Characterization of CTL Clones Specific for Single Antigen, H60 Minor Histocompatibility Antigen

BACKGROUND Disparities of Minor H antigens can induce graft rejection after MHC-matched transplantation. H60 has been characterized as a dominant antigen expressed on hematopoietic cells and considered to be an ideal model antigen for study on graft-versus-leukemia effect. METHODS Splenocytes from C57BL/6 mice immunized with H60 congenic splenocytes were used for establishment of H60-specific CTL clones. Then the clones were characterized for proliferation capacity and cytotoxicity after stimulation with H60. Clone #14, #15, and #23 were tested for the TCR binding avidity to H60-peptide/H-2K(b) and analyzed for TCR sequences. RESULTS H60-specific CTL clones showed different levels of proliferation capacity and cytotoxic activity to H60-stimulation. Clones #14, #15, and #23 showed high proliferation activity, high cytotoxicity, and low activities on both aspects, respectively, and have TCRs with different binding avidities to H60-peptide/H-2K(b) with t(1/2) values of 4.87, 6.92, and 13.03 minutes, respectively. The TCR usages were Vα12D-3-01+Jα11-01 and Vβ12-1-01+Dβ1-01+J2-7-01 for clone #14, Vα13D-1-02+Jα34-02 and Vβ13-1-02+Dβ2-01+Jβ2-7-01 for clone #15, and Vα16D+Jα45-01 and Vβ12-1-01+Dβ1-01+Jβ2-5-01 for clone #23. CONCLUSION The results will be useful for modeling GVL and generation TCR transgenic mouse.