Histocompatibility Leukocyte Antigens, or HLAs, are one of the most polymorphic molecules in humans. This high degree of polymorphism endows HLA molecules with the ability to present a vast array of peptides, an essential trait for responding to ever-evolving pathogens. Unlike classical HLA molecules (HLA-Ia), some non-classical HLA-Ib molecules, including HLA-E, are almost monomorphic. Several studies show HLA-E can present self-peptides originating from the leader sequence of other HLA molecules, which signals to our immune system that the cell is healthy. Therefore, it was traditionally thought that the chief role of HLA-E in the body was in immune surveillance. However, there is emerging evidence that HLA-E is also able to present pathogen-derived peptides to the adaptive immune system, namely T cells, in a manner that is similar to classical HLA-Ia molecules. Here we describe the early findings of this less conventional role of HLA-E in the adaptive immune system and its importance for immunity.

中文翻译：

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HLA-E的非常规作用：少行驶的道路。

组织相容性白细胞抗原或HLA是人类中最多态的分子之一。这种高度的多态性赋予HLA分子以多种肽呈现的能力，这是对不断发展的病原体做出反应的基本特征。与经典HLA-Ia（HLA-Ia）不同，某些非经典HLA-Ib分子（包括HLA-E）几乎是单态的。多项研究表明，HLA-E可以呈现源自其他HLA分子前导序列的自身肽，这向我们的免疫系统发出信号，表明该细胞是健康的。因此，传统上认为HLA-E在体内的主要作用是免疫监视。但是，越来越多的证据表明，HLA-E还能够将病原体衍生的肽呈递给适应性免疫系统，即T细胞，以类似于经典HLA-1a分子的方式。在这里，我们描述了HLA-E在适应性免疫系统中这种不太常规的作用的早期发现及其对免疫的重要性。