THE EFFECT OF AUTOLOGOUS AND HETEROLOGOUS ANTIMICROBIAL PEPTIDES EXTRACT ON RABBIT AND OVINE LEUKOCYTES EVALUATED DURING REPAIR PROCESS.

Antimicrobial peptides (AMPs) appeared to be a new approach both against microorganisms and for regulation of inflammatory and repair process. To evaluate their potential usefulness in regenerative medicine we prepared different extracts of neutrophil-derived AMPs, from rabbit, ovine or porcine blood, which contained AMPs of different composition, mainly defensins, cathelicidins and the fragments thereof. Then, we assessed the influence of different AMPs extracts on activity of neutrophils and monocyte-derived macrophages (MDM) in vitro. For this purpose these cells were obtained from experimental animals, rabbits or sheep submitted to different orthopedic procedures such as insertion of titanium implant into the tibial defect, implantation of biomaterials into osteochondral or bone defect or osteochondral transplantation. Stimulation of cultured cells was autologous or heterologous dependently on origin of AMPs extract and the species of experimental animal. The neutrophil activity was assessed on the basis of release of enzymes from azurophilic and secondary granules and free radicals generation. MDM functional assessment was done on the basis of NO and superoxide generation and arginase activity, additionally morphological changes were evaluated in these cell cultures. Our results indicated that the origin of AMPs extract is crucial for its activity, autologous extracts stimulated anti-inflammatory responses, whereas heterologous extracts acted pro-inflammatory on neutrophils and macrophages in vitro. These results could be considered during introduction of new preparations in regenerative medicine.