title: Precursor B cells of mouse bone marrow express two different complexes with the surrogate light chain on the surface.
abstract: Two monoclonal antibodies raised against the complex of mu heavy (H) chain and Vpre-B/lambda 5 surrogate light (L) chains recognize surrogate L chain in different conformations on normal pre-B cells. One, LM34 recognizes free lambda 5 protein and free lambda 5/Vpre-B surrogate L chains and binds to surrogate L chains on the surface of early, pro-B and pre-B-I cells where the surrogate L chain is associated with a gp130/gp35-65 complex of proteins. It also recognizes the surrogate L chain associated with the mu H chain on pre-B-II cells. The other monoclonal antibody, SL156, does not recognize free surrogate L chain or its components, nor its complex with gp130/gp35-65 on pro-B and pre-B-I cells. However, it does bind to a conformational epitope on the surrogate light chain/mu H chain complex on a subpopulation of pre-B-II cells and on mu H chain-positive pre-B cell lines. On mouse precursor B cells prepared ex vivo on ice, expression of the surrogate L chain is very low and almost undetectable. Incubation of the precursor cells for 1 h at 37 degrees C up-regulates the surface expression of surrogate L chain associated with gp130/gp35-65 (early complex) as well as the mu H chain/surrogate L chain complex. These results reconcile some of the apparently discrepant results on surface expression of the surrogate L chain obtained with human and mouse bone marrow pre-B cells, and show that a surrogate L chain/mu H chain-containing pre-B cell receptor can be expressed also on the surface of mouse pre-B-II cells.
authors.affiliation: Basel Institute for Immunology, Switzerland.
authors.forename: T H
authors.initials: TH
authors.lastname: Winkler
authors.forename: A
authors.initials: A
authors.lastname: Rolink
authors.forename: F
authors.initials: F
authors.lastname: Melchers
authors.forename: H
authors.initials: H
authors.lastname: Karasuyama
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D001402:B-Lymphocytes / Q000737:chemistry*; D001854:Bone Marrow Cells; D002460:Cell Line; D005260:Female; D006412:Hematopoietic Stem Cells / Q000737:chemistry*; D007147:Immunoglobulin Light Chains / Q000032:analysis*; D007075:Immunoglobulin M / Q000032:analysis; D007148:Immunoglobulin mu-Chains / Q000032:analysis; D017493:Leukocyte Common Antigens / Q000032:analysis; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D051381:Rats; D015375:Receptors, Interleukin-2 / Q000032:analysis
chemical_list: D000911:Antibodies, Monoclonal; D007147:Immunoglobulin Light Chains; D007075:Immunoglobulin M; D007148:Immunoglobulin mu-Chains; D015375:Receptors, Interleukin-2; D017493:Leukocyte Common Antigens