Abstract
Peptide loading by major histocompatibility complex (MHC) class II molecules occurs in the endocytic pathway and is critically dependent upon the function of the class II-related molecule human leucocyte antigen-DM (HLA-DM). We have previously shown that a tyrosine-based lysosomal targeting signal present in the cytoplasmic tail of DMB has the capacity to target HLA-DM to peptide-loading compartments in HeLa cells. Here we investigate the importance of this signal in directing HLA-DM to processing compartments in professional antigen-presenting cells. We reconstituted a DMB-negative B-lymphoblastoid cell line with native or targeting-deficient DMB and show that in the absence of its tyrosine signal, DMB-Y230A is as efficient as the wild-type molecule in inducing MHC class II SDS stable dimer formation; restoring expression of the conformation-dependent DR3 epitope 16:23; the removal of CLIP; and accessing lysosomal peptide-loading compartments. By transient transfection in HeLa cells we show that Ii is able to compensate for loss of DMB-encoded targeting information. These data imply that in cells expressing physiological levels of class II, Ii and DM, there is sufficient association with Ii to direct the majority of DM into the endocytic pathway. Thus MHC class II and HLA-DM may follow similar intracellular trafficking pathways on route to antigen-processing compartments.
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- Bakke O., Dobberstein B. MHC class II-associated invariant chain contains a sorting signal for endosomal compartments. Cell. 1990 Nov 16;63(4):707–716. doi: 10.1016/0092-8674(90)90137-4. [DOI] [PubMed] [Google Scholar]
 - Copier J., Kleijmeer M. J., Ponnambalam S., Oorschot V., Potter P., Trowsdale J., Kelly A. Targeting signal and subcellular compartments involved in the intracellular trafficking of HLA-DMB. J Immunol. 1996 Aug 1;157(3):1017–1027. [PubMed] [Google Scholar]
 - Fling S. P., Arp B., Pious D. HLA-DMA and -DMB genes are both required for MHC class II/peptide complex formation in antigen-presenting cells. Nature. 1994 Apr 7;368(6471):554–558. doi: 10.1038/368554a0. [DOI] [PubMed] [Google Scholar]
 - Johnson J. P., Meo T., Riethmüller G., Schendel D. J., Wank R. Direct demonstration of an HLA-DR allotypic determinant on the low molecular weight (beta) subunit using a mouse monoclonal antibody specific for DR3. J Exp Med. 1982 Jul 1;156(1):104–111. doi: 10.1084/jem.156.1.104. [DOI] [PMC free article] [PubMed] [Google Scholar]
 - Karlsson L., Péléraux A., Lindstedt R., Liljedahl M., Peterson P. A. Reconstitution of an operational MHC class II compartment in nonantigen-presenting cells. Science. 1994 Dec 2;266(5190):1569–1573. doi: 10.1126/science.7985028. [DOI] [PubMed] [Google Scholar]
 - Kropshofer H., Vogt A. B., Moldenhauer G., Hammer J., Blum J. S., Hämmerling G. J. Editing of the HLA-DR-peptide repertoire by HLA-DM. EMBO J. 1996 Nov 15;15(22):6144–6154. [PMC free article] [PubMed] [Google Scholar]
 - Lampson L. A., Levy R. Two populations of Ia-like molecules on a human B cell line. J Immunol. 1980 Jul;125(1):293–299. [PubMed] [Google Scholar]
 - Liljedahl M., Kuwana T., Fung-Leung W. P., Jackson M. R., Peterson P. A., Karlsson L. HLA-DO is a lysosomal resident which requires association with HLA-DM for efficient intracellular transport. EMBO J. 1996 Sep 16;15(18):4817–4824. [PMC free article] [PubMed] [Google Scholar]
 - Lindstedt R., Liljedahl M., Péléraux A., Peterson P. A., Karlsson L. The MHC class II molecule H2-M is targeted to an endosomal compartment by a tyrosine-based targeting motif. Immunity. 1995 Nov;3(5):561–572. doi: 10.1016/1074-7613(95)90127-2. [DOI] [PubMed] [Google Scholar]
