Identification of MHC-I presented porcine respiratory and re-productive syndrome virus (PRRSV) peptides reveals immu-nogenic epitopes within several non-structural proteins recog-nized by CD8+ T cells

ABSTRACT: Porcine reproductive and respiratory syndrome virus (PRRSV) is one of the most relevant por-cine 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 stimu-late CD8+ T cells. For this purpose, we immunoprecipitated MHC-I/peptide complexes of PRRSV (strain AUT15-33) -infected cells (SLA-I Lr-Hp 35.0/24mod) to isolate the viral epitopes and ana-lyzed them with liquid chromatography coupled to mass spectrometry (LC-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 re-sponse with an intracellular cytokine staining (ICS). Our data reveals 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 trig-ger IFNγ responses in vitro. These findings are a basis for understanding the proteasomal degra-dation of PRRSV proteins, the cellular ability to display them via MHC-I, and their potential to restimulate CD8+ T cells.

INSTRUMENT(S): Orbitrap Fusion Lumos

ORGANISM(S): Sus Scrofa Domesticus (domestic Pig)

TISSUE(S): Primary Cell, Macrophage

SUBMITTER: Marlene Mötz  

LAB HEAD: Till Rümenapf

PROVIDER: PXD035499 | Pride | 2022-10-14

REPOSITORIES: Pride