phaidra.vetmeduni.ac.at o:2084 DOI 10.3390/v14091891 Identification of MHC-I-Presented Porcine Respiratory and Reproductive Syndrome Virus (PRRSV) Peptides Reveals Immunogenic Epitopes within Several Non-Structural Proteins Recognized by CD8+ T Cells Porcine reproductive and respiratory syndrome virus (PRRSV) is one of the most relevant porcine pathogens worldwide. Active control of the disease relies on modified live virus vaccines (MLVs), as most inactivated vaccines provide very limited protection. Neutralizing antibodies occur late in infection; therefore, CD8+ T cells are considered important correlates of protection and are a frequent focus of investigation. Our aim was to identify viral peptides naturally bound by the class I major histocompatibility complex (MHC-I) and to confirm their ability to stimulate CD8+ T cells. For this purpose, we immunoprecipitated MHC-I/peptide complexes of PRRSV (strain AUT15-33) -infected cells (SLA-I Lr-Hp 35.0/24 mod) to isolate the viral epitopes and analyzed them with liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). Furthermore, we employed these identified peptides to stimulate peripheral blood mononuclear cells (PBMCs) of previously PRRSV-infected pigs and measured the PRRSV-specific CD8+ T-cell response with an intracellular cytokine staining (ICS). Our data revealed that PRRSV non-structural proteins (NSPs), encoded in open reading frame 1a and 1b (ORF1), present the major source of MHC-I-presented peptides. Additionally, we show that our identified epitopes are able to trigger IFNγ responses in vitro. These findings are a basis for understanding the proteasomal degradation of PRRSV proteins, the cellular ability to display them via MHC-I, and their potential to restimulate CD8+ T cells. eng Swine Leukocyte Antigen; Ifn-Gamma; Replication; Challenge; Evolution; Immunity 2023-09-08T11:58:51.197Z LOMv1.0 Author BEGIN:VCARD VERSION:3.0 N:Mötz;Marlene; FN:Marlene Mötz X-ORCID:https://orcid.org/0000-0001-7929-5662 END:VCARD BEGIN:VCARD VERSION:3.0 N:Rümenapf;Till; FN:Till Rümenapf X-ORCID:https://orcid.org/0000-0002-2951-7471 END:VCARD BEGIN:VCARD VERSION:3.0 N:Saalmüller;Armin; FN:Armin Saalmüller X-ORCID:https://orcid.org/0000-0002-7703-3252 END:VCARD BEGIN:VCARD VERSION:3.0 N:Riedel;Christiane; FN:Christiane Riedel X-ORCID:https://orcid.org/0000-0002-4349-996X END:VCARD BEGIN:VCARD VERSION:3.0 N:Müller;André C.; FN:André C. Müller END:VCARD BEGIN:VCARD VERSION:3.0 N:Ladinig;Andrea; FN:Andrea Ladinig X-ORCID:https://orcid.org/0000-0001-5037-7269 END:VCARD BEGIN:VCARD VERSION:3.0 N:Seitz;Kerstin; FN:Kerstin Seitz X-ORCID:https://orcid.org/0000-0003-2852-5047 END:VCARD BEGIN:VCARD VERSION:3.0 N:Kiesler;Alexandra; FN:Alexandra Kiesler X-ORCID:https://orcid.org/0000-0001-8840-033X END:VCARD BEGIN:VCARD VERSION:3.0 N:Fontaine;Frederic; FN:Frederic Fontaine END:VCARD BEGIN:VCARD VERSION:3.0 N:Duckova;Tereza; FN:Tereza Duckova END:VCARD BEGIN:VCARD VERSION:3.0 N:Hammer;Sabine E.; FN:Sabine E. Hammer X-ORCID:https://orcid.org/0000-0003-1475-3938 END:VCARD BEGIN:VCARD VERSION:3.0 N:Stas;Melissa R.; FN:Melissa R. Stas X-ORCID:https://orcid.org/0000-0002-7996-179X END:VCARD https://w3id.org/kim/hcrt/scheme https://w3id.org/kim/hcrt/text Textdokument Text LOMv1.0 yes https://creativecommons.org/licenses/by/4.0 application/pdf 565478 https://phaidra.vetmeduni.ac.at/o:2084 https://phaidra.vetmeduni.ac.at/api/object/o:2084/thumbnail LOMv1.0 discipline