Department of Virology, Parasitology and Immunology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820, Merelbeke, Belgium.
Vet Res. 2013 Aug 21;44(1):71. doi: 10.1186/1297-9716-44-71.
Feline infectious peritonitis (FIP) is the most feared infectious cause of death in cats, induced by feline infectious peritonitis virus (FIPV). This coronavirus is a virulent mutant of the harmless, ubiquitous feline enteric coronavirus (FECV). To date, feline coronavirus (FCoV) research has been hampered by the lack of susceptible cell lines for the propagation of serotype I FCoVs. In this study, long-term feline intestinal epithelial cell cultures were established from primary ileocytes and colonocytes by simian virus 40 (SV40) T-antigen- and human Telomerase Reverse Transcriptase (hTERT)-induced immortalization. Subsequently, these cultures were evaluated for their usability in FCoV research. Firstly, the replication capacity of the serotype II strains WSU 79-1683 and WSU 79-1146 was studied in the continuous cultures as was done for the primary cultures. In accordance with the results obtained in primary cultures, FCoV WSU 79-1683 still replicated significantly more efficient compared to FCoV WSU 79-1146 in both continuous cultures. In addition, the cultures were inoculated with faecal suspensions from healthy cats and with faecal or tissue suspensions from FIP cats. The cultures were susceptible to infection with different serotype I enteric strains and two of these strains were further propagated. No infection was seen in cultures inoculated with FIPV tissue homogenates. In conclusion, a new reliable model for FCoV investigation and growth of enteric field strains was established. In contrast to FIPV strains, FECVs showed a clear tropism for intestinal epithelial cells, giving an explanation for the observation that FECV is the main pathotype circulating among cats.
猫传染性腹膜炎（Feline infectious peritonitis，FIP）是猫最可怕的传染性致死病因，由猫传染性腹膜炎病毒（Feline infectious peritonitis virus，FIPV）引起。这种冠状病毒是一种无害的、普遍存在的猫肠道冠状病毒（Feline enteric coronavirus，FECV）的烈性突变体。迄今为止，由于缺乏适合传播 I 型 FCoV 的易感细胞系，猫冠状病毒（Feline coronavirus，FCoV）的研究受到了阻碍。在这项研究中，通过猴病毒 40（Simian virus 40，SV40）T 抗原和人端粒酶逆转录酶（human Telomerase Reverse Transcriptase，hTERT）诱导的永生化，从原代回肠和结肠细胞中建立了长期的猫肠道上皮细胞培养物。随后，评估了这些培养物在 FCoV 研究中的可用性。首先，研究了 II 型菌株 WSU 79-1683 和 WSU 79-1146 在连续培养中的复制能力，这与原代培养中的情况相同。与原代培养中获得的结果一致，FCoV WSU 79-1683 在两种连续培养中的复制效率仍明显高于 FCoV WSU 79-1146。此外，还将粪便悬液接种到健康猫和 FIP 猫的粪便或组织悬液中。这些培养物易受不同 I 型肠内株的感染，其中两种株进一步繁殖。接种 FIPV 组织匀浆的培养物未观察到感染。总之，建立了一种新的可靠的 FCoV 研究和肠内田间株生长模型。与 FIPV 株不同，FECV 对肠道上皮细胞具有明显的趋向性，这解释了为什么 FECV 是猫中主要流行的病原体。
