在哺乳動(dòng)物妊娠期內(nèi)，母親和胎兒經(jīng)常通過胎盤交換關(guān)鍵的化學(xué)信號(hào),、營養(yǎng)和其他分子,。為了實(shí)現(xiàn)一個(gè)成功的妊娠（其標(biāo)準(zhǔn)是產(chǎn)下健康的后代），母親必須在免疫學(xué)的層次上耐受胎兒組織,。沒有免疫抑制,，胎兒和胎盤將被視為外來組織，被免疫系統(tǒng)攻擊,，導(dǎo)致妊娠以流產(chǎn)結(jié)束,。
Derek Wildman及其同事提出，這種類型的耐受是在哺乳動(dòng)物發(fā)展的早期進(jìn)化出的,。這組科學(xué)家研究了一種稱為galectin-1的抗炎癥蛋白的結(jié)構(gòu),，這種蛋白是在子宮等免疫反應(yīng)受到抑制的“免疫赦免”區(qū)域發(fā)現(xiàn)的。在研究了來自包括幾種靈長類動(dòng)物在內(nèi)的數(shù)種脊椎動(dòng)物的該蛋白質(zhì)后,，這組作這發(fā)現(xiàn)了這種蛋白結(jié)構(gòu)在有胎盤類哺乳動(dòng)物的進(jìn)化過程中是高度保守的,。這組科學(xué)家提出，galectin-1結(jié)構(gòu)的關(guān)鍵修改——這種修改可以讓它執(zhí)行其免疫功能——是在進(jìn)化的早期出現(xiàn)的,。相關(guān)論文發(fā)表在美國《國家科學(xué)院院刊》（PNAS）上,。（生物谷Bioon.com）
生物谷推薦原始出處：
PNAS，doi: 10.1073/pnas.0807606105,，Nandor Gabor Than,，Derek E. Wildman
Emergence of hormonal and redox regulation of galectin-1 in placental mammals: Implication in maternal–fetal immune tolerance
Nandor Gabor Than, Roberto Romero, Offer Erez, Amy Weckle, Adi L. Tarca, John Hotra, Asad Abbas, Yu Mi Han, Sung-Su Kim, Juan Pedro Kusanovic, Francesca Gotsch, Zhuocheng Hou, Joaquin Santolaya-Forgas, Kurt Benirschke, Zoltan Papp, Lawrence I. Grossman, Morris Goodman, and Derek E. Wildman
Galectin-1 is an anti-inflammatory lectin with pleiotropic regulatory functions at the crossroads of innate and adaptive immunity. It is expressed in immune privileged sites and is implicated in establishing maternal–fetal immune tolerance, which is essential for successful pregnancy in eutherian mammals. Here, we show conserved placental localization of galectin-1 in primates and its predominant expression in maternal decidua. Phylogenetic footprinting and shadowing unveil conserved cis motifs, including an estrogen responsive element in the 5′ promoter of LGALS1, that were gained during the emergence of placental mammals and could account for sex steroid regulation of LGALS1 expression, thus providing additional evidence for the role of galectin-1 in immune–endocrine cross-talk. Maximum parsimony and maximum likelihood analyses of 27 publicly available vertebrate and seven newly sequenced primate LGALS1coding sequences reveal that intense purifying selection has been acting on residues in the carbohydrate recognition domain and dimerization interface that are involved in immune functions. Parsimony- and codon model-based phylogenetic analysis of coding sequences show that amino acid replacements occurred in early mammalian evolution on key residues, including gain of cysteines, which regulate immune functions by redox status-mediated conformational changes that disable sugar binding and dimerization, and that the acquired immunoregulatory functions of galectin-1 then became highly conserved in eutherian lineages, suggesting the emergence of hormonal and redox regulation of galectin-1 in placental mammals may be implicated in maternal–fetal immune tolerance.
