CD28-CD4+ T-cell subpopulation is expanded in kidney allograft patients with long graft survival. To seek for the roles of CD28-CD4+ T cells in the long-term acceptance of kidney allografts, we characterized this population by analyzing cell surface molecules, TCR VΒ repertoire, mixed lymphocyte reaction (MLR), and cytokine production. The number of CD28-CD4+ T cells increased correlatively with time after transplantation in this group of patients. The CD28-CD4+ T cells did not express detectable levels of CD25, CD69, Vα24, or CTLA-4 but expressed heterogeneous amounts of CD45 RA on the surface. Freshly sorted CD28-CD4+ T cells revealed a restricted Vβ repertoire, whereas the Vβ usage of CD28+-CD4+ T cells from the same patients was much diversified. Expression levels of TGF-β and IFNγ gene were significantly higher in the CD28- CD4+ T cells than in the CD28+CD4+ T cells from the kidney allograft patients. These findings suggest that an oligoclonal CD28- CD4+ T-cell population is continuously activated in patients with long allograft survival, which may be linked with the long-term acceptance. Human Immunology 62, 1335-1345 (2001).
All Science Journal Classification (ASJC) codes
- Immunology and Allergy