Helper T-cell type 1 or type 2 function of xeno-MHC-restricted T-cell clones in a direct xenoantigen recognition

Abstract

There have been several reports that xeno-MHC-restricted T-cells have a cytotoxic function through a direct xenoantigen recognition, but yet no report that they have a helper function. Previously we showed that both xeno-MHC-restricted CD4 + and CD8 + T-cells recognized xenoantigens directly in a mouse anti-rat combination. In this study, we investigated whether or not xeno-MHC-restricted T-cells had a helper function. Mouse T-cell clones recognizing rat antigens directly were derived from T-cell lines using the limiting dilution method. Phenotype, cytotoxic activity and cytokine production of these clones were analyzed by flow cytometry, 51Cr release assay and ELISA, respectively. Rat-MHC class I-restricted mouse CD8 + T-cell clones showed a specific cytotoxic activity against rat antigens. One CD4 + clone produced IL-4 and IL-10, and the other CD4 + clone produced not T-helper (Th) 2 cytokine but TNF-α. Our results suggested that xeno-MHC class I-restricted CD8 + T-cells should have a cytotoxic function, and xeno-MHC class II-restricted CD4 + T-cells should have either Th1 or Th2 function.