T cell receptor dynamism of mucosal and systemic CD4+ T cells in the course of an immune response to Escherichia coli heat-labile enterotoxin

Abstract

The changes in T cell receptor (TCR) Vβ expression, use, and clonality in mice orally challenged with Escherichia coli heat-labile enterotoxin (LT) were assessed. Use of the TCR Vβ family and clonality were significantly changed at the single-cell level. In Peyer's patches of treated mice, use of TCR Vβ6, Vβ8, and Vβ14 increased in CD4+CD44+ T cells, compared with use in nontreated mice. On the other hand, use of TCR Vβ1 and Vβ8 was enhanced in splenic CD4+CD44+ T cells. Intraepithelial lymphocytes isolated from LT-challenged mice showed expanded clonality (e.g., Vβ1, Vβ2, Vβ9, and Vβ18) and altered TCR Vβ use (e.g., Vβ15, Vβ16, and Vβ17). These findings reveal that oral administration of LT has distinct effects on mucosal versus systemic αβ T cells for induction of CD4+ T cells with selected Vβ use. This most likely reflects the function of LT as a mucosal modulator.