title: Screening and identification of severe acute respiratory syndrome-associated coronavirus-specific CTL epitopes.
abstract: Severe acute respiratory syndrome (SARS) is a highly contagious and life-threatening disease that emerged in China in November 2002. A novel SARS-associated coronavirus was identified as its principal etiologic agent; however, the immunopathogenesis of SARS and the role of special CTLs in virus clearance are still largely uncharacterized. In this study, potential HLA-A*0201-restricted spike (S) and nucleocapsid protein-derived peptides were selected from an online database and screened for potential CTL epitopes by in vitro refolding and T2 cell-stabilization assays. The antigenicity of nine peptides which could refold with HLA-A*0201 molecules was assessed with an IFN-gamma ELISPOT assay to determine the capacity to stimulate CTLs from PBMCs of HLA-A2(+) SARS-recovered donors. A novel HLA-A*0201-restricted decameric epitope P15 (S411-420, KLPDDFMGCV) derived from the S protein was identified and found to localize within the angiotensin-converting enzyme 2 receptor-binding region of the S1 domain. P15 could significantly enhance the expression of HLA-A*0201 molecules on the T2 cell surface, stimulate IFN-gamma-producing CTLs from the PBMCs of former SARS patients, and induce specific CTLs from P15-immunized HLA-A2.1 transgenic mice in vivo. Furthermore, significant P15-specific CTLs were induced from HLA-A2.1-transgenic mice immunized by a DNA vaccine encoding the S protein; suggesting that P15 was a naturally processed epitope. Thus, P15 may be a novel SARS-associated coronavirus-specific CTL epitope and a potential target for characterization of virus control mechanisms and evaluation of candidate SARS vaccines.
authors.affiliation: Center for Molecular Immunology and Center for Molecular Virology, Institute of Microbiology, Chinese Academy of Sciences (CAS), Beijing, The People's Republic of China.
authors.forename: Minghai
authors.initials: M
authors.lastname: Zhou
authors.forename: Dongping
authors.initials: D
authors.lastname: Xu
authors.forename: Xiaojuan
authors.initials: X
authors.lastname: Li
authors.forename: Hongtao
authors.initials: H
authors.lastname: Li
authors.forename: Ming
authors.initials: M
authors.lastname: Shan
authors.forename: Jiaren
authors.initials: J
authors.lastname: Tang
authors.forename: Min
authors.initials: M
authors.lastname: Wang
authors.forename: Fu-Sheng
authors.initials: FS
authors.lastname: Wang
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Zhu
authors.forename: Hua
authors.initials: H
authors.lastname: Tao
authors.forename: Wei
authors.initials: W
authors.lastname: He
authors.forename: Po
authors.initials: P
authors.lastname: Tien
authors.forename: George F
authors.initials: GF
authors.lastname: Gao
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D000086462:Coronavirus Nucleocapsid Proteins; D004797:Enzyme-Linked Immunosorbent Assay; D018984:Epitopes, T-Lymphocyte / Q000276:immunology* / Q000302:isolation & purification / Q000378:metabolism; D015234:HLA-A Antigens / Q000096:biosynthesis / Q000378:metabolism; D015789:HLA-A2 Antigen; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism; D007424:Intracellular Fluid / Q000276:immunology / Q000378:metabolism / Q000821:virology; D007963:Leukocytes, Mononuclear / Q000276:immunology / Q000821:virology; D008213:Lymphocyte Activation / Q000276:immunology; D008562:Membrane Glycoproteins / Q000008:administration & dosage / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D019590:Nucleocapsid Proteins / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism; D010446:Peptide Fragments / Q000008:administration & dosage / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism; D011485:Protein Binding / Q000276:immunology; D045473:Severe acute respiratory syndrome-related coronavirus / Q000276:immunology* / Q000302:isolation & purification / Q000378:metabolism; D064370:Spike Glycoprotein, Coronavirus; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology* / Q000378:metabolism / Q000821:virology*; D019444:Vaccines, DNA / Q000008:administration & dosage / Q000276:immunology; D014759:Viral Envelope Proteins / Q000008:administration & dosage / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism
chemical_list: D000086462:Coronavirus Nucleocapsid Proteins; D018984:Epitopes, T-Lymphocyte; D015234:HLA-A Antigens; C435939:HLA-A*02:01 antigen; D015789:HLA-A2 Antigen; D008562:Membrane Glycoproteins; D019590:Nucleocapsid Proteins; D010446:Peptide Fragments; D064370:Spike Glycoprotein, Coronavirus; D019444:Vaccines, DNA; D014759:Viral Envelope Proteins; C578557:spike glycoprotein, SARS-CoV; C578553:spike protein, mouse hepatitis virus; D007371:Interferon-gamma