Abstract
To study how intestinal intraepithelial lymphocytes (IEL) are affected by orally ingested antigen, the phenotypes and responses of the IEL in mice expressing a transgenic T cell receptor αβ (TCR αβ) specific for ovalbumin (OVA) were analyzed after feeding OVA. In the OVA-fed mice, the abundance of αβ-IEL as a proportion of the total IEL population increased and the frequency of CD4+ cells increased within the TCR αβ+ IEL population. CD4+ IEL from OVA-fed transgenic mice proliferated in vitro more markedly in response to antigen stimulation than IEL from mice fed the control diet. These results indicate that antigen-specific proliferation of CD4+ IEL was amplified as a result of oral administration of antigen.