Investigation of cynomolgus monkey complement.

Abstract Background The cynomolgus monkey is one of the most popular recipient animals in xenotransplantation experiments. However, studies of the cynomolgus monkey complement are rare. In the present study, based on the study that compared the hemolytic complement titer in cynomolgus monkeys with that in humans, the complement regulatory function of human decay accelerating factor (CD55) in both human and cynomolgus monkey sera was studied. Methods Hemolytic complement titers in cynomolgus monkeys were calculated using the same methods as are used in humans. Next, the complement regulatory function of human DAF (CD55) in cynomolgus monkey serum was studied using porcine endothelial cells (PECs) and human DAF. Results Of the complement titers tested, such as CH50, ACH50, C4, C2, and C3, the values were relatively high, except for the C4 titer. Human DAF on the surface of PEC resulted in nearly identical complement regulatory function in the human and cynomolgus monkey sera. Conclusions Human DAF showed nearly the same complement regulatory function in both human and cynomolgus monkey sera.