INTRAEPITHELIAL LYMPHOCYTES IN COLON HAVE SIMILAR PROPERTIES TO INTRAEPITHELIAL LYMPHOCYTES IN SMALL-INTESTINE AND HEPATIC INTERMEDIATE TCRCELLS

Recently, properties of intraepithelial lymphocytes (IEL) in the colon (C-IEL) have been analyzed in comparison with those of IEL in the sma ll intestine (SI-IEL). We compared the properties of C-IEL with those of SI-IEL and hepatic intermediate TCR cells, two other types of extra thymic T cells. C-IEL and intermediate TCR cells contain many NK1(+)T cells, although SI-IEL contain few. V gamma and V delta usage of C-IEL was the same as that of SI-IEL, and that of intermediate TCR cells wa s different. C-IEL responded to Con A while SI-IEL did not. As to adhe sion molecules, C-IEL include both extrathymic and thymus-originated t ype T cells. With age, TCR-alpha beta(+)CD4(+)CD8(+) cells do not incr ease among C-IEL but do increase among SI-IEL. IL-2R beta(+) or CD4(-) CD8(-) C-IEL increase as observed in the liver. These results indicate that these organ-specific T cells have different roles at their respe ctive sites and that they may be of different lineages.