科學(xué)家在近期《自然—免疫學(xué)》雜志上撰文稱,，他們通過(guò)對(duì)小鼠進(jìn)行研究，發(fā)現(xiàn)了嬰兒的病毒感染抵抗力低的一種原因,。
自然殺傷（NK）細(xì)胞是一種能幫助抵抗病毒感染的白細(xì)胞。這種細(xì)胞在感染早期病毒數(shù)量有限的情況下具有非常重要的作用。
Yasmina Laouar等人注意到,，年幼小鼠和人類(lèi)嬰兒一樣，因?yàn)槿狈Τ墒斓腘K細(xì)胞而對(duì)病毒更敏感,。隨后,，他們發(fā)現(xiàn)TGF-β因子限制著未成熟NK細(xì)胞前體的增殖并阻礙其發(fā)育成熟。那些對(duì)TGF-β因子沒(méi)有應(yīng)答的新生和年幼小鼠能夠產(chǎn)生有效的NK細(xì)胞并抵御病毒感染,。雖然TGF-β因子一般被認(rèn)為是通過(guò)阻止炎癥發(fā)生來(lái)起到保護(hù)個(gè)體的作用,，但在幼年小鼠體內(nèi)，該因子卻會(huì)阻止那些保護(hù)小鼠不受病毒感染的有利免疫應(yīng)答反應(yīng),?？茖W(xué)家接下來(lái)還需通過(guò)進(jìn)一步試驗(yàn)確認(rèn)該結(jié)論能否同樣適用在人身上。（生物谷Bioon.com）
doi:10.1038/ni.2388
PMC:
PMID:
TGF-β is responsible for NK cell immaturity during ontogeny and increased susceptibility to infection during mouse infancy
Jeffrey P Marcoe, James R Lim, Keri L Schaubert, Nassima Fodil-Cornu, Marsel Matka, Alexandra L McCubbrey, Alexander R Farr, Silvia M Vidal Yasmina Laouar
A large gap in our understanding of infant immunity is why natural killer (NK) cell responses are deficient, which makes infants more prone to viral infection. Here we demonstrate that transforming growth factor-β (TGF-β) was responsible for NK cell immaturity during infancy. We found more fully mature NK cells in CD11cdnR mice, whose NK cells lack TGF-β receptor (TGF-βR) signaling. Ontogenic maturation of NK cells progressed faster in the absence of TGF-β signaling, which results in the formation of a mature NK cell pool early in life. As a consequence, infant CD11cdnR mice efficiently controlled viral infections. These data thus demonstrate an unprecedented role for TGF-β in ontogeny that can explain why NK cell responses are deficient early in life.
