Cytokine production following experimental implantation of xenogenic dermal collagen and polypropylene grafts in mice

Aim: We earlier showed that xenogenic Pelvicol (Bard, Olen, Belgium) implants induce a lesser inflammatory response than Prolene (Johnson and Johnson, Dilbeek, Belgium). The purpose of this study was to determine cytokine profiles in the host immune responses to Pelvicol in a mouse model. The hypothesis was that Pelvicol would induce a "T-helper2" (Th2) rather than T-helper1 (Th1) type of inflammatory response. Methods: Mice were implanted subcutaneously with Pelvicol or Prolene and the graft sites were harvested at 3 to 28 days. Histopathology was done and cytokine levels were determined by immunohistochemistry and RTPCR. Flow cytometry was used to identify which cell population contributed to the observed cytokine production profiles. Results: Pelvicol induced a decreased inflammation and displayed an increase in IL-10 and TGF-beta, but reduce of TNF-alpha and IFN-gamma, indicating a Th2 type dominated response as examined by immunohistochemistry and RT-PCR. Flow cytometry showed that the monocytes/maceophages were the main cell population responsible for production of these cytokines. Monocytes/maceophages from Pelvicol explants showed upregulated expression of IL-10 while Prolene explants expressed TNF-alpha. Conclusion: Pelvicol induced a Th2 type cytokinc-dominated immune response after subcutaneous implantation in mice.