170). {ECO:0000303|PubMed:17576170, ECO:0000303|PubMed:20176268, ECO:0000303|PubMed:22158414}. Immunoglobulins are composed of two identical heavy chains and two identical light chains, linked by disulfide bonds. {ECO:0000303|PubMed:20176268}