Korean J Vet Res.  2018 Mar;58(1):9-16. 10.14405/kjvr.2018.58.1.9.

Preliminary assessment of correlation between T-lymphocyte responses and control of porcine reproductive and respiratory syndrome virus (PRRSV) in piglets born after in-utero infection of a type 2 PRRSV

• Cha SH
• Bandaranayaka-Mudiyanselage C
• Bandaranayaka-Mudiyanselage CB
• Ajiththos
• Yoon KJ
• Gibson KA
• Yu JE
• Cho IS
• Lee SS
• Chung CJ

• KMID: 2437672
• DOI: http://doi.org/10.14405/kjvr.2018.58.1.9

Abstract

A preliminary study into the protective mechanisms of adaptive immunity against porcine reproductive and respiratory syndrome virus (PRRSV) in piglets (n = 9) born to a gilt challenged intranasally with a type-2 PRRSV. Immune parameters (neutralizing antibodies, CD3⁺CD4⁺, CD3⁺CD8⁺, CD3⁺CD4⁺CD8⁺ T-lymphocytes, and PRRSV-specific interferon (IFN)-γ secreting T-lymphocytes) were compared with infection parameters (macro- and microscopic lung lesion, and PRRSV-infected porcine alveolar macrophages (CD172α⁺PRRSV-N⁺ PAM) as well as with plasma and lymphoid tissue viral loads. Percentages of three T-lymphocyte phenotypes in 14-days post-birth (dpb) peripheral blood mononuclear cell (PBMC) had significant negative correlations with percentages of CD172α⁺PRRSV-N⁺ PAM (p < 0.05) as well as with macroscopic lung lesion (p < 0.01). Plasma and tissue viral loads had significant (p < 0.05) negative correlations with CD3⁺CD4⁺CD8⁺ T-lymphocyte percentage in PBMC. Frequencies of CD3⁺CD8⁺ and CD3⁺CD4⁺ T-lymphocytes in 14-dpb PBMC had significant negative correlations with of lymph node (p = 0.04) and lung (p = 0.002) viral loads. IFN-γ-secreting T-lymphocytes frequency had a significant negative correlation with gross lung lesion severity (p = 0.002). However, neutralizing antibody titers had no significant negative correlation (p > 0.1) with infection parameters. The results indicate that T-lymphocytes contribute to controlling PRRSV replication in young piglets born after in-utero infection.

Keyword

T-lymphocyte; neutralizing antibodies; porcine reproductive and respiratory syndrome virus

MeSH Terms

Adaptive Immunity
Antibodies
Antibodies, Neutralizing
Interferons
Lung
Lymph Nodes
Lymphoid Tissue
Macrophages, Alveolar
Phenotype
Plasma
Porcine Reproductive and Respiratory Syndrome*
Porcine respiratory and reproductive syndrome virus*
T-Lymphocytes*
Viral Load
Antibodies
Antibodies, Neutralizing
Interferons