?Pennsylvania州立大學(xué)獸醫(yī)學(xué)學(xué)院的研究者發(fā)現(xiàn),，魚(yú)和哺乳動(dòng)物B細(xì)胞的原始模型和白細(xì)胞的免役系統(tǒng)存在獨(dú)特的進(jìn)化相關(guān)性。他們的研究把哺乳動(dòng)物適當(dāng)?shù)拿庖巯到y(tǒng)（在這里B細(xì)胞產(chǎn)生抗體抵抗感染）與魚(yú)更原始的先天免疫性（在這里B細(xì)胞參與吞噬作用）在進(jìn)化上的關(guān)聯(lián)性聯(lián)系起來(lái),，B細(xì)胞參與的吞噬作用是免疫系統(tǒng)的細(xì)胞攝取外源顆粒和微生物的過(guò)程,。
??這項(xiàng)研究在線出版在自然免疫學(xué)雜志上，將其作為十月期刊封面代表哺乳動(dòng)物免疫系統(tǒng)一個(gè)相當(dāng)大的進(jìn)化步驟,，同時(shí)也為魚(yú)類(lèi)疫苗的發(fā)展提供了一個(gè)潛在的新策略,。
??病理學(xué)系J. Oriol Sunyer教授說(shuō)：“在調(diào)查魚(yú)B細(xì)胞時(shí)，我們發(fā)現(xiàn)他們主動(dòng)攻擊和吃外源異物,，根據(jù)當(dāng)前的定論,，這種行為在B細(xì)胞中不應(yīng)該發(fā)生,，我認(rèn)為這為免疫防御最原始的形式之間的聯(lián)系提供了一個(gè)很好的證據(jù)，魚(yú),，以及更高等的人類(lèi)和吉他的哺乳動(dòng)物都存在免疫應(yīng)答而幸存,。”
??大約在400萬(wàn)年前，現(xiàn)代魚(yú)的最古老祖先脫離了進(jìn)化途徑而成為現(xiàn)代哺乳動(dòng)物最古老的祖先,，在現(xiàn)代哺乳動(dòng)物中,，B細(xì)胞積極響應(yīng)免疫系統(tǒng)，重要是產(chǎn)生抗體識(shí)別外源顆粒和微生物所帶來(lái)的破壞,。哺乳動(dòng)物有吞噬細(xì)胞,，但他們是區(qū)別于驅(qū)動(dòng)其他白細(xì)胞復(fù)雜的相互作用的特有少數(shù)細(xì)胞。
??Sunyer和同事在檢查虹鱒魚(yú)和鯰魚(yú)時(shí)發(fā)現(xiàn)了以前不受懷疑的B細(xì)胞的活性,。研究者認(rèn)為,，攻擊性B細(xì)胞大約占了魚(yú)類(lèi)所有免疫細(xì)胞的30%~40%，而吞噬細(xì)胞在哺乳動(dòng)物免疫細(xì)胞中僅僅占有很小的部分,。進(jìn)一步的研究表明,，兩棲動(dòng)物B細(xì)胞保留著消化特性的重要部分。
??Sunyer說(shuō)：“兩棲類(lèi)和魚(yú)類(lèi)的免疫系統(tǒng)不比我們的免疫系統(tǒng)先進(jìn),，只有你有一個(gè)未發(fā)育的合適免疫系統(tǒng)時(shí),，才有助于更多的吞噬細(xì)胞來(lái)補(bǔ)償，這就是400多萬(wàn)年前發(fā)生在魚(yú)身上的現(xiàn)象,。”
??在過(guò)去,，研究更“原始”物種免疫系統(tǒng)的研究者通過(guò)研究發(fā)現(xiàn)了人類(lèi)和其他哺乳動(dòng)物與免疫應(yīng)答有關(guān)的關(guān)鍵分子和途徑。例如,，B細(xì)胞本身在1960年首次在雞中發(fā)現(xiàn),。根據(jù)Sunyer，Penn不僅對(duì)魚(yú)免疫細(xì)胞的進(jìn)化和功能的理解有著重要作用,，而且也為哺乳動(dòng)物B細(xì)胞新作用提供了新思路,。
??“在這點(diǎn)上,，我們不能排除吞噬性B細(xì)胞小亞群的可能性,，或許，魚(yú)類(lèi)現(xiàn)在的殘留在哺乳動(dòng)物體內(nèi)仍然存在,，”Snuyer說(shuō),。
??他們這些發(fā)現(xiàn)在農(nóng)業(yè)上也有關(guān)聯(lián)。例如,，當(dāng)前農(nóng)場(chǎng)鮭魚(yú)疫苗適合魚(yú)的免疫應(yīng)答,，這項(xiàng)研究比以前認(rèn)為的具有更小的魚(yú)類(lèi)免疫系統(tǒng)。
??Sunyer說(shuō)：“如果我們能產(chǎn)生刺激吞噬性B細(xì)胞對(duì)感染作出應(yīng)答的疫苗的話,，我們就能駕御魚(yú)類(lèi)免疫性的強(qiáng)度,，長(zhǎng)期來(lái)看,，農(nóng)業(yè)越發(fā)達(dá)，對(duì)魚(yú)產(chǎn)生的環(huán)境噪音就越大,，所以就需要更好的疫苗使魚(yú)類(lèi)免受毀壞增加漁民的收入,。”
??毫無(wú)疑問(wèn)，盡管行為不同,，魚(yú)B細(xì)胞代表著哺乳動(dòng)物B細(xì)胞少許先進(jìn)的版本,。Snuyer發(fā)現(xiàn)細(xì)胞結(jié)構(gòu)被用來(lái)限定存在于魚(yú)B細(xì)胞的人類(lèi)B細(xì)胞，這就是為什么他們一開(kāi)始不能被當(dāng)作B細(xì)胞標(biāo)志的原因,。
