Preferential accumulation of CD103+ T cells in human livers; its association with extrathymic T cells.

The Third Department of Internal Medicine, Toyama Medical and Pharmaceutical University, 2630 Sugitani, Toyama 930-0194, Japan.
Journal of Hepatology (Impact Factor: 9.86). 12/2003; 39(6):918-24. DOI: 10.1016/S0168-8278(03)00481-1
Source: PubMed

ABSTRACT CD103, a mucosal integrin alphaEbeta7, binds to E-cadherin expressed on hepatocytes and bile duct epithelium in the liver. Although CD103+ T cells are enriched in intestinal intraepithelial lymphocytes, the localization of those cells in the liver is unknown.
We investigated whether CD103+ cells are present in human livers, and how they are associated with the intrahepatic development of T cells by flow cytometry and immunohistochemistry.
Human livers contain significantly (P<0.001) higher percentages of CD103+ cells in CD4+ and CD8+ T cells (25.7+/-13.5 and 27.1+/-19.3%, respectively) than peripheral blood lymphocytes. Moreover, CD103+ cells in the liver, but not in peripheral blood, contained T cells with intermediate expression level of T cell receptor alphabeta. Those cells consist of mostly CD4+ and CD4-CD8- cells, and expressed low level of CD56 and interleukin-2 receptor beta chain in most of the population. These characteristics are distinct from natural killer T cells, which have been thought to be extrathymic T cells in human livers. Moreover, intrahepatic CD103+ cells expressed mRNA for recombination-activating gene-1, -2 and pre T cell receptor-alpha detected by reverse transcription-polymerase chain reaction.
CD103+ T cells are preferentially accumulated in human livers, and those T cells show characteristics of extrathymic T cells.

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