title: Uptake of HLA Alloantigens via CD89 and CD206 Does Not Enhance Antigen Presentation by Indirect Allorecognition.
abstract: In organ transplantation, alloantigens are taken up by antigen presenting cells and presented via the indirect pathway to T-cells which in turn can induce allograft rejection. Monitoring of these T-cells is of major importance; however no reliable assay is available to routinely monitor indirect allorecognition. Recently we showed that HLA monomers can be successfully used to monitor indirect allorecognition. Targeting antigens to endocytic receptors on antigen presenting cells may further enhance the presentation of antigens via HLA class II and improve the efficiency of this assay. In the current study we explored targeting of HLA monomers to either CD89 expressing monocytes or mannose receptor expressing dendritic cells. Monomer-antibody complexes were generated using biotin-labeled monomers and avidin labeling of the antibodies. We demonstrate that targeting the complexes to these receptors resulted in a dose-dependent HLA class II mediated presentation to a T-cell clone. The immune-complexes were efficiently taken up and presented to T-cells. However, the level of T-cell reactivity was similar to that when only exogenous antigen was added. We conclude that HLA-A2 monomers targeted for presentation through CD89 on monocytes or mannose receptor on dendritic cells lead to proper antigen presentation but do not enhance indirect allorecognition via HLA-DR.
authors.affiliation: Department of Nephrology, Leiden University Medical Center (LUMC), 2333 ZA Leiden, Netherlands.
authors.forename: Eytan
authors.initials: E
authors.lastname: Breman
authors.affiliation: Department of Nephrology, Leiden University Medical Center (LUMC), 2333 ZA Leiden, Netherlands.
authors.forename: Jurjen M
authors.initials: JM
authors.lastname: Ruben
authors.affiliation: Department of Immunohematology and Blood Transfusion, LUMC, 2333 ZA Leiden, Netherlands.
authors.forename: Kees L
authors.initials: KL
authors.lastname: Franken
authors.affiliation: Department of Hematology, LUMC, 2333 ZA Leiden, Netherlands.
authors.forename: Mirjam H M
authors.initials: MH
authors.lastname: Heemskerk
authors.affiliation: Department of Immunohematology and Blood Transfusion, LUMC, 2333 ZA Leiden, Netherlands.
authors.forename: Dave L
authors.initials: DL
authors.lastname: Roelen
authors.affiliation: Department of Immunohematology and Blood Transfusion, LUMC, 2333 ZA Leiden, Netherlands.
authors.forename: Frans H
authors.initials: FH
authors.lastname: Claas
authors.affiliation: Department of Nephrology, Leiden University Medical Center (LUMC), 2333 ZA Leiden, Netherlands.
authors.forename: Cees
authors.identifier: 0000-0002-6257-0899
authors.initials: C
authors.lastname: van Kooten
mesh_terms: D017951:Antigen Presentation; D000936:Antigen-Antibody Complex; D015703:Antigens, CD / Q000235:genetics / Q000276:immunology*; D003713:Dendritic Cells / Q000276:immunology; D015789:HLA-A2 Antigen / Q000235:genetics / Q000276:immunology*; D006684:HLA-DR Antigens / Q000276:immunology; D006801:Humans; D007519:Isoantigens / Q000276:immunology*; D037181:Lectins, C-Type / Q000235:genetics / Q000276:immunology*; D008213:Lymphocyte Activation; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins / Q000235:genetics / Q000276:immunology*; D009000:Monocytes / Q000276:immunology; D011956:Receptors, Cell Surface / Q000235:genetics / Q000276:immunology*; D011961:Receptors, Fc / Q000235:genetics / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000936:Antigen-Antibody Complex; D015703:Antigens, CD; C036832:Fc(alpha) receptor; D015789:HLA-A2 Antigen; D006684:HLA-DR Antigens; D007519:Isoantigens; D037181:Lectins, C-Type; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins; D011956:Receptors, Cell Surface; D011961:Receptors, Fc