??Sunyer說(shuō)：“這里,，我們有免疫系統(tǒng)、原始吞噬細(xì)胞的部分照片,，免疫系統(tǒng)在過(guò)去比現(xiàn)在扮演了更復(fù)雜的角色,，我們要通過(guò)在所有生物體中間研究免疫系統(tǒng)來(lái)獲悉我們的健康還需要一定的時(shí)間。”
英文原文：
Link between Fish and Mammal Immune Systems Revealed by Killer B cells
An evolutionary link between the immune systems of fish and mammals in the form of a primitive version of B cells, white blood cells of the immune system has been discovered by researchers from the University of Pennsylvania School of Veterinary Medicine.
Their studies link the evolution of the adaptive immune system in mammals, where B cells produce antibodies to fight infection, to the more primitive innate immunity in fish, where they found that B cells take part in phagocytosis (literally: cell eating), the process by which cells of the immune system ingest foreign particles and microbes.
The finding, which appears in the online version of Nature Immunology and will be featured on the cover of the October issue, represents a sizeable evolutionary step for the mammalian immune system and offers a potential new strategy for developing much-needed fish vaccines. "When examining fish B cells we see them actively attacking and eating foreign bodies, which is a behavior that, according to the current dogma, just shouldn't happen in B cells," said J. Oriol Sunyer, a professor in Penn Vet's Department of Pathobiology. "I believe it is evidence for a very real connection between the most primitive forms of immunological defense, which has survived in fish, and the more advanced, adaptive immune response seen in humans and other mammals."
About 400 million years ago, the earliest ancestors of modern fish split off of the evolutionary pathway that became the earliest ancestors of modern mammals. In modern mammals, the B cell is a highly adapted part of the immune system chiefly responsible for, among other things, the creation of antibodies that tag foreign particles and microbes for destruction. Mammals have phagocytic cells, but they are a specialized few cells identified apart from the complex interactions that drive other white blood
