分析谱系和检测A组轮状病毒(RVA)变体的免疫原性基序中的抗原变异是至关重要的,因为它可以影响疫苗效力。这项研究调查了人类RVA分离株的VP4和VP7蛋白的循环谱系及其在≤24个月大的症状,2020年12月至2022年3月期间,在德黑兰的Mofid儿童医院入院48小时内出现传染性腹泻的轮状病毒阳性儿童,伊朗。通过ELISA进行抗原检测,RNA提取,G/P基因型的半巢式多重PCR,然后使用MEGA中的多序列比对和GeneiousPrime的系统发育分析进行测序和生物信息学分析。使用UCSF嵌合体分子建模系统评估了VP7和VP4氨基酸与RotaTeq和Rotarix疫苗株对于细胞毒性T细胞和抗原表位的相似性。总的来说,27.3%的样本为RVA阳性,显示不可型(2.5%),单身(76.9%),和混合(20.5%)的基因型特征。菌株聚集在G1/II,G2/IV,G3/I,G4/I,G9/III,P(Kachooei等人,2023年)[8]/III,P(豪利等人,2020)[4]/V,和P(Wahyuni等人,2021)[6]/I谱系。VP7抗原表位的比较分析表明G1/II株完全保守,而G2/IV,G3/I,G4/I,G6、G9/III菌株含有2、3-5、2、4和9个氨基酸取代,分别。P(Kachooei等人,2023)[8]/III基因型相差3个氨基酸,而P(Wahyuni等人,2021年)[6]/I基因型取代最多。CTL表位在G3/I菌株中完全保守,但是与疫苗株相比,其他基因型的差异为1-4个氨基酸。鉴于循环RVA基因型的多样性和观察到的中和和CTL表位突变,一些菌株的免疫逃逸可能在伊朗。这一发现强调了在实施疫苗接种计划之前评估轮状病毒疫苗对当地基因型和相关谱系的影响的重要性。
Analyzing the lineages and detecting antigenic variation in immunogenic motifs of Group A Rotavirus (RVA) variants is crucial because it can impact vaccine efficacy. This study investigated the circulating lineages of VP4 and VP7 proteins of human RVA isolates and their phylogeny in ≤24-month-old symptomatic, rotavirus-positive children with transudative diarrhea within 48 h of admission to Mofid Children\'s Hospital between December 2020 and March 2022 in Tehran, Iran. Antigen detection was performed by ELISA, RNA extraction, and semi-nested multiplex PCR for G/P genotypes, followed by sequencing and bioinformatic analysis using multiple sequence alignments in MEGA and phylogenetic analysis by Geneious Prime. The similarity of VP7 and VP4 amino acids with the RotaTeq and Rotarix vaccine strains for cytotoxic T cell and antigenic epitopes was evaluated using the UCSF Chimera Molecular Modeling System. Overall, 27.3 % of the samples were RVA positive, showing untypeable (2.5 %), single (76.9 %), and mixed (20.5 %) genotypic characteristics. The strains clustered in the G1/II, G2/IV, G3/I, G4/I, G9/III, P (Kachooei et al., 2023) [8]/III, P (Howley et al., 2020) [4]/V, and P (Wahyuni et al., 2021) [6]/I lineages. Comparative analysis of VP7 antigenic epitopes showed that the G1/II strains were completely conserved, while the G2/IV, G3/I, G4/I, G6, G9/III strains contained 2, 3-5, 2, 4 and 9 amino acid substitutions, respectively. The P (Kachooei et al., 2023) [8]/III genotypes differed by 3 amino acids, while the P (Wahyuni et al., 2021) [6]/I genotype had the most substitutions. CTL epitopes were completely conserved in G3/I strains, but other genotypes differed by 1-4 amino acids compared to the vaccine strains. Given the diversity of circulating RVA genotypes and the observed mutations in neutralizing and CTL epitopes, immune escape by some of the strains is likely in Iran. This finding underscores the importance of evaluating the effect of rotavirus vaccines on local genotypes and related lineages before implementing a vaccination program.