Identification of Novel HLA-A*0201-Restricted CTL Epitopes in Chinese Vitiligo Patients

Abstract

Generalized vitiligo is an autoimmune disease characterized by melanocyte loss, which results in patchy depigmentation of skin and hair. Recent studies suggested the key role of CD8+T lymphocytes for mediating immune response in vitiligo through melanocyte differentiation antigens, including tyrosinase, gp100 and MelanA/Mart-1. However, the specific epitopes of these auto-antigens are still unknown. In our study, we predicted the possible HLA-A*0201-restricted nonapeptides overlaying the full-length amino acid sequences of these three known antigens and investigated the lymphocytes reactivity to these nonapeptides by Elispot assay. In addition, we evaluated the abilities of these nonapeptides to activate CD8+T cells. We screened out 5 possible epitopes originated from tyrosinase and gp100, numbered P28, P41, P112, P118 and P119. Among these 5 epitopes, notably, P28 and P119 played the dominant role in activating CTLs, with a significant increase in proliferation rate and Interferon-γ (IFN-γ) production of CD8+T cells. Nevertheless, antigen-specific T cell reactivity was not detected in MelanA/Mart-1 peptides. Our studies identified two novel epitopes originated from proteins of gp100 and tyrosinase, which may have implications for the development of immunotherapies for vitiligo.

Construction of a Recombinant OmpC Dominant Epitope-Based Vaccine Against Escherichia coli and Evaluation of Its Immunogenicity and Protective Immunity

“…CTL cell epitopes play an integral role in the adaptive immune response (20); and prediction methods include nHLAPred, IEDB, SYFPEITHI, and IMTECH (21)(22)(23). Similarly, the nHLAPred method has been used to predict CTL cell epitopes for Leishmania major-related candidate antigens and HIV Gag protein (10,23), and they showed high immunogenicity.…”

Identification of the Risk HLA-A Alleles and Autoantigen in Han Chinese Vitiligo Patients and the Association of CD8+T Cell Reactivity with Disease Characteristics

“…Following informed consent, information of patients’ characteristics, family history, disease activity, and area of the skin lesions were collected mainly by questionnaire. The selected vitiligo patients in this study did not have any systemic treatment (including immunosuppressive therapy or phototherapy) during at least 3 months, as described in our previous research [ 23 ].…”

“…We collected 25 mL to 30 mL heparinized blood samples and used the samples to isolate peripheral blood mononuclear cells (PBMCs). The isolations of PBMCs were performed by Ficoll gradient centrifugation (Dakewe, Beijing, China) as described in our previous study [ 23 ]. Red Blood Cell Lysis Buffer was used to resuspend PBMCs and remove the red blood cells.…”

“…ELISPOT assays were performed as described in our previous study [ 23 ]. PBMCs were unfrozen, washed, and incubated overnight in DAYOU medium (Dakewe, Beijing, China) at 37°C in 5% CO 2 .…”

“…The blue spots were counted using an ELISPOT Image Analyzer and software (Cell Technology Inc., Jessup, MD, USA). The spot forming cells (SFC) were defined as described in our previous research [ 23 ] as SFC=experimental group–irrelevant control group.…”