Ghalyanchilangeroudi Arash, Hosseini Hossein, Nazarpak Hadi Haghbin, Molouki Aidin, Dezfoulian Omid, Morshed Rima
Department of Microbiology and Immunology, University of Tehran, Faculty of Veterinary Medicine, Tehran, Iran 1419963111.
Department of Clinical Sciences, Karaj Branch, Islamic Azad University, Karaj, Iran 3149968111,
Avian Dis. 2022 Oct;66(3):1-5. doi: 10.1637/aviandiseases-D-22-00018. Epub 2022 Sep 9.
Marek's disease (MD) is a highly contagious, lymphoproliferative poultry disease caused by the oncogenic herpesvirus, serotype 1 Marek's disease virus (MDV-1), or 2 (GaHV-2). MDV strains have shown a continued evolution of virulence leading to immune failure, and MD cases continue to occur or surge. , the major MDV-1 oncoprotein, induces T-cell neoplastic transformation through several mechanisms including inhibition of apoptosis, cell cycle regulation, and serum-anchorage independent growth. There is no current information on the MDV serotypes and pathotypes circulating in vaccinated commercial farms in Iran, where the birds are vaccinated at the hatchery with GaHV-2 and 1 (MeHV-1) vaccines. This study reports the molecular characterization of a GaHV-2 strain detected in 19 flocks of Iranian layer farms exhibiting MDV-1-like clinical signs and visceral lymphomas. Based on sequencing and phylogenetic analysis of the gene, the Iranian GaHV-2 isolates could be divided into two separate clades regarding molecular features. The clade containing strains was closely related to Italian, Indian, and Hungarian virulent isolates, and the clade was related to American very virulent plus (vv+) isolates. For the first time, the MDV-1 virus was characterized by an outbreak in poultry flocks in Iran. Although MDV-1 strains obtained in Iran's present outbreak are presumably related to virulent (v) and vv+ pathotypes based on nucleotide, amino acid, and phylogenetic analysis of the viruses, they are not confirmed so far. Thus, it is highly recommended to perform further analyses to demonstrate the pathotype characteristics .
马立克氏病（MD）是一种由致癌性疱疹病毒引起的高度传染性、淋巴细胞增生性家禽疾病，1型马立克氏病病毒（MDV-1）或2型（GaHV-2）。MDV毒株的毒力不断进化，导致免疫失败，MD病例持续发生或激增。主要的MDV-1癌蛋白通过多种机制诱导T细胞肿瘤转化，包括抑制细胞凋亡、细胞周期调控和血清非锚定依赖性生长。目前尚无关于伊朗商业化养殖场中循环的MDV血清型和致病型的信息，在这些养殖场中，雏鸡在孵化场接种了GaHV-2和1型（MeHV-1）疫苗。本研究报告了在19个表现出MDV-1样临床症状和内脏淋巴瘤的伊朗蛋鸡养殖场鸡群中检测到的一株GaHV-2毒株的分子特征。基于基因的测序和系统发育分析，伊朗GaHV-2分离株在分子特征上可分为两个独立的进化枝。包含毒株的进化枝与意大利、印度和匈牙利的强毒株密切相关，而该进化枝与美国的超强毒Plus（vv+）毒株相关。首次对伊朗家禽群中爆发的MDV-1病毒进行了特征描述。尽管根据病毒的核苷酸、氨基酸和系统发育分析，在伊朗当前疫情中获得的MDV-1毒株可能与强毒（v）和vv+致病型有关，但目前尚未得到证实。因此，强烈建议进行进一步分析以证明致病型特征。
