Shimizu M, Yamada S, Kawashima K, Ohashi S, Shimizu S, Ogawa T
National Institute of Animal Health, Ibaraki, Japan.
Vet Immunol Immunopathol. 1996 Mar;50(1-2):19-27. doi: 10.1016/0165-2427(95)05494-4.
Abnormal changes of T-cell subpopulation were observed in the peripheral blood lymphocytes of pigs infected with porcine reproductive and respiratory syndrome (PRRS) virus. Pigs with naturally occurring PRRS revealed increases in CD2+ and CD8+ cells, and decreases in CD4+ cells and the ratios of CD4+/CD8+ cells. Specific-pathogen-free pigs inoculated with PRRS virus showed remarkable decreases in total lymphocytes, CD4+ and CD2+ cells on Postinoculation Day (PID) 3. The decline of CD4+ cells continued for at least 14 days, while CD2+ cells showed a tendency to increase thereafter. On the other hand,CD8+ cells slightly decreased in number on PID 3, and then increased remarkably; their number was significantly larger on PIDs 28 and 35 than on PID 0. The ratios of CD4+/CD8+ cells were significantly low between PIDs 3 and 28 as compared with PID 0. However, there were no differences in thymocyte subpopulations between infected and non-infected pigs, suggesting that the PRRS virus does not modulate intrathymic T-cell differentiation. In an experiment with peripheral blood mononuclear cell cultures, PRRS virus caused neither alteration of T-cell subpopulations nor cell proliferation, suggesting that the virus is not cytotoxic for CD4+ cells and not mitogenic for CD8+ cells.
在感染猪繁殖与呼吸综合征（PRRS）病毒的猪外周血淋巴细胞中观察到T细胞亚群的异常变化。自然感染PRRS的猪CD2⁺和CD8⁺细胞增加，CD4⁺细胞和CD4⁺/CD8⁺细胞比值降低。接种PRRS病毒的无特定病原体猪在接种后第3天（PID 3）总淋巴细胞、CD4⁺和CD2⁺细胞显著减少。CD4⁺细胞的减少持续至少14天，而CD2⁺细胞此后呈增加趋势。另一方面，CD8⁺细胞在PID 3时数量略有减少，然后显著增加；在PID 28和35时其数量明显多于PID 0时。与PID 0相比，PID 3至28期间CD4⁺/CD8⁺细胞比值显著降低。然而，感染猪和未感染猪的胸腺细胞亚群没有差异，这表明PRRS病毒不会调节胸腺内T细胞分化。在外周血单个核细胞培养实验中，PRRS病毒既未引起T细胞亚群改变，也未引起细胞增殖，这表明该病毒对CD4⁺细胞无细胞毒性，对CD8⁺细胞无促有丝分裂作用。
