Todd D J, Greiner D L, Rossini A A, Mordes J P, Bortell R
Department of Medicine, University of Massachusetts Medical School, 373 Plantation Street, Worcester, MA 01605, USA.
J Immunol. 2001 Oct 1;167(7):3600-9. doi: 10.4049/jimmunol.167.7.3600.
The intestinal lymphoid compartment of the rat is large and diverse, but the phenotype and functions of its constituent cell populations are not fully characterized. Using new methodology for the isolation and purification of rat intestinal intraepithelial lymphocytes (IELs), we previously identified a population of alphabeta- and gammadelta-TCR- NKR-P1A+ NK cells. These cells were almost completely restricted to the CD4-CD8- IEL population, and unlike peripheral NK cells in the rat, they were CD2-. We now report that rat intraepithelial NK (IENK) and peripheral NK cells are similar in morphology, in their ability to lyse NK-sensitive targets, and in their ability to suppress a one-way mixed lymphocyte culture. In contrast, however, intraepithelial and splenic NK cells differ markedly in two respects. First, IENK cells express high levels of ADP-ribosyltransferase 2 (a marker of regulatory T cells in the rat) and CD25, whereas peripheral NK cells do not. Second, unlike splenic NK cells, a substantial fraction of IENK cells appear to spontaneously secrete IL-4 and/or IFN-gamma. We conclude that the rat IEL compartment harbors a large population of NKR-P1A+CD3- cells that function as NK cells but display an activated phenotype and unusual cytokine profile that clearly distinguish them from splenic NK cells. Their phenotypic and functional characteristics suggest that these distinctive IENK cells may participate in the regulation of mucosal immunity.
大鼠的肠道淋巴区室庞大且多样，但其组成细胞群体的表型和功能尚未完全明确。利用新的方法分离和纯化大鼠肠道上皮内淋巴细胞（IEL），我们之前鉴定出一群αβ-和γδ-TCR-NKR-P1A⁺NK细胞。这些细胞几乎完全局限于CD4⁻CD8⁻IEL群体，并且与大鼠外周NK细胞不同，它们CD2⁻。我们现在报告，大鼠上皮内NK（IENK）细胞和外周NK细胞在形态、裂解NK敏感靶标的能力以及抑制单向混合淋巴细胞培养的能力方面相似。然而，相比之下，上皮内和脾NK细胞在两个方面存在显著差异。首先，IENK细胞高水平表达ADP-核糖基转移酶2（大鼠调节性T细胞的标志物）和CD25，而外周NK细胞不表达。其次，与脾NK细胞不同，相当一部分IENK细胞似乎自发分泌IL-4和/或IFN-γ。我们得出结论，大鼠IEL区室含有大量NKR-P1A⁺CD3⁻细胞，这些细胞发挥NK细胞的功能，但表现出活化的表型和异常的细胞因子谱，这明显将它们与脾NK细胞区分开来。它们的表型和功能特征表明，这些独特的IENK细胞可能参与黏膜免疫的调节。