 - Lotteau V., Teyton L., Peleraux A., Nilsson T., Karlsson L., Schmid S. L., Quaranta V., Peterson P. A. Intracellular transport of class II MHC molecules directed by invariant chain. Nature. 1990 Dec 13;348(6302):600–605. doi: 10.1038/348600a0. [DOI] [PubMed] [Google Scholar]
 - Marks M. S., Roche P. A., van Donselaar E., Woodruff L., Peters P. J., Bonifacino J. S. A lysosomal targeting signal in the cytoplasmic tail of the beta chain directs HLA-DM to MHC class II compartments. J Cell Biol. 1995 Oct;131(2):351–369. doi: 10.1083/jcb.131.2.351. [DOI] [PMC free article] [PubMed] [Google Scholar]
 - Morris P., Shaman J., Attaya M., Amaya M., Goodman S., Bergman C., Monaco J. J., Mellins E. An essential role for HLA-DM in antigen presentation by class II major histocompatibility molecules. Nature. 1994 Apr 7;368(6471):551–554. doi: 10.1038/368551a0. [DOI] [PubMed] [Google Scholar]
 - Pious D., Hawley P., Forrest G. Isolation and characterization of HL-A variants in cultured human lymphoid cells. Proc Natl Acad Sci U S A. 1973 May;70(5):1397–1400. doi: 10.1073/pnas.70.5.1397. [DOI] [PMC free article] [PubMed] [Google Scholar]
 - Ramachandra L., Kovats S., Eastman S., Rudensky A. Y. Variation in HLA-DM expression influences conversion of MHC class II alpha beta:class II-associated invariant chain peptide complexes to mature peptide-bound class II alpha beta dimers in a normal B cell line. J Immunol. 1996 Mar 15;156(6):2196–2204. [PubMed] [Google Scholar]
 - Riberdy J. M., Cresswell P. The antigen-processing mutant T2 suggests a role for MHC-linked genes in class II antigen presentation. J Immunol. 1992 Apr 15;148(8):2586–2590. [PubMed] [Google Scholar]
 - Riberdy J. M., Newcomb J. R., Surman M. J., Barbosa J. A., Cresswell P. HLA-DR molecules from an antigen-processing mutant cell line are associated with invariant chain peptides. Nature. 1992 Dec 3;360(6403):474–477. doi: 10.1038/360474a0. [DOI] [PubMed] [Google Scholar]
 - Sanderson F., Kleijmeer M. J., Kelly A., Verwoerd D., Tulp A., Neefjes J. J., Geuze H. J., Trowsdale J. Accumulation of HLA-DM, a regulator of antigen presentation, in MHC class II compartments. Science. 1994 Dec 2;266(5190):1566–1569. doi: 10.1126/science.7985027. [DOI] [PubMed] [Google Scholar]
 - Sanderson F., Thomas C., Neefjes J., Trowsdale J. Association between HLA-DM and HLA-DR in vivo. Immunity. 1996 Jan;4(1):87–96. doi: 10.1016/s1074-7613(00)80301-5. [DOI] [PubMed] [Google Scholar]
 - Sanderson F., Thomas C., Neefjes J., Trowsdale J. Association between HLA-DM and HLA-DR in vivo. Immunity. 1996 Jan;4(1):87–96. doi: 10.1016/s1074-7613(00)80301-5. [DOI] [PubMed] [Google Scholar]
 - Sloan V. S., Cameron P., Porter G., Gammon M., Amaya M., Mellins E., Zaller D. M. Mediation by HLA-DM of dissociation of peptides from HLA-DR. Nature. 1995 Jun 29;375(6534):802–806. doi: 10.1038/375802a0. [DOI] [PubMed] [Google Scholar]
 - Vogt A. B., Kropshofer H., Moldenhauer G., Hämmerling G. J. Kinetic analysis of peptide loading onto HLA-DR molecules mediated by HLA-DM. Proc Natl Acad Sci U S A. 1996 Sep 3;93(18):9724–9729. doi: 10.1073/pnas.93.18.9724. [DOI] [PMC free article] [PubMed] [Google Scholar]
 - Zhong G., Castellino F., Romagnoli P., Germain R. N. Evidence that binding site occupancy is necessary and sufficient for effective major histocompatibility complex (MHC) class II transport through the secretory pathway redefines the primary function of class II-associated invariant chain peptides (CLIP). J Exp Med. 1996 Nov 1;184(5):2061–2066. doi: 10.1084/jem.184.5.2061. [DOI] [PMC free article] [PubMed] [Google Scholar]
 - van Ham S. M., Grüneberg U., Malcherek G., Bröker I., Melms A., Trowsdale J. Human histocompatibility leukocyte antigen (HLA)-DM edits peptides presented by HLA-DR according to their ligand binding motifs. J Exp Med. 1996 Nov 1;184(5):2019–2024. doi: 10.1084/jem.184.5.2019. [DOI] [PMC free article] [PubMed] [Google Scholar]
 





