Bertol Jéssica Wildgrube, Fregolente Maria Clara Duarte, Caruzo Thabata Alessandra Ramos, Silva Márcio José da, Munford Veridiana, Sáfadi Marco Aurélio Palazzi, Rácz Maria Lucia, Gatti Maria Silvia Viccari
Departamento de Genética, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, SP, Brasil.
Centro de Biologia Molecular e Engenharia Genética, Universidade Estadual de Campinas, Campinas, SP, Brasil.
Mem Inst Oswaldo Cruz. 2015 Sep;110(6):786-92. doi: 10.1590/0074-02760150199.
Group A human rotaviruses (HuRVA) are causative agents of acute gastroenteritis. Six viral structural proteins (VPs) and six nonstructural proteins (NSPs) are produced in RV-infected cells. NSP4 is a diarrhoea-inducing viral enterotoxin and NSP4 gene analysis revealed at least 15 (E1-E15) genotypes. This study analysed the NSP4 genetic diversity of HuRVA G2P[4] strains collected in the state of São Paulo (SP) from 1994 and 2006-2010 using reverse transcription-polymerase chain reaction, sequencing and phylogenetic analysis. Forty (97.6%) G2P[4] strains displayed genotype E2; one strain (2.4%) displayed genotype E1. These results are consistent with the proposed linkage between VP4/VP7 (G2P[4]) and the NSP4 (E2) genotype of HuRVA. NSP4 phylogenetic analysis showed distinct clusters, with grouping of most strains by their genotype and collection year, and most strains from SP were clustered together with strains from other Brazilian states. A deduced amino acid sequence alignment for E2 showed many variations in the C-terminal region, including the VP4-binding domain. Considering the ability of NSP4 to generate host immunity, monitoring NSP4 variations, along with those in the VP4 or VP7 protein, is important for evaluating the circulation and pathogenesis of RV. Finally, the presence of one G2P[4]E1 strain reinforces the idea that new genotype combinations emerge through reassortment and independent segregation.
A组人轮状病毒（HuRVA）是急性胃肠炎的病原体。轮状病毒感染的细胞会产生六种病毒结构蛋白（VPs）和六种非结构蛋白（NSPs）。NSP4是一种可导致腹泻的病毒肠毒素，NSP4基因分析揭示了至少15种（E1 - E15）基因型。本研究使用逆转录 - 聚合酶链反应、测序和系统发育分析，对1994年以及2006 - 2010年在圣保罗州（SP）收集的HuRVA G2P[4]毒株的NSP4基因多样性进行了分析。40株（97.6%）G2P[4]毒株表现为E2基因型；1株（2.4%）表现为E1基因型。这些结果与所提出的HuRVA的VP4/VP7（G2P[4]）与NSP4（E2）基因型之间的联系一致。NSP4系统发育分析显示出不同的聚类，大多数毒株按其基因型和收集年份分组，并且来自圣保罗州的大多数毒株与来自巴西其他州的毒株聚集在一起。E2的推导氨基酸序列比对显示C末端区域存在许多变异，包括VP4结合结构域。考虑到NSP4产生宿主免疫的能力，监测NSP4的变异以及VP4或VP7蛋白的变异，对于评估轮状病毒的传播和发病机制很重要。最后，一株G2P[4]E1毒株的存在强化了这样一种观点，即新的基因型组合是通过重配和独立分离产生的。
