In our previous study, we established a unique porcine macrophage cell line, immortalized porcine kidney-derived macrophages (IPKM). The purpose of the present study was to further elucidate the characteristics of IPKM. CD163 is a scavenger receptor for the hemoglobin-haptoglobin complex and is used as a phenotypic marker of anti-inflammatory M2 macrophages. The expression of CD163 is enhanced by dexamethasone (DEX), a potent steroidal anti-inflammatory drug, in human and rodent macrophages in vitro. Therefore, we investigated the effects of DEX on CD163 expression in porcine IPKM. Treatment with DEX markedly enhanced CD163 expression in the IPKM. In addition, we found that SB203580, a selective inhibitor of p38 mitogen-activated protein kinase (MAPK), blocked the effects of DEX, suggesting that the p38 MAPK signaling pathway is involved in the regulation of the DEX-induced enhancement of CD163 expression. Since CD163 is considered to be a putative receptor for the porcine reproductive and respiratory syndrome virus (PRRSV), the effects of DEX on the infection of IPKM by PRRSV were evaluated. Although the IPKM were susceptible to infection by the Fostera PRRSV vaccine strain, DEX treatment did not affect the propagation of the virus in the IPKM. This suggests that the DEX-induced enhancement of CD163 expression alone is not sufficient to facilitate the infection of IPKM by PRRSV.

在我们之前的研究中，我们建立了一个独特的猪巨噬细胞系，永生化猪肾源巨噬细胞 (IPKM)。本研究的目的是进一步阐明 IPKM 的特征。CD163 是血红蛋白-结合珠蛋白复合物的清道夫受体，用作抗炎 M2 巨噬细胞的表型标志物。CD163 的表达被地塞米松 (DEX) 增强，地塞米松是一种有效的甾体抗炎药，在体外人类和啮齿动物巨噬细胞中。因此，我们研究了 DEX 对猪 IPKM 中 CD163 表达的影响。用 DEX 处理显着增强了 IPKM 中的 CD163 表达。此外，我们发现 SB203580，一种 p38 丝裂原活化蛋白激酶 (MAPK) 的选择性抑制剂，阻断了 DEX 的作用，表明 p38 MAPK 信号通路参与了 DEX 诱导的 CD163 表达增强的调节。由于 CD163 被认为是猪繁殖与呼吸综合征病毒 (PRRSV) 的推定受体，因此评估了 DEX 对 PRRSV 感染 IPKM 的影响。尽管 IPKM 易受 Fostera PRRSV 疫苗株感染，但 DEX 处理不影响病毒在 IPKM 中的传播。这表明 DEX 诱导的 CD163 表达单独增强不足以促进 IPKM 被 PRRSV 感染。评价了DEX对PRRSV感染IPKM的作用。尽管 IPKM 易受 Fostera PRRSV 疫苗株感染，但 DEX 处理不影响病毒在 IPKM 中的传播。这表明 DEX 诱导的 CD163 表达单独增强不足以促进 IPKM 被 PRRSV 感染。评价了DEX对PRRSV感染IPKM的作用。尽管 IPKM 易受 Fostera PRRSV 疫苗株感染，但 DEX 处理不影响病毒在 IPKM 中的传播。这表明 DEX 诱导的 CD163 表达单独增强不足以促进 IPKM 被 PRRSV 感染。