Cobra venom factor

To minimize the risk of rejection, an immunosuppression regimen informed by current practices in clinical transplantation, and described for use in xeno-support of human lungs, was used (Figure 1B).^{14 ,15 (link)} At 4 hours before cross-circulation, xeno-support swine were anesthetized, intubated, and administered cobra venom factor (1 mg; Sigma-Aldrich) to deplete complement activity.^{16 (link)} Intravenous diphenhydramine (50 mg; West Ward) and methylprednisolone (1 g; Pfizer) were administered to limit the inflammatory response associated with cobra venom factor. Intravenous tacrolimus (5 mg; Astellas) and mycophenolate (500 mg; Genentech) were also administered before reperfusion and redosed every 12 hours (Supplemental Figure S1C, http://links.lww.com/HEP/F706). methylprednisolone (125 mg; Pfizer) was readministered every 8 hours after the initial dosage.

10-day-old pups of both sexes were given an IP inoculation containing 10² CFU of Spn suspended in 40 μl of PBS, as described previously [27 (link)]. Pups were euthanized 24 hrs post-inoculation, and blood was collected via cardiac puncture and cultured to assess for bacteremia. To select for a variant expressing increased CPS, the inoculum was increased to 10⁷ CFU. To verify its importance in invasive infection, complement was depleted in 9-day-old pups of both sexes by IP administration of 20 ug of cobra venom factor (or PBS as a vehicle control) (Sigma-Aldrich) in 20 μL in PBS. The pups were then inoculated with Spn in the same manner as described above 24 hrs later. At 24 hrs post-inoculation, the pups were euthanized to perform blood collection and culture.