Lappalainen Suvi, Tamminen Kirsi, Vesikari Timo, Blazevic Vesna
Vaccine Research Center; University of Tampere Medical School; Tampere, Finland.
Hum Vaccin Immunother. 2013 Sep;9(9):1991-2001. doi: 10.4161/hv.25249. Epub 2013 Jun 18.
Rotavirus (RV) is the most important cause of severe gastroenteritis in children worldwide. Current live RV vaccines are efficacious but show lower efficacy in developing countries, as well as a low risk of intussusception. This has led to the development of parenteral non-live candidate vaccines against RV. RV capsid VP6 protein is highly conserved and the most abundant RV protein forming highly immunogenic oligomeric structures with multivalent antigen expression. Both recombinant VP6 (rVP6) or double-layered (dl) 2/6-virus-like particles (VLPs), might be considered as the simplest RV subunit vaccine candidates. Human rVP6 protein and dl2/6-VLPs were produced in Sf9 insect cells by baculovirus expression system. Formation of rVP6 tubules and VLPs were confirmed by electron microscopy. BALB/c mice were immunized intramuscularly, and immune responses were analyzed. Both rVP6 and dl2/6-VLPs induced a balanced Th1-type and Th2-type response and high levels of serum IgG antibodies with cross-reactivity against different RV strains (Wa, SC2, BrB, 69M, L26, WC3, and RRV). In addition, mucosal VP6-specific IgG and IgA antibodies were detected in feces and vaginal washes (VW) of immunized animals. Importantly, VWs of immunized mice inhibited RV Wa and RRV infection in vitro. Immunization with either protein preparation induced a similar level of VP6-specific, interferon-γ secreting CD4(+) T cells in response to different RVs or the 18-mer peptide (AA 242-259), a VP6-specific CD4(+) T cell epitope. RV rVP6 and dl2/6-VLPs induced equally strong humoral and cellular responses against RV in mice and therefore, may be considered as non-live vaccine candidates against RV.
轮状病毒（RV）是全球儿童严重胃肠炎的最重要病因。目前的活RV疫苗有效，但在发展中国家显示出较低的效力，并且肠套叠风险较低。这导致了针对RV的非活肠外候选疫苗的开发。RV衣壳VP6蛋白高度保守，是形成具有多价抗原表达的高免疫原性寡聚结构的最丰富的RV蛋白。重组VP6（rVP6）或双层（dl）2/6病毒样颗粒（VLP）都可被视为最简单的RV亚单位疫苗候选物。人rVP6蛋白和dl2/6-VLP通过杆状病毒表达系统在Sf9昆虫细胞中产生。通过电子显微镜确认了rVP6小管和VLP的形成。对BALB/c小鼠进行肌肉注射免疫，并分析免疫反应。rVP6和dl2/6-VLP均诱导了平衡的Th1型和Th2型反应以及高水平的血清IgG抗体，这些抗体对不同的RV毒株（Wa、SC2、BrB、69M、L26、WC3和RRV）具有交叉反应性。此外，在免疫动物的粪便和阴道灌洗液（VW）中检测到粘膜VP6特异性IgG和IgA抗体。重要的是，免疫小鼠的VW在体外抑制了RV Wa和RRV感染。用任何一种蛋白质制剂免疫均诱导了相似水平的VP6特异性、分泌干扰素-γ的CD4(+) T细胞，以响应不同的RV或18聚体肽（氨基酸242-259），即VP6特异性CD4(+) T细胞表位。RV rVP6和dl2/6-VLP在小鼠中诱导了同样强烈的针对RV的体液和细胞反应，因此，可被视为针对RV的非活疫苗候选物。
