Chen Yu, Gong Junhao, Zhan Tiansong, Wang Mingzhan, Hu Shunlin, Liu Xiufan
Animal Infectious Disease Laboratory, College of Veterinary Medicine, Yangzhou University, Yangzhou 225012, China.
Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonosis, Yangzhou University, Yangzhou 225012, China.
Vet Sci. 2024 Nov 25;11(12):592. doi: 10.3390/vetsci11120592.
Pigeon Newcastle disease (ND) is the most common viral infectious disease in the pigeon industry, caused by pigeon paramyxovirus type 1 (PPMV-1), a variant of chicken-origin Newcastle disease virus (NDV). Previous studies have identified significant amino acid differences between PPMV-1 and chicken-origin NDV at positions 347 and 349 in the hemagglutinin-neuraminidase (HN) protein, with PPMV-1 predominantly exhibiting glycine (G) at position 347 and glutamic acid (E) at position 349, while most chicken-origin NDVs show E at position 347 and aspartic acid (D) at position 349. However, the impact of these amino acid substitutions remains unclear. In this study, we generated a recombinant virus, NT-10-G347E/E349D, by introducing the G347E and E349D dual mutations into a PPMV-1 strain NT-10 using reverse genetics. The biological characteristics of NT-10 and NT-10-G347E/E349D were compared both in vitro and in vivo. In vitro, the G347E and E349D dual mutations reduce NT-10's replication and neuraminidase activity in pigeon embryo fibroblast (PEF) cells while enhancing both in chicken embryo fibroblast (CEF) cells. Additionally, these mutations decrease NT-10's binding affinity to the α-2,6 sialic acid receptor while significantly increasing its affinity for the α-2,3 receptor. In vivo, NT-10-G347E/E349D exhibited reduced pathogenicity in pigeons but increased pathogenicity in chickens compared to the parental NT-10 strain. The mutations also reduced the pigeon-to-pigeon transmission of NT-10 but enhanced its transmission from pigeons to chickens. Notably, significant antigenic differences were observed between NT-10 and NT-10-G347E/E349D, as an inactivated vaccine based on NT-10 provided full protection against NT-10 challenge in immunized pigeons but only 67% mortality protection against NT-10-G347E/E349D. Overall, these findings underscore the critical role of amino acids at positions 347 and 349 in PPMV-1 infection, pathogenicity, and transmission, providing a theoretical foundation for the scientific prevention and control of PPMV-1.
鸽新城疫（ND）是养鸽业中最常见的病毒性传染病，由1型鸽副粘病毒（PPMV-1）引起，它是鸡源新城疫病毒（NDV）的一个变种。先前的研究已经确定，PPMV-1和鸡源NDV在血凝素神经氨酸酶（HN）蛋白的347位和349位存在显著的氨基酸差异，PPMV-1在347位主要表现为甘氨酸（G），在349位为谷氨酸（E），而大多数鸡源NDV在347位为E，在349位为天冬氨酸（D）。然而，这些氨基酸替换的影响仍不清楚。在本研究中，我们通过反向遗传学将G347E和E349D双突变引入PPMV-1毒株NT-10，构建了重组病毒NT-10-G347E/E349D。对NT-10和NT-10-G347E/E349D的生物学特性进行了体内外比较。在体外，G347E和E349D双突变降低了NT-10在鸽胚成纤维细胞（PEF）中的复制和神经氨酸酶活性，而在鸡胚成纤维细胞（CEF）中则增强了这两种活性。此外，这些突变降低了NT-10与α-2,6唾液酸受体的结合亲和力，同时显著增加了其与α-2,3受体的亲和力。在体内，与亲本NT-10毒株相比，NT-10-G347E/E349D在鸽中的致病性降低，但在鸡中的致病性增加。这些突变还减少了NT-10在鸽与鸽之间的传播，但增强了其从鸽到鸡的传播。值得注意的是，NT-10和NT-10-G347E/E349D之间观察到显著的抗原差异，基于NT-10的灭活疫苗在免疫鸽中能提供完全保护以抵抗NT-10攻击，但对NT-10-G347E/E349D的致死保护率仅为67%。总体而言，这些发现强调了PPMV-1中347位和349位氨基酸在感染、致病性和传播中的关键作用，为PPMV-1的科学防控提供了理论基础。
