猪圆环病毒4型(PCV4),最近发现的一种圆环病毒,在中国许多省份都很普遍,以及在韩国,泰国,和欧洲。从感染性克隆中拯救的PCV4病毒显示出致病性,表明PCV4的经济影响。然而,关于PCV4的免疫原性和表位仍缺乏了解。本研究通过用PCV4病毒样颗粒(VLP)免疫小鼠产生单克隆抗体(MAb)1D8。随后,通过截短的蛋白质表达和丙氨酸扫描诱变分析鉴定MAb1D8识别的表位。结果显示,位于PCV4Cap蛋白C末端的225PKQG228是与MAb结合的最小基序。同源性建模分析和免疫电子显微镜显示表位延伸超过PCV4VLP的外表面。此外,该表位在PCV4菌株中高度保守,不与其他PCV反应。一起,MAb1D8识别的表位显示出检测PCV4的潜力。这些发现显著有助于设计用于PCV4检测和控制策略的抗原。
目的:猪圆环病毒4型(PCV4)是一种新型圆环病毒。虽然PCV4已经在几个国家被识别出来,包括中国,韩国,泰国,西班牙,没有疫苗可用。鉴于PCV4对猪的潜在致病作用,PCV4可能威胁全球养猪业,强调进一步调查的紧迫性。因此,PCV4的表位仍有待确定。我们对保守表位的发现显着促进了疫苗开发和病原体检测。
Porcine circovirus type 4 (PCV4), a recently identified circovirus, is prevalent in numerous provinces in China, as well as in South Korea, Thailand, and Europe. PCV4 virus rescued from an infectious clone showed pathogenicity, suggesting the economic impact of PCV4. However, there remains a lack of understanding regarding the immunogenicity and epitopes of PCV4. This study generated a monoclonal antibody (MAb) 1D8 by immunizing mice with PCV4 virus-like particles (VLPs). Subsequently, the epitope recognized by the MAb 1D8 was identified by truncated protein expression and alanine scanning mutagenesis analysis. Results showed that the 225PKQG228 located at the C-terminus of the PCV4 Cap protein is the minimal motif binding to the MAb. Homology modeling analysis and immunoelectron microscopy revealed that the epitope extends beyond the outer surface of the PCV4 VLP. Moreover, the epitope is highly conserved among PCV4 strains and does not react with other PCVs. Together, the MAb 1D8 recognized epitope shows potential for detecting PCV4. These findings significantly contribute to the design of antigens for PCV4 detection and control strategies.
OBJECTIVE: Porcine circovirus type 4 (PCV4) is a novel circovirus. Although PCV4 has been identified in several countries, including China, Korea, Thailand, and Spain, no vaccine is available. Given the potential pathogenic effects of PCV4 on pigs, PCV4 could threaten the global pig farming industry, highlighting the urgency for further investigation. Thus, epitopes of PCV4 remain to be determined. Our finding of a conserved epitope significantly advances vaccine development and pathogen detection.