RESUMO
Mucormycosis has a high mortality and is increasingly diagnosed in hematopoietic stem cell transplant (HSCT) recipients. In this setting, there is a growing interest to restore host defense to combat infections by adoptively transferring donor-derived immunocompetent cells. Natural killer (NK) cells exhibit antitumor and antiinfective activity, but the interaction with Mucormycetes is unknown. Our data demonstrate that both unstimulated and IL-2 prestimulated human NK cells damage Rhizopus oryzae hyphae, but do not affect resting conidia. The damage of the fungus is mediated, at least in part, by perforin. R. oryzae hyphae decrease the secretion of immunoregulatory molecules by NK cells, such as IFN-γ and RANTES, indicating an immunosuppressive effect of the fungus. Our data indicate that NK cells exhibit activity against Mucormycetes and future research should evaluate NK cells as a potential tool for adoptive immunotherapy in HSCT.
Assuntos
Hifas/fisiologia , Imunidade Celular , Células Matadoras Naturais/imunologia , Rhizopus/fisiologia , Esporos Fúngicos/fisiologia , Degranulação Celular/imunologia , Células Cultivadas , Quimiