Autoreactive cytotoxic CD8 T-cells (CTLs) play a key pathogenic role in the destruction of insulin-producing beta-cells resulting in type 1 diabetes. However, knowledge regarding their targets is... Show moreAutoreactive cytotoxic CD8 T-cells (CTLs) play a key pathogenic role in the destruction of insulin-producing beta-cells resulting in type 1 diabetes. However, knowledge regarding their targets is limited, restricting the ability to monitor the course of the disease and immune interventions. In a multi-step discovery process to identify novel CTL epitopes in human preproinsulin (PPI), PPI was digested with purified human proteasomes, and resulting COOH-fragments aligned with algorithm-predicted HLA-binding peptides to yield nine potential HLA-A1, -A2, -A3 or -B7-restricted candidates. An UV-exchange method allowed the generation of a repertoire of multimers including low-affinity HLA-binding peptides. These were labeled with quantum dot-fluorochromes and encoded in a combinatorial fashion, allowing parallel and sensitive detection of specific, low-avidity T-cells. Significantly increased frequencies of T-cells against four novel PPI epitopes (PPI(4-13)/B7, PPI(29-38)/A2, PPI(76-84)/A3 and PPI(79-88)/A3) were detected in stored blood of patients with recent onset diabetes but not in controls. Changes in frequencies of circulating CD8 T-cells against these novel epitopes were detected in blood of islet graft recipients at different time points after transplantation, which correlated with clinical outcome. In conclusion, our novel strategy involving a sensitive multiplex detection technology and requiring minimal volumes of stored blood represents a major improvement in the direct ex-vivo characterization and enumeration of immune cells in the pathogenesis of type 1 diabetes. Show less
OBJECTIVE Type 1 diabetes results from selective T-cell-mediated destruction of the insulin-producing beta-cells in the pancreas. In this process, islet epitope-specific CD8(+) T-cells play a... Show moreOBJECTIVE Type 1 diabetes results from selective T-cell-mediated destruction of the insulin-producing beta-cells in the pancreas. In this process, islet epitope-specific CD8(+) T-cells play a pivotal role. Thus, monitoring of multiple islet-specific CD8(+) T-cells may prove to be valuable for measuring disease activity, progression, and intervention. Yet, conventional detection techniques (ELISPOT and HLA tetramers) require many cells and are relatively insensitive. RESEARCH DESIGN AND METHODS Here, we used a combinatorial quantum dot major histocompatibility complex multimer technique to simultaneously monitor the presence of HLA-A2 restricted insulin B(10-18), prepro-insulin (PPI)(15-24), islet antigen (IA)-2(797-805), GAD65(114-123), islet-specific glucose-6-phosphatase catalytic subunit-related protein (IGRP)(265-273), and prepro islet amyloid polypeptide (ppIAPP)(5-13)-specific CD8(+) T-cells in recent-onset diabetic patients, their siblings, healthy control subjects, and islet cell transplantation recipients. RESULTS Using this kit, islet autoreactive CD8(+) T-cells recognizing insulin B(10-18), IA-2(797-805), and IGRP(265-273) were shown to be frequently detectable in recent-onset diabetic patients but rarely in healthy control subjects; PPI(15-24) proved to be the most sensitive epitope. Applying the "Diab-Q-kit" to samples of islet cell transplantation recipients allowed detection of changes of autoreactive T-cell frequencies against multiple islet cell-derived epitopes that were associated with disease activity and correlated with clinical outcome. CONCLUSIONS A kit was developed that allows simultaneous detection of CD8(+) T-cells reactive to multiple HLA-A2-restricted beta-cell epitopes requiring limited amounts of blood, without a need for in vitro culture, that is applicable on stored blood samples. Show less
OBJECTIVE-Type I diabetes results from selective T-cell-mediated destruction of the insulin-producing beta-cells in the pancreas. In this process, islet epitope-specific CD8(+) T-cells play a... Show moreOBJECTIVE-Type I diabetes results from selective T-cell-mediated destruction of the insulin-producing beta-cells in the pancreas. In this process, islet epitope-specific CD8(+) T-cells play a pivotal role. Thus, monitoring of multiple islet-specific CD8(+) T-cells may prove to be valuable for measuring disease activity, progression, and intervention. Yet, conventional detection techniques (ELISPOT and HLA tetramers) require many cells and are relatively insensitive. RESEARCH DESIGN AND METHODS-Here, we used a combinatorial quantum dot major histocompatibility complex multimer technique to simultaneously monitor the presence of HLA-A2 restricted insulin B10-18, prepro-insulin (PPI)(15-24), islet antigen (IA)-2(797-805), GAD65(114-123) islet-specific glucose-6-phosphatase catalytic subunit-related protein (IGRP)(265-973), and prepro islet amyloid polypeptide (ppIAPP)(5-13)-specific CD8(+) T-cells in recent-onset diabetic patients, their siblings, healthy control subjects, and islet cell transplantation recipients. RESULTS-Using this kit, islet autoreactive CD8(+) T-cells recognizing insulin B10-18, IA-2(797-805), and IGRP(265-273) were shown to be frequently detectable in recent-onset diabetic patients but rarely in healthy control subjects; PPI15-24 proved to be the most sensitive epitope. Applying the "Diab-Q-kit" to samples of islet cell transplantation recipients allowed detection of changes of autoreactive T-cell frequencies against multiple islet cell-derived epitopes that were associated with disease activity and correlated with clinical outcome. CONCLUSIONS-A kit was developed that allows simultaneous detection of CD8(+) T-cells reactive to multiple HLA-A2-restricted beta-cell epitopes requiring limited amounts of blood, without a need for in vitro culture, that is applicable on stored blood samples. Diabetes 59:1721-1730, 2010 Show less
This thesis focuses on the generation of MHC ligands and their use in analyzing T cell immunity, both in mouse and men. It is roughly split into two sections: the first part deals specifically with... Show moreThis thesis focuses on the generation of MHC ligands and their use in analyzing T cell immunity, both in mouse and men. It is roughly split into two sections: the first part deals specifically with the rules governing the generation of MHC ligands, while the second part describes technological advances in the use of these MHC ligands to analyze T cell immunity. The first part of this thesis starts with an introduction on antigen presentation, covering both the different mechanisms through which epitopes are generated and the process by which epitopes are presented to T cells. Emphasis lies on the discoveries in this field of the last decade. This introduction is followed by two chapters on the generation of antigenic epitopes. Chapter two describes the analysis of protease activity in the endocytic pathway, while chapter three investigates the antigenic source of epitopes generated during cross-presentation. The second part of this thesis starts with a review on the status of MHC multimer technology as a tool to analyze antigen specific T cell populations. Chapter five then describes a high-throughput approach to generate a vast array of different peptide-MHC complexes for several human MHC alleles, allowing for faster and more complex applications of MHC multimer technology. In the next chapter, the peptide-exchange technology of chapter 5 is used for the development of another novel strategy: multidimensional encoding of peptide-MHC complexes. This chapter describes the development, validation and use of this encoding technique that allows the parallel detection of antigen-specific T cell responses of up to 25 T cell populations in one single sample. Finally, this thesis concludes with a summary and discussion chapter, giving a short overview of the presented data and discussing its relevance in the field of antigen presentation. Show less
Lennon-Dumenil, A.M.; Bakker, A.H.; Maehr, R.; Fiebiger, E.; Overkleeft, H.S.; Rosemblatt, M.; ... ; Lagaudriere-Gesbert, C. 2002
