1. Academic Validation
  2. Combining metabolic and checkpoint therapy: 1,25-dihydroxyvitamin D₃ enhances the antiviral efficacy of anti-PD-1 in BVDV infection

Combining metabolic and checkpoint therapy: 1,25-dihydroxyvitamin D₃ enhances the antiviral efficacy of anti-PD-1 in BVDV infection

  • Vet Microbiol. 2026 Apr:315:110950. doi: 10.1016/j.vetmic.2026.110950.
Yang Li 1 Linru He 2 Peilong Li 3 Ruosi Chen 4 Fei Li 5 Lijia Yang 6 Yulong Zhou 7 Zecai Zhang 8 Shanshan Liu 9 Jianjun Zhao 10 Zhanbo Zhu 11 Yu Liu 12
Affiliations

Affiliations

  • 1 College of Animal Science and Veterinary Medicine, HeiLongJiang Bayi Agricultural University, Daqing 163319, China. Electronic address: [email protected].
  • 2 College of Animal Science and Veterinary Medicine, HeiLongJiang Bayi Agricultural University, Daqing 163319, China. Electronic address: [email protected].
  • 3 College of Animal Science and Veterinary Medicine, HeiLongJiang Bayi Agricultural University, Daqing 163319, China. Electronic address: [email protected].
  • 4 College of Animal Science and Veterinary Medicine, HeiLongJiang Bayi Agricultural University, Daqing 163319, China. Electronic address: [email protected].
  • 5 College of Animal Science and Veterinary Medicine, HeiLongJiang Bayi Agricultural University, Daqing 163319, China. Electronic address: [email protected].
  • 6 College of Animal Science and Veterinary Medicine, HeiLongJiang Bayi Agricultural University, Daqing 163319, China. Electronic address: [email protected].
  • 7 College of Animal Science and Veterinary Medicine, HeiLongJiang Bayi Agricultural University, Daqing 163319, China; Engineering Research Center of Prevention and Control of Cattle Diseases, Daqing, Heilongjiang 163319, China. Electronic address: [email protected].
  • 8 College of Animal Science and Veterinary Medicine, HeiLongJiang Bayi Agricultural University, Daqing 163319, China; Engineering Research Center of Prevention and Control of Cattle Diseases, Daqing, Heilongjiang 163319, China. Electronic address: [email protected].
  • 9 College of Animal Science and Veterinary Medicine, HeiLongJiang Bayi Agricultural University, Daqing 163319, China. Electronic address: [email protected].
  • 10 College of Animal Science and Veterinary Medicine, HeiLongJiang Bayi Agricultural University, Daqing 163319, China; Engineering Research Center of Prevention and Control of Cattle Diseases, Daqing, Heilongjiang 163319, China. Electronic address: [email protected].
  • 11 College of Animal Science and Veterinary Medicine, HeiLongJiang Bayi Agricultural University, Daqing 163319, China; Engineering Research Center of Prevention and Control of Cattle Diseases, Daqing, Heilongjiang 163319, China; Key Laboratory of Bovine Disease Control in Northeast China, Ministry of Agriculture and Rural Affairs, Daqing 163319, China. Electronic address: [email protected].
  • 12 College of Animal Science and Veterinary Medicine, HeiLongJiang Bayi Agricultural University, Daqing 163319, China; Engineering Research Center of Prevention and Control of Cattle Diseases, Daqing, Heilongjiang 163319, China; Key Laboratory of Bovine Disease Control in Northeast China, Ministry of Agriculture and Rural Affairs, Daqing 163319, China. Electronic address: [email protected].
Abstract

Bovine viral diarrhea virus (BVDV) Infection induces severe immunosuppression and peripheral blood lymphopenia, driven by PD-1/PD-L1-mediated T cell exhaustion. Emerging evidence highlights 1,25-dihydroxyvitamin D₃ (1,25(OH)₂D₃, VD), the active metabolite of vitamin D, as a critical modulator of Antiviral immunity. However, its interplay with PD-1 signaling in BVDV pathogenesis remains unexplored. This study investigated the therapeutic potential of VD alone or combined with PD-1 blockade in a murine BVDV Infection model. We found that BVDV Infection significantly reduced serum and intracellular concentrations of VD. Supplementation with VD effectively improved these levels, downregulated PD-1/PD-L1 expression, reduced lymphopenia, and reduced CD8+ T cell Apoptosis. While both monotherapies showed benefits, their combination yielded superior outcomes. The combined therapy significantly enhanced viral clearance, improved pathological changes in spleen and duodenum, and enhanced CD8⁺ T cell proliferation and IFN-γ production. Mechanistically, the combination uniquely upregulated key anti-apoptotic signaling molecules (p-Akt, p-mTOR, p-ERK) in CD8⁺ T cells. Notably, therapeutic efficacy differed between cytopathic (CP) and non-cytopathic (NCP) biotypes, with PD-1 blockade showing greater dependency in CP Infection. These findings highlight the therapeutic potential of targeting both metabolic dysregulation (via VD) and immune checkpoint inhibition (via PD-1 blockade) to combat BVDV-induced immunosuppression. This dual strategy may offer a novel approach for treating viral infections characterized by metabolic-viral-immune interplay.

Keywords

1; 25-dihydroxyvitamin D₃; Bovine viral diarrhea virus; CD8(+) T cell; Programmed death-1; T cell exhaustion.

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