title: TAP-independent, beta 2-microglobulin-dependent surface expression of functional mouse CD1.1.
abstract: CD1 molecules consist of beta 2-microglobulin (beta 2m) noncovalently complexed to a non-major histocompatibility complex (MHC)-encoded monomorphic integral membrane protein homologous to MHC class I alpha chains. Little is known about the requirements for cell surface expression and T cell recognition of CD1. We inserted the mouse CD1.1 gene into vaccinia virus to create a recombinant virus expressing CD1.1 under the control of a viral promoter. Using this recombinant virus to infect normal or mutant cell lines, we found that the expression of molecules reactive with the CD1.1-specific monoclonal antibody 3C11 requires the expression of beta 2m but was not affected by the absence of the MHC-encoded peptide transporter (TAP). Consistent with these results, IL-2 production by the mCD1.1-specific T cell hybridoma DN32.D3 was induced by thymocytes from normal mice or mice with a homozygous deletion of the TAP1 gene, but not by thymocytes from mice with a homozygous deletion of the beta 2m gene. These results indicate that expression of functional mCD1.1 occurs in a beta 2m-dependent, TAP-independent manner.
mesh_terms: D000071181:ATP Binding Cassette Transporter, Subfamily B, Member 2; D000071450:ATP Binding Cassette Transporter, Subfamily B, Member 3; D018528:ATP-Binding Cassette Transporters / Q000378:metabolism*; D000818:Animals; D018949:Antigens, CD1 / Q000378:metabolism*; D001692:Biological Transport; D002478:Cells, Cultured; D006801:Humans; D008213:Lymphocyte Activation; D008562:Membrane Glycoproteins / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D011994:Recombinant Proteins / Q000378:metabolism; D013601:T-Lymphocytes / Q000276:immunology; D014616:Vaccinia virus; D001613:beta 2-Microglobulin / Q000378:metabolism*
chemical_list: D000071181:ATP Binding Cassette Transporter, Subfamily B, Member 2; D000071450:ATP Binding Cassette Transporter, Subfamily B, Member 3; D018528:ATP-Binding Cassette Transporters; D018949:Antigens, CD1; D008562:Membrane Glycoproteins; D011994:Recombinant Proteins; C073119:TAP1 protein, human; C486171:Tap1 protein, mouse; C489516:Tap2 protein, mouse; D001613:beta 2-Microglobulin; C071692:TAP2 protein, human