Transmissible gastroenteritis virus (TGEV) causes enteric infection in piglets, characterized by vomiting, severe diarrhea and dehydration, and the mortality in suckling piglets is often high up to 100%. Vaccination is an effective measure to control the disease caused by TGEV. In this study, cell-cultured TGEV HN-2012 strain was inactivated by formaldehyde (FA), β-propiolactone (BPL) or binaryethylenimine (BEI), respectively. Then the inactivated TGEV vaccine was prepared with freund's adjuvant, and the immunization effects were evaluated in mice. The TGEV-specific IgG level was detected by ELISA. The positive rates of CD4+, CD8+, CD4+IFN-γ+, CD4+IL-4+ T lymphocytes were detected by flow cytometry assay. Lymphocyte proliferation assay and gross pathology and histopathology examination were also performed to assess the three different inactivating reagents in formulating TGEV vaccine. The results showed that the TGEV-specific IgG level in FA group (n = 17) was earlier and stronger, while the BEI group produced much longer-term IgG level. The lymphocyte proliferation test demonstrated that the BEI group had a stronger ability to induce spleen lymphocyte proliferation. The positive rates of CD4+ and CD8+ T lymphocyte subsets of peripheral blood lymphocyte in BEI group was higher than that in FA group and BPL groups by flow cytometry assay. The positive rate of CD4+IFN-γ+ T lymphocyte subset was the highest in the BPL group, and the positive rate of CD4+IL-4+ T lymphocyte subset was the highest in the FA group. There were no obvious pathological changes in the vaccinated mice and the control group after the macroscopic and histopathological examination. These results indicated that all the three experimental groups could induce cellular and humoral immunity, and the FA group had the best humoral immunity effect, while the BEI group showed its excellent cellular immunity effect.

中文翻译：

---

不同灭活试剂配制传染性胃肠炎病毒疫苗的评价

传染性胃肠炎病毒（TGEV）引起仔猪肠道感染，表现为呕吐、严重腹泻和脱水，哺乳仔猪的死亡率往往高达100%。接种疫苗是控制TGEV引起的疾病的有效措施。在这项研究中，细胞培养的 TGEV HN-2012 菌株分别被甲醛 (FA)、β-丙内酯 (BPL) 或二亚乙基亚胺 (BEI) 灭活。然后用弗氏佐剂制备灭活的TGEV疫苗，并在小鼠体内评价免疫效果。通过ELISA检测TGEV特异性IgG水平。流式细胞术检测CD4+、CD8+、CD4+IFN-γ+、CD4+IL-4+T淋巴细胞阳性率。还进行了淋巴细胞增殖试验和大体病理学和组织病理学检查，以评估配制 TGEV 疫苗中的三种不同灭活试剂。结果表明，FA组（n=17）TGEV特异性IgG水平更早且更强，而BEI组产生更长期的IgG水平。淋巴细胞增殖试验表明，BEI组具有更强的诱导脾淋巴细胞增殖能力。流式细胞术检测BEI组外周血淋巴细胞CD4+和CD8+T淋巴细胞亚群阳性率高于FA组和BPL组。BPL组CD4+IFN-γ+T淋巴细胞亚群阳性率最高，FA组CD4+IL-4+T淋巴细胞亚群阳性率最高。经肉眼观察和组织病理学检查，接种疫苗的小鼠和对照组均未见明显病理改变。以上结果表明，3个实验组均能诱导细胞免疫和体液免疫，其中FA组的体液免疫效果最好，而BEI组显示出优异的细胞免疫效果。