Virology, Genetics and Molecular Biology Laboratory, Faculty of Higher Education, Cuautitlan, Veterinary Medicine, Campus 4, National Autonomous University of Mexico, Km. 2.5 Carretera Cuautitlán-Teoloyucan San Sebastián Xhala, Cuautitlan Izcalli, Estado de México, C.P. 54714, Mexico.
Laboratory of Immunovirology, Medical Research in Immunology Unit, Pediatric Hospital, National Medical Center XXI Century, Mexican Institute of Social Security, Mexico.
Virus Res. 2020 Apr 15;280:197900. doi: 10.1016/j.virusres.2020.197900. Epub 2020 Feb 15.
The env gene in Small Ruminant Lentiviruses (SRLV) encodes the surface glycoprotein (SU) that divides into conserved (C1-C4) and variable regions (V1-V5). SRLV region V4 has been found to be homologous to the V3 region of human lentivirus (HIV). HIV V3 is responsible for tropism and the development of nervous clinical patterns when there is a tendency to conserve amino acids in specific "signature pattern" positions. The goal of this study was to identify signature patterns in the V4 region of the SU, which is encoded by the SRLV env gene. Secondarily, to understand how these signature patterns are associated with different clinical status in naturally infected sheep and goats. Starting with 244 samples from seropositive animals from nine Mexican states, we amplified the V4 region using nested PCR and obtained 49 SRLV sequences from peripheral blood leukocytes. Based on phylogenetic analysis results, we identified three groups: asymptomatic genotypes A (Ssx GA) and B (Ssx GB), as well as animals with arthritic presentation, genotype B (A GB). Similarity levels between group sequences ranged from 67.9%-86.7%, with a genetic diversity ranging from 12.7%-29.5% and a dN / dS ratio that indicated negative selection. Analyses using Vespa and Entropy programs identified four residues at positions 54, 78, 79 and 82 in SU region V4 as possible signature patterns, although with variable statistical significance. However, position 54 residues "N" (p = 0.017), "T" (p = 0.001) and "G" (p = 0.024) in groups A GB, Ssx GA and Ssx GB respectively, best characterized the signature patterns. The results obtained identified a signature pattern related to different genotypes and clinical status by SRLV in sheep and goats.
小反刍兽瘟病毒（SRLV）的 env 基因编码表面糖蛋白（SU），分为保守区（C1-C4）和可变区（V1-V5）。已发现 SRLV 区 V4 与人类慢病毒（HIV）的 V3 区同源。HIV V3 负责趋化性，并在特定“特征模式”位置的氨基酸倾向于保守时导致神经临床模式的发展。本研究的目的是鉴定 SU 编码的 SRLV env 基因 V4 区的特征模式。其次，了解这些特征模式如何与自然感染绵羊和山羊的不同临床状况相关。从来自墨西哥九个州的血清阳性动物的 244 个样本开始，我们使用巢式 PCR 扩增 V4 区，并从外周血白细胞中获得 49 个 SRLV 序列。基于系统发育分析结果，我们鉴定了三个组：无症状基因型 A（SsxGA）和 B（SsxB），以及表现出关节炎的动物，基因型 B（A GB）。组序列之间的相似性水平为 67.9%-86.7%，遗传多样性为 12.7%-29.5%，dN/dS 比值表明存在负选择。使用 Vespa 和 Entropy 程序进行的分析确定了 SU 区 V4 中四个位置 54、78、79 和 82 的残基可能是特征模式，尽管具有可变的统计显着性。然而，位置 54 残基“N”（p=0.017）、“T”（p=0.001）和“G”（p=0.024）在 A GB、SsxGA 和 SsxGB 组中分别最好地描述了特征模式。所得结果确定了与绵羊和山羊中不同基因型和临床状况相关的特征模式。
