RESUMO
Although xenografts are one of the most attractive strategies for overcoming the shortage of organ donors, cellular rejection by macrophages is a substantial impediment to this procedure. It is well known that macrophages mediate robust immune responses in xenografts. Macrophages also express various inhibitory receptors that regulate their immunological function. Recent studies have shown that the overexpression of inhibitory ligands on porcine target cells results in the phosphorylation of tyrosine residues on intracellular immunoreceptor tyrosine-based inhibitory motifs on macrophages, leading to the suppression of xenogenic rejection by macrophages. It has also been reported that myeloid-derived suppressor cells, a heterogeneous population of immature myeloid cells, suppress not only NK and cytotoxic T lymphocyte cytotoxicity but also macrophage-mediated cytotoxicity. This review is focused on the recent findings regarding strategies for inhibiting xenogenic rejection by macrophages.
Assuntos
Rejeição de Enxerto/prevenção & controle , Sobrevivência de Enxerto , Imunidade Celular , Macrófagos/imunologia , Transplante Heterólogo/efeitos adversos , Animais , Antígeno CD47/genética , Antígeno CD47/imunologia , Antígeno CD47/metabolismo , Rejeição de Enxerto/genética , Rejeição de Enxerto/imunologia , Rejeição de Enxerto/metabolismo , Xenoenxertos/imunologia , Antígenos de Histocompatibilidade Classe I/genética , Antígenos de Histocompatibilidade Classe I/imunologia , Antígenos de Histocompatibilidade Classe I/metabolismo , Humanos , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/metabolismo , Macrófagos/metabolismo , Células Supressoras Mieloides/imunologia , Células Supressoras Mieloides/metabolismo , Células Supressoras Mieloides/transplante , Fagocitose , Proteína D Associada a Surfactante Pulmonar/genética , Proteína D Associada a Surfactante Pulmonar/imunologia , Proteína D Associada a Surfactante Pulmonar/metabolismo , Sialiltransferases/genética , Sialiltransferases/imunologia , Sialiltransferases/metabolismo , Transdução de Sinais , Resultado do Tratamento , beta-D-Galactosídeo alfa 2-6-SialiltransferaseRESUMO
PURPOSE: Various strategies, such as the generation of alpha-1,3-galactosyltransferase knocked-out pigs and CD55 transgenic pigs, have been investigated to inhibit pig to human xenogeneic rejection. Our aim is to develop strategies to overcome the hurdle of not only hyper acute rejection, but also that of cellular xenogeneic rejection (CXR). Although macrophages have been well known to play a critical role in CXR, monocyte/macrophage-mediated xenogeneic rejection has not been well studied. In this study, we evaluated the effect of CD200 in xenogeneic rejection by macrophages. METHODS: Naïve swine endothelial cells (SEC) and SEC/CD200 were co-cultured with M0 macrophages and the cytotoxicity was measured by a WST-8 assay. The phagocytosis of SEC and SEC/CD200 by macrophages was analyzed by flow cytometry. RESULTS: While CD200 failed to suppress a significant amount of cytotoxicity against SEC by monocytes, M0 macrophage-mediated cytotoxicity was significantly suppressed by human CD200. The phagocytosis by M0 macrophages was also tested. The phagocytosis assay revealed that human CD200 suppresses M0 macrophage-mediated phagocytosis. CONCLUSIONS: Our findings indicate that human CD200 suppresses the xenogeneic rejection by CD200R+ macrophages and that the generation of hCD200 transgenic pigs for use in xenografts is very attractive for preventing the macrophage-mediated rejection.
Assuntos
Antígenos CD/fisiologia , Citotoxicidade Imunológica/genética , Células Endoteliais/imunologia , Macrófagos/imunologia , Fagocitose/genética , Animais , Células Cultivadas , Citometria de Fluxo , Rejeição de Enxerto/genética , Rejeição de Enxerto/imunologia , Humanos , SuínosRESUMO
In the original publication, the fifth author name was erroneously published as "Patmika Jiaravuthiasan". The correct author name should read as, "Patmika Jiaravuthisan". The original article was corrected.
