T-Cell Receptor γδ Diversity and Specificity of Intestinal Intraepithelial Lymphocytes: Analysis of IEL-Derived Hybridomas

The phenotype, T-cell antigen receptor (TCR) usage and specificity of intestinal intraepithelial lymphocytes (IEL), and hybridomas derived from IEL have been examined. In young conventionally reared mice, approximately 50% of the IEL express TCR αβ and 50% express TCR γδ, although there is considerable variation between individuals. Here we demonstrate that T-cell hybridomas can be prepared from freshly isolated BALB/c mouse IEL. The expressed TCR of these hybridomas reflects the TCR isotype distribution of the IEL population. Analysis of the γδ TCR expressed by the hybridomas demonstrates that IEL express a greater number of TCR V gene segments than has been reported for γδ T cells in several other epithelial sites. At least five types of γδ TCRs are expressed by a panel of BALB/c IEL hybridomas, although use of the γδ TCR V gene repertoire clearly is not random. Some TCR γδ cells and γδ hybridomas have been reported to recognize purified protein derivative (PPD); however, none of the IEL hybridomas secreted IL-2 in response to PPD. These data suggest that most TCR γδ IEL are not likely to be PPD reactive.