Santana Felix L, Estrada Karel, Ortiz Ernesto, Corzo Gerardo
Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, A.P. 510-3, Cuernavaca Mor., 62250, Mexico.
Unidad de Secuenciación Masiva y Bioinformática, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, Mexico.
Peptides. 2021 Feb;136:170473. doi: 10.1016/j.peptides.2020.170473. Epub 2020 Dec 10.
One of the major families of host defense peptides (HDPs) in vertebrates are β-defensins. They constitute important components of innate immunity and have remained an interesting topic of research for more than two decades. While many β-defensin sequences in mammals and birds have been identified and their properties and functions characterized, β-defensin peptides from other groups of vertebrates, particularly reptiles, are still largely unexplored. In this review, we focus on reptilian β-defensins and summarize different aspects of their biology, such as their genomic organization, evolution, structure, and biological activities. Reptilian β-defensin genes exhibit similar genomic organization to birds and their number and gene structure are variable among different species. During the evolution of reptiles, several gene duplication and deletion events have occurred and the functional diversification of β-defensins has been mainly driven by positive selection. These peptides display broad antimicrobial activity in vitro, but a deeper understanding of their mechanisms of action in vivo, including their role as immunomodulators, is still lacking. Reptilian β-defensins constitute unique polypeptide sequences to expand our current understanding of innate immunity in these animals and elucidate core biological functions of this family of HDPs across amniotes.
脊椎动物宿主防御肽（HDPs）的主要家族之一是β-防御素。它们是先天免疫的重要组成部分，二十多年来一直是一个有趣的研究课题。虽然哺乳动物和鸟类中的许多β-防御素序列已被鉴定，其特性和功能也已得到表征，但来自其他脊椎动物群体，特别是爬行动物的β-防御素肽在很大程度上仍未被探索。在这篇综述中，我们聚焦于爬行动物β-防御素，并总结其生物学的不同方面，如它们的基因组组织、进化、结构和生物活性。爬行动物β-防御素基因表现出与鸟类相似的基因组组织，并且其数量和基因结构在不同物种间存在差异。在爬行动物的进化过程中，发生了几次基因复制和缺失事件，β-防御素的功能多样化主要由正选择驱动。这些肽在体外显示出广泛的抗菌活性，但对其在体内的作用机制，包括其作为免疫调节剂的作用，仍缺乏更深入的了解。爬行动物β-防御素构成了独特的多肽序列，以扩展我们目前对这些动物先天免疫的理解，并阐明跨羊膜动物的这一HDP家族的核心生物学功能。
