BACKGROUND: The interaction between CD40 and its ligand CD40L is essential for the development and maintenance of vigorous immunity. We have sought to determine: (i) whether a heightened level of CD40L transcripts is evident during acute allograft rejection and (ii) the kinetics of CD40L gene expression during allograft rejection. METHODS: By using quantitative reverse transcriptase-assisted polymerase chain reaction techniques, we found that heightened CD40L gene expression is a correlate of acute human renal allograft rejection (P<0.01). RESULTS: In a murine model of MHC-mismatched islet allografts, our results showed that CD40L transcripts were rarely detected at day 2 after transplantation, but were remarkably heightened at day 5 after transplantation. The transcript levels then steadily increased and peaked at the time of rejection. CONCLUSION: These data suggest that therapy aimed at blocking the CD40 to CD40L interaction should be applied during the immediate posttransplant period.
BACKGROUND: The interaction between CD40 and its ligand CD40L is essential for the development and maintenance of vigorous immunity. We have sought to determine: (i) whether a heightened level of CD40L transcripts is evident during acute allograft rejection and (ii) the kinetics of CD40L gene expression during allograft rejection. METHODS: By using quantitative reverse transcriptase-assisted polymerase chain reaction techniques, we found that heightened CD40L gene expression is a correlate of acute human renal allograft rejection (P<0.01). RESULTS: In a murine model of MHC-mismatched islet allografts, our results showed that CD40L transcripts were rarely detected at day 2 after transplantation, but were remarkably heightened at day 5 after transplantation. The transcript levels then steadily increased and peaked at the time of rejection. CONCLUSION: These data suggest that therapy aimed at blocking the CD40 to CD40L interaction should be applied during the immediate posttransplant period.