There is growing interest in HLA-E-restricted T-cell responses as a possible novel, highly conserved, vaccination targets in the context of infectious and malignant diseases. The developing field... Show moreThere is growing interest in HLA-E-restricted T-cell responses as a possible novel, highly conserved, vaccination targets in the context of infectious and malignant diseases. The developing field of HLA multimers for the detection and study of peptide-specific T cells has allowed the in-depth study of TCR repertoires and molecular requirements for efficient antigen presentation and T-cell activation. In this study, we developed a method for efficient peptide thermal exchange on HLA-E monomers and multimers allowing the high-throughput production of HLA-E multimers. We optimized the thermal-mediated peptide exchange, and flow cytometry staining conditions for the detection of TCR and NKG2A/CD94 receptors, showing that this novel approach can be used for high-throughput identification and analysis of HLA-E-binding peptides which could be involved in T-cell and NK cell-mediated immune responses. Importantly, our analysis of NKG2A/CD94 interaction in the presence of modified peptides led to new molecular insights governing the interaction of HLA-E with this receptor. In particular, our results reveal that interactions of HLA-E with NKG2A/CD94 and the TCR involve different residues. Altogether, we present a novel HLA-E multimer technology based on thermal-mediated peptide exchange allowing us to investigate the molecular requirements for HLA-E/peptide interaction with its receptors. Show less
Organ-specific autoimmunity is often characterized by autoantibodies targeting proteins expressed in the affected tissue. A subgroup of autoimmunopathies has recently emerged that is characterized... Show moreOrgan-specific autoimmunity is often characterized by autoantibodies targeting proteins expressed in the affected tissue. A subgroup of autoimmunopathies has recently emerged that is characterized by predominant autoantibodies of the IgG4 subclass (IgG4-autoimmune diseases; IgG4-AID). This group includes pemphigus vulgaris, thrombotic thrombocytopenic purpura, subtypes of autoimmune encephalitis, inflammatory neuropathies, myasthenia gravis and membranous nephropathy. Although the associated autoantibodies target specific antigens in different organs and thus cause diverse syndromes and diseases, they share surprising similarities in genetic predisposition, disease mechanisms, clinical course and response to therapies. IgG4-AID appear to be distinct from another group of rare immune diseases associated with IgG4, which are the IgG4-related diseases (IgG4-RLD), such as IgG4-related which have distinct clinical and serological properties and are not characterized by antigen-specific IgG4. Importantly, IgG4-AID differ significantly from diseases associated with IgG1 autoantibodies targeting the same organ. This may be due to the unique functional characteristics of IgG4 autoantibodies (e.g. anti-inflammatory and functionally monovalent) that affect how the antibodies cause disease, and the differential response to immunotherapies of the IgG4 producing B cells/plasmablasts. These clinical and pathophysiological clues give important insight in the immunopathogenesis of IgG4-AID. Understanding IgG4 immunobiology is a key step towards the development of novel, IgG4 specific treatments. In this review we therefore summarize current knowledge on IgG4 regulation, the relevance of class switching in the context of health and disease, describe the cellular mechanisms involved in IgG4 production and provide an overview of treatment responses in IgG4-AID. Show less
A single model system for integrative studies on multiple facets of antigen presentation is lacking. PAKC is a novel panel of ten cell lines knocked out for individual components of the HLA class I... Show moreA single model system for integrative studies on multiple facets of antigen presentation is lacking. PAKC is a novel panel of ten cell lines knocked out for individual components of the HLA class I antigen presentation pathway. PAKC will accelerate HLA-I research in the fields of oncology, infectiology, and autoimmunity. Show less
The involvement of Minor histocompatibility antigens (MiHA) in the graft versus tumor is described about three decades ago. Nowadays, there are many evidences that, after HLA-matched allogeneic... Show moreThe involvement of Minor histocompatibility antigens (MiHA) in the graft versus tumor is described about three decades ago. Nowadays, there are many evidences that, after HLA-matched allogeneic hematopoietic stem cell transplantation (HSCT) MiHA specific T cells mediate both graft versus leukemia (GVL) reactivity and graft versus host disease (GVHD), which is a major cause of morbidity and mortality. To identify MiHA we decided to establish a new strategy based on the bone fide eluted ligandome. Then we developed a database dedicated for identification of polymorphic peptides called human short peptide variation database (HSPVdb). To identify potential MiHA among the huge number of polymorphic peptides eluted from HLA-A*0201 or HLA-B*0702 we selected the top 25 MiHA candidates identified in chapter 2. From this set of data we could validate 2 novel potential MiHA being (LB-CLYBL-1Y & LB-TEP1-1S). To find out at which stages the great_est losses occurred, we developed a method to be able to quantitate MiHA on the cell surface. In addition we studied the phenomenon of the unidirectional T cell responses against MiHA. We studied in depth the presentation of non-canonical long peptides in HLA-A*0201 molecules. Show less
Heemst, J. van; Huizinga, T.J.W.; Woude, D. van der; Toes, R.E.M. 2015
The minor histocompatibility (mH) antigen HA-1 is expressed by cells of hematopoietic origin only. The sequences of the immunogenic CTL epitope VLHDDLLEA (HA-1H) and the VLRDDLLEA (HA-1R)... Show moreThe minor histocompatibility (mH) antigen HA-1 is expressed by cells of hematopoietic origin only. The sequences of the immunogenic CTL epitope VLHDDLLEA (HA-1H) and the VLRDDLLEA (HA-1R) counterpart differ by one aminoacid. Selectively infusing HA-1H specific donor cytotoxic T cells may mediate a strong GvL effect with a low risk for GvHD. However, this HA-1H specific immunotherapy is currently feasible only for HLA-A2 HA-1HH or HA-1HR patients who relapsed following an SCT from an HLA-A2 HA-1RR donor. In addition, the therapy is not guaranteed for all of these patients. For instance, the anonymous umbilical cord blood (UCB) donors cannot be traced again for use of DLI or adoptive immunotherapy following transplantation. Moreover, the success rate of HA-1H specific HLA2 restricted CTL induction is donor dependent. This thesis describes the following important features, which may lead to extension of the patient population that may benefit from HA-1 specific immunotherapy: - The instable natural presentation of HA-1R in HLA-A2. - A novel HLA-B60 restricted HA-1H epitope. - Hematopoietic-specific CTLs from UCB directed against HA-1H in the context of HLA-A2. - HA-1 specific TCR transfer directing non- HA-1 TCR expressing adult and UCB CD8+ T cells to hematopoietic-specific cytolytic activity. Show less
