Graduate Institute of Microbiology and Public Health, National Chung Hsing University, Taichung 40227, Taiwan.
Department of Veterinary Medicine, National Chung Hsing University, Taichung 40227, Taiwan.
Avian Dis. 2023 Jun;67(2):153-159. doi: 10.1637/aviandiseases-D-22-00084.
is an important respiratory pathogen of domestic chickens. has been subtyped into three serogroups and nine serovars according to the Page and revised Kume schemes. The major hemagglutinin antigen of is HMTp210, which is a large protein of about 2000 amino acids (aa), including a 70-aa signal peptide at its N-terminal end. However, the regions important for the hemagglutination (HA) activity and serotypes of HMTp210 remain unclear. In this study we constructed a series of strains expressing HMTp210 in-frame deletion mutants and determined their HA titers to identify the regions important for the HA activity and serotypes of HMTp210. Two distinct types of HA activities were found in HMTp210. The type 1 HA activity resided in the region spanning the full-length HA (aa 71-2084), whereas the type 2 resided in the region spanning aa 1003-2084. The putative ligand binding of the type 1 HA activity was located at aa 176-360, which had a structure similar to YadA of . The putative ligand binding site of the type 2 HA activity was located at aa 1003-1125, which had a structure similar to UspA1 from . The type 1 HA activity appeared to be Page serogroup specific, whereas type 2 appeared to be Kume serovar specific. Finally, sequence analyses of the regions spanning aa 1-400 and aa 1100-1600 of HMTp210 could be useful for the molecular serotyping (the Page and revised Kume schemes) of isolates.
是一种重要的家禽呼吸道病原体。根据 Page 和修订后的 Kume 方案，已将其分为三个血清群和九个血清型。的主要血凝素抗原是 HMTp210，它是一种大约 2000 个氨基酸（aa）的大蛋白，其 N 端有一个 70-aa 的信号肽。然而，对于 HMTp210 的血凝（HA）活性和血清型重要的区域仍然不清楚。在这项研究中，我们构建了一系列表达 HMTp210 框内缺失突变体的菌株，并测定了它们的 HA 滴度，以确定 HMTp210 的 HA 活性和血清型重要的区域。在 HMTp210 中发现了两种不同类型的 HA 活性。1 型 HA 活性位于全长 HA（aa 71-2084）的跨度内，而 2 型位于 aa 1003-2084 的跨度内。1 型 HA 活性的假定配体结合位于 aa 176-360，其结构类似于的 YadA。2 型 HA 活性的假定配体结合位于 aa 1003-1125，其结构类似于的 UspA1。1 型 HA 活性似乎是 Page 血清群特异性的，而 2 型似乎是 Kume 血清型特异性的。最后，对 HMTp210 的 aa 1-400 和 aa 1100-1600 跨度区域的序列分析对于的分子血清分型（Page 和修订后的 Kume 方案）可能是有用的。
