Park Ji-Yun, Shin Dong-Jun, Lee Soo-Hyeon, Lee Je-Jung, Suh Guk-Hyun, Cho Duck, Kim Sang-Ki
Department of Companion & Laboratory Animal Science, Kongju National University, Yesan, Chungnam 340-702, Republic of Korea.
Department of Companion & Laboratory Animal Science, Kongju National University, Yesan, Chungnam 340-702, Republic of Korea; Research Center for Cancer Immunotherapy, Chonnam National University Hwasun Hospital, Jeollanamdo 519-809, Republic of Korea.
Vet Microbiol. 2015 Apr 17;176(3-4):239-49. doi: 10.1016/j.vetmic.2015.01.021. Epub 2015 Feb 3.
Natural killer (NK) cells play critical roles in induction of antiviral effects against various viruses of humans and animals. However, few data on NK cell activities during canine distemper virus (CDV) infections are available. Recently, we established a culture system allowing activation and expansion of canine non-B, non-T, large granular NK lymphocytes from PBMCs of normal dogs. In the present study, we explored the ability of such expanded NK cells to inhibit CDV infection in vitro. Cultured CD3-CD5-CD21- NK cells produced large amounts of IFN-γ, exhibited highly upregulated expression of mRNAs encoding NK-cell-associated receptors, and demonstrated strong natural killing activity against canine tumor cells. Although the expanded NK cells were dose-dependently cytotoxic to both normal and CDV-infected Vero cells, CDV infection rendered Vero cells more susceptible to NK cells. Pretreatment with anti-CDV serum from hyperimmunized dogs enhanced the antibody-dependent cellular cytotoxicity (ADCC) of NK cells against CDV-infected Vero cells. The culture supernatants of NK cells, added before or after infection, dose-dependently inhibited both CDV replication and development of CDV-induced cytopathic effects (CPEs) in Vero cells. Anti-IFN-γ antibody neutralized the inhibitory effects of NK cell culture supernatants on CDV replication and CPE induction in Vero cells. Such results emphasize the potential significance of NK cells in controlling CDV infection, and indicate that NK cells may play roles both during CDV infection and in combating such infections, under certain conditions.
自然杀伤（NK）细胞在诱导针对人类和动物各种病毒的抗病毒效应中发挥关键作用。然而，关于犬瘟热病毒（CDV）感染期间NK细胞活性的数据却很少。最近，我们建立了一种培养系统，可从正常犬的外周血单核细胞（PBMC）中激活并扩增犬非B、非T大颗粒NK淋巴细胞。在本研究中，我们探讨了这种扩增后的NK细胞在体外抑制CDV感染的能力。培养的CD3-CD5-CD21-NK细胞产生大量干扰素-γ，编码NK细胞相关受体的mRNA表达高度上调，并对犬肿瘤细胞表现出强大的自然杀伤活性。尽管扩增后的NK细胞对正常和CDV感染的Vero细胞均具有剂量依赖性细胞毒性，但CDV感染使Vero细胞对NK细胞更敏感。用高免疫犬的抗CDV血清预处理可增强NK细胞对CDV感染的Vero细胞的抗体依赖性细胞毒性（ADCC）。在感染前或感染后添加NK细胞的培养上清液，可剂量依赖性地抑制Vero细胞中CDV的复制以及CDV诱导的细胞病变效应（CPE）的发展。抗干扰素-γ抗体可中和NK细胞培养上清液对Vero细胞中CDV复制和CPE诱导的抑制作用。这些结果强调了NK细胞在控制CDV感染中的潜在重要性，并表明NK细胞在CDV感染期间以及在某些条件下对抗此类感染过程中可能发挥作用。
