Identification and Regulation of TCRαß+CD8αα+ Intraepithelial Lymphocytes in Murine Oral Mucosa.

ABSTRACT

TCRαß+CD8αα+ intraepithelial lymphocytes (IELs) are abundant in gastrointestinal (GI) tract and play an important role in regulation of mucosal immunity and tolerance in the gut. However, it is unknown whether TCRαß+CD8αα+ IELs exist in the oral mucosa and if yes, what controls their development. We here identified and characterized TCRαß+CD8αα+ IELs from the murine oral mucosa. We showed that the number and function of TCRαß+CD8αα+ IELs were regulated by TGF-ß. We further revealed that oral TCRαß+CD8αα+ IELs could be altered under systemic inflammatory conditions and by antibiotic treatment at the neonatal age of the mice. Our findings have revealed a previously unrecognized population of oral IELs that may regulate oral mucosal immune responses.