Surrogate light chain production during B cell differentiation: differential intracellular versus cell surface expression.
Expression of the surrogate light (psi L) chain genes encoding the VpreB and lambda 5/14.1 proteins is restricted to B-lineage cells. Pro-B and pre-B cells produce psi L chains, but whether both employ these as cell surface receptor components remains enigmatic. Recombinant human VpreB protein was used to generate a large panel of monoclonal anti-VpreB Abs to examine this issue. Native psi L chain proteins within pro-B cells as well as those serving as receptor components on pre-B cells were precipitated by 16 of the 26 anti-VpreB Abs. Surrogate light chains were easily detected on pre-B cell lines, whereas these anti-VpreB Abs reacted with pro-B cell lines only after plasma membrane permeabilization. The subpopulation of normal bone marrow cells bearing pre-B receptors included large and small pre-B cells exclusively, although pro-B cells also contained intracellular VpreB. VpreB proteins were not detected on or within B cells in bone marrow or the circulation, but a subpopulation of B cells in germinal centers was found to express the VpreB proteins intracellularly. Surrogate L chains are thus intermittently produced during human B-lineage differentiation, while their role as receptor components appears limited to the pre-B cell stage.
Department of Medicine, University of Alabama, Birmingham 35924-3300, USA.
Y H
YH
Wang
J
J
Nomura
O M
OM
Faye-Petersen
M D
MD
Cooper
D000911:Antibodies, Monoclonal / Q000096:biosynthesis / Q000378:metabolism; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D001854:Bone Marrow Cells / Q000276:immunology / Q000378:metabolism; D002454:Cell Differentiation / Q000276:immunology; D006801:Humans; D007074:Immunoglobulin G / Q000378:metabolism; D007147:Immunoglobulin Light Chains / Q000096:biosynthesis* / Q000276:immunology; D054444:Immunoglobulin Light Chains, Surrogate; D007135:Immunoglobulin Variable Region / Q000096:biosynthesis / Q000276:immunology / Q000378:metabolism; D007424:Intracellular Fluid / Q000276:immunology / Q000378:metabolism*; D008221:Lymphoid Tissue / Q000276:immunology / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000096:biosynthesis* / Q000276:immunology / Q000378:metabolism; D011947:Receptors, Antigen, B-Cell / Q000096:biosynthesis*; D011971:Receptors, Immunologic / Q000032:analysis / Q000276:immunology; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000276:immunology; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal; D007074:Immunoglobulin G; D007147:Immunoglobulin Light Chains; D054444:Immunoglobulin Light Chains, Surrogate; D007135:Immunoglobulin Variable Region; D008562:Membrane Glycoproteins; D011947:Receptors, Antigen, B-Cell; D011971:Receptors, Immunologic; D011994:Recombinant Proteins