CD154/CD40 blockade combined with donor specific transfusion remains one of the most effective therapies in prolonging allograft survival. Despite this, the mechanisms by which these pathways synergize to prevent rejection are not completely understood. Utilizing a BALB/c (H2-Kd) to B6 (H2-Kb) fully allogeneic skin transplant model system, we performed a detailed longitudinal analysis of the kinetics and magnitude of CD8+ T cell expansion and differentiation in the presence of CD154/CD40 pathway blockade. Results demonstrated that treatment with anti-CD154 vs. DST had distinct and opposing effects on activated CD44high CD62Llow CD8+ T cells in skin graft recipients. Specifically, CD154 blockade delayed alloreactive CD8+ T cell responses, while DST accelerated them. DST inhibited the differentiation of alloreactive CD8+ T cells into multi-cytokine producing effectors, while CD40/CD154 blockade led to the diminution of the KLRG-1low long-lived memory precursor population compared with either untreated or DST treated animals. Moreover, only CD154 blockade effectively inhibited CXCL1 expression and neutrophil recruitment into the graft. When combined, anti-CD154 and DST acted synergistically to profoundly diminish the absolute number of IFN-γ producing alloreactive CD8+ T cells, and intra-graft expression of inflammatory chemokines. These findings demonstrate that the previously described ability of anti-CD154 and DST to result in alloreactive T cell deletion involves both delayed kinetics of T cell expansion and differentiation and inhibited development of KLRG-1low memory precursor cells.
Parker DC, Greiner DL, Phillips NE, Appel MC, Steele AW, et al. (1995) Survival of mouse pancreatic islet allografts in recipients treated with allogeneic small lymphocytes and antibody to CD40 ligand. Proc Natl Acad Sci U S A 92: 9560–9564.
Markees TG, Phillips NE, Gordon EJ, Noelle RJ, Shultz LD, et al. (1998) Long-term survival of skin allografts induced by donor splenocytes and anti-CD154 antibody in thymectomized mice requires CD4(+) T cells, interferon-gamma, and CTLA4. J Clin Invest 101: 2446–2455.
Zheng XX, Markees TG, Hancock WW, Li Y, Greiner DL, et al. (1999) CTLA4 signals are required to optimally induce allograft tolerance with combined donor-specific transfusion and anti-CD154 monoclonal antibody treatment. J Immunol 162: 4983–4990.
Hancock WW, Sayegh MH, Zheng XG, Peach R, Linsley PS, et al. (1996) Costimulatory function and expression of CD40 ligand, CD80, and CD86 in vascularized murine cardiac allograft rejection. Proc Natl Acad Sci U S A 93: 13967–13972.
Quezada SA, Fuller B, Jarvinen LZ, Gonzalez M, Blazar BR, et al. (2003) Mechanisms of donor-specific transfusion tolerance: preemptive induction of clonal T-cell exhaustion via indirect presentation. Blood 102: 1920–1926.
Margenthaler JA, Kataoka M, Flye MW (2003) Donor-specific antigen transfusion-mediated skin-graft tolerance results from the peripheral deletion of donor-reactive CD8+ T cells. Transplantation 75: 2119–2127.
van Maurik A, Fazekas de St Groth B, Wood KJ, Jones ND (2004) Dependency of direct pathway CD4+ T cells on CD40-CD154 costimulation is determined by nature and microenvironment of primary contact with alloantigen. J Immunol 172: 2163–2170.
Joshi NS, Cui W, Chandele A, Lee HK, Urso DR, et al. (2007) Inflammation directs memory precursor and short-lived effector CD8(+) T cell fates via the graded expression of T-bet transcription factor. Immunity 27: 281–295.
Floyd TL, Koehn BH, Kitchens WH, Robertson JM, Cheeseman JA, et al. (2011) Limiting the amount and duration of antigen exposure during priming increases memory T cell requirement for costimulation during recall. J Immunol 186: 2033–2041.
Wherry EJ, Blattman JN, Murali-Krishna K, van der Most R, Ahmed R (2003) Viral persistence alters CD8 T-cell immunodominance and tissue distribution and results in distinct stages of functional impairment. J Virol 77: 4911–4927.
Shen X, Reng F, Gao F, Uchida Y, Busuttil RW, et al. (2010) Alloimmune activation enhances innate tissue inflammation/injury in a mouse model of liver ischemia/reperfusion injury. Am J Transplant 10: 1729–1737.
Zhang T, Fresnay S, Welty E, Sangrampurkar N, Rybak E, et al. (2011) Selective CD28 blockade attenuates acute and chronic rejection of murine cardiac allografts in a CTLA-4-dependent manner. Am J Transplant 11: 1599–1609.