Hamad M, Klein J R
Department of Biological Science, University of Tulsa, Oklahoma 74104.
Immunology. 1994 Aug;82(4):611-6.
The phenotype and function of murine intestinal intraepithelial lymphocytes (IEL) was studied in a Percoll-fractionated preparation that consisted of low-density cells which migrated to the 40-50% Percoll interface (IEL-40), medium-density cells which migrated to the 50-55% interface (IEL-50), and high-density cells which migrated to the 55-70% interface (IEL-55). IEL-40 and IEL-50 cells, the subsets phenotypically most similar to mature IEL, consisted of CD3+ T cells that included CD4- CD8+ and CD4+ CD8+ cells; CD4+ CD8- cells were present only in the IEL-50 fraction. T-cell receptor (TcR)alpha beta and TcR gamma delta cells were present in both IEL-40 and IEL-50 fractions. In contrast, most IEL-55 were CD3-, heat-stable antigen (HSA)+ cells that were not B cells; some IEL-55 cells were CD3lo HSA- or CD3lo HSA+ suggesting that IEL-55 are immature T cells. TcR alpha beta but not TcR gamma delta was expressed in the IEL-55 fraction. All three IEL fractions consisted of both CD8 alpha alpha and CD8 alpha beta cells. There was considerable functional heterogeneity between the three IEL fractions such that CD3-induced proliferation was greatest for IEL-50 cells and least for IEL-55 cells; that activity correlated with the proportion of Thy-1+ cells within the fractions. Both IEL-40 and IEL-50 fractions contained activated cytotoxic T lymphocytes (CTL) that were 8-16-fold more lytic than IEL-55 cells. That IEL-55 cells may be precursors of some IEL-40 and IEL-50 cells was demonstrated by a shift in cell density and by an increase in proportions of cells expressing markers of IEL-40 and IEL-50 cells following in vitro stimulation via CD3. The relevance of these findings to differences in functional activities reported for murine IEL is discussed.
在一种经Percoll分层分离的制剂中研究了小鼠肠道上皮内淋巴细胞（IEL）的表型和功能，该制剂由迁移至40%-50%Percoll界面的低密度细胞（IEL-40）、迁移至50%-55%界面的中密度细胞（IEL-50）和迁移至55%-70%界面的高密度细胞（IEL-55）组成。IEL-40和IEL-50细胞是表型上与成熟IEL最相似的亚群，由包括CD4-CD8+和CD4+CD8+细胞的CD3+T细胞组成；CD4+CD8-细胞仅存在于IEL-50组分中。T细胞受体（TcR）αβ和TcRγδ细胞存在于IEL-40和IEL-50组分中。相比之下，大多数IEL-55是CD3-、热稳定抗原（HSA）+细胞，不是B细胞；一些IEL-55细胞是CD3loHSA-或CD3loHSA+，表明IEL-55是未成熟T细胞。TcRαβ而非TcRγδ在IEL-55组分中表达。所有三个IEL组分均由CD8αα和CD8αβ细胞组成。三个IEL组分之间存在相当大的功能异质性，使得CD3诱导的增殖对IEL-50细胞最大，对IEL-55细胞最小；该活性与各组分中Thy-1+细胞的比例相关。IEL-40和IEL-50组分均含有活化的细胞毒性T淋巴细胞（CTL），其细胞毒性比IEL-55细胞高8-16倍。通过细胞密度的变化以及体外经CD3刺激后表达IEL-40和IEL-50细胞标志物的细胞比例增加，证明IEL-55细胞可能是一些IEL-40和IEL-50细胞的前体。讨论了这些发现与报道的小鼠IEL功能活性差异的相关性。
