Lee Hyang Mi, Hsieh Chyi-Song
Department of Internal Medicine, Division of Rheumatology, Washington University, St Louis, MO 63110, USA.
J Immunol. 2009 Aug 15;183(4):2261-6. doi: 10.4049/jimmunol.0901304. Epub 2009 Jul 20.
The CD4(+)CD8(+) (double positive, DP) stage of thymic development is thought to be the earliest period that generates natural Foxp3(+) regulatory T (Treg) cells important for the prevention of autoimmunity. However, we found that most Foxp3(+) DP cells identified by routine flow cytometry represent doublets comprised of Foxp3(-) DP and Foxp3(+) CD4(+)CD8(-) (CD4SP) cells. This was determined using analysis of flow cytometric height and width parameters, postsort contaminants, and thymocyte mixing studies. Temporal analysis of Treg cell development arising from bone marrow precursors in neonatal bone marrow chimeras suggested that Foxp3(+) DP cells are not a major percentage of Foxp3(+) thymocytes, and it supported the notion that most Treg cell development occurred at the immature HSA(high) CD4SP stage. Thus, these data demonstrate that the frequency of Foxp3(+) cells generated at the DP stage is much smaller than previously recognized, suggesting that additional thymocyte maturation may be required to facilitate efficient induction of Foxp3.
胸腺发育的CD4(+)CD8(+)(双阳性,DP)阶段被认为是产生对预防自身免疫至关重要的天然Foxp3(+)调节性T(Treg)细胞的最早时期。然而,我们发现通过常规流式细胞术鉴定的大多数Foxp3(+) DP细胞是由Foxp3(-) DP和Foxp3(+) CD4(+)CD8(-)(CD4SP)细胞组成的双联体。这是通过对流式细胞ometric高度和宽度参数、分选后污染物以及胸腺细胞混合研究的分析来确定的。对新生骨髓嵌合体中来自骨髓前体的Treg细胞发育的时间分析表明,Foxp3(+) DP细胞在Foxp(+)胸腺细胞中所占比例不大,这支持了大多数Treg细胞发育发生在未成熟的HSA(高) CD4SP阶段的观点。因此,这些数据表明,在DP阶段产生的Foxp3(+)细胞频率比以前认识到的要小得多,这表明可能需要额外的胸腺细胞成熟来促进Foxp3的有效诱导。