Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada.
Dev Comp Immunol. 2011 Sep;35(9):1008-16. doi: 10.1016/j.dci.2011.02.011. Epub 2011 Mar 4.
The role of the duck as the natural host and reservoir of influenza and efforts to vaccinate ducks during recent outbreaks of avian influenza has renewed interest in the duck antibody response. Ducks have unique antibody structures and expression, with consequences for their function. Aspects of immunoglobulin genetics, gene expression, and antibody function will be reviewed in the context of the duck immune response to influenza. Ducks have three immunoglobulin isotypes, IgM, IgA and IgY in translocon arrangement. The order of heavy chain genes in the locus is unusual, IGHM, IGHA and IGHY, with IGHA in inverse transcriptional orientation. IgH and IgL gene rearrangement in ducks involves limited V, (D) and J element recombination and diversity is generated by gene conversion from pseudogenes. IgY, the functional equivalent of IgG, is produced in two secreted forms, a full-length form and one lacking the third and fourth C region domains, which predominates later in the immune response and lacks the biological effector functions of IgG. The unusual features of duck antibodies may contribute to weak antibody responses and the perpetuation of the virus in this animal reservoir.
鸭作为流感的天然宿主和储主，以及在最近禽流感爆发期间对鸭进行疫苗接种的努力，重新引起了人们对鸭抗体反应的兴趣。鸭具有独特的抗体结构和表达，这对其功能有影响。本文将在鸭对流感免疫反应的背景下，综述免疫球蛋白遗传学、基因表达和抗体功能等方面。鸭有三种免疫球蛋白同种型，即转导器排列的 IgM、IgA 和 IgY。基因座中重链基因的顺序很不寻常，IGHM、IGHA 和 IGHY，IGHA 呈反向转录方向。鸭的 IgH 和 IgL 基因重排在涉及有限的 V、（D）和 J 元件重组，多样性由假基因的基因转换产生。IgY 是 IgG 的功能等价物，以两种分泌形式产生，全长形式和缺少第三和第四个 C 区结构域的形式，后者在免疫反应后期占主导地位，缺乏 IgG 的生物学效应功能。鸭抗体的这些不寻常特征可能导致抗体反应较弱，并使病毒在这种动物储主中持续存在。
