Induction and Functional Analysis of Ƒáƒâtcr-bearing T Cells from Human Tonsil by Streptococcus Pyogenes Stimulation

The killer cell characteristics of ƒÁƒÂTCR-bearing T cells induced from human tonsil by streptococcus pyogenes stimulation were examined. Immunohistologic staining of tonsil showed that ƒÁƒÂ TCR-bearing T cells were mainly located in the interfollicular area connected with stratified squamous epithelium. Streptococcus pyogenes could induce the proliferation of ƒÁƒÂTCRbearing T cells from tonsil in the presence of low-dose of IL-2. This streptococcus pyogenes-induced ƒÁƒÂTCR-bearing T cell proliferation was likely to be independent on the IL-2/IL-2R system since an obvious inhibition was not observed with anti-IL2 and anti-IL-2R mAbs. More importantly, these ƒÁƒÂTCR-bearing T cells exhibited cell-mediated cytotoxic activity in a 4hr 51 Cr-release assay. In addition, immunocytochemical staining revealed that these cells contained a killer protein perforin. These results demonstrate that y6TCRbearing T cells from tonsil exhibit typical killer cell characteristics. These data also suggest that ƒÁƒÂ TCR-bearing T cells in human tonsil may play a cytotoxic role in protecting the integrity of tonsil from infection.