ABSTRACT

1. Leukocyte immunoglobulin-like receptor A5 (LILRA5) is a key molecule that regulates the immune system. However, the LILRA5 gene has not been characterised in avian species, including chickens. The present study aimed to identify and functionally characterise LILRA5 identified from two genetically disparate chicken lines, viz., Marek’s disease (MD)-resistant (R) line 6.3 and MD-susceptible (S) line 7.2.

2. Multiple sequence alignment and phylogenetic analyses confirmed that the identity and similarity homologies of amino acids of LILRA5 in chicken lines 6.3 and 7.2 ranged between 93% and 93.7%, whereas those between chicken and mammals ranged between 20.9% and 43.7% and 21.1% to 43.9%, respectively. The newly cloned LILRA5 from chicken lines 6.3 and 7.2 revealed high conservation and a close relationship with other known mammalian LILRA5 proteins.

3. The results indicated that LILRA5 from chicken lines 6.3 and 7.2 was associated with phosphorylation of Src kinases and protein tyrosine phosphatase non-receptor type 11 (SHP2), which play a regulatory role in immune functions. Moreover, the results demonstrated that LILRA5 in these lines was associated with the activation of major histocompatibility complex (MHC) class I and β2-microglobulin and induced the expression of the transporter associated with antigen processing. In addition, LILRA5 in both chicken lines activated and induced Janus kinase (JAK)–signal transducer and the activator of transcription (STAT), nuclear factor kappa B (NF-κB), phosphoinositide-3-kinase (PI3K)/protein kinase B (AKT) and the extracellular signal-regulated kinase (ERK)1/2 signalling pathways; toll-like receptors; and Th1-, Th2-, and Th17- cytokines.

4. The data suggested that LILRA5 has innate immune receptors essential for macrophage immune response and provide novel insights into the regulation of immunity and immunopathology.

摘要

1.白细胞免疫球蛋白样受体A5（LILRA5）是调节免疫系统的关键分子。但是，LILRA5基因尚未在禽类（包括鸡）中鉴定。本研究旨在鉴定和鉴定从两种遗传不同的鸡系中鉴定出的LILRA5，即耐马立克氏病（MD）系（R）6.3和MD易感病（S）7.2。

2.多重序列比对和系统发育分析证实，鸡系6.3和7.2中LILRA5氨基酸的同一性和相似性同源性在93％和93.7％之间，而鸡和哺乳动物之间的LILRA5氨基酸之间的同源性和同源性在20.9％和43.7％和21.1％之间分别达到43.9％。从鸡品系6.3和7.2新克隆的LILRA5显示出高度保守性，并且与其他已知的哺乳动物LILRA5蛋白密切相关。

3.结果表明，来自鸡系6.3和7.2的LILRA5与Src激酶和蛋白酪氨酸磷酸酶非受体11型（SHP2）的磷酸化有关，它们在免疫功能中起调节作用。此外，结果表明这些系中的LILRA5与主要组织相容性复合物（MHC）I类和β2-微球蛋白的活化有关，并诱导了与抗原加工有关的转运蛋白的表达。此外，LILRA5在鸡系中都激活和诱导了Janus激酶（JAK）-信号转导子和转录激活子（STAT），核因子κB（NF-κB），磷酸肌醇3-激酶（PI3K）/蛋白激酶B（AKT）和细胞外信号调节激酶（ERK）1/2信号通路；收费型受体；和Th1，Th2和Th17细胞因子。

4.数据表明，LILRA5具有巨噬细胞免疫反应所必需的先天性免疫受体，并为调节免疫和免疫病理学提供了新的见识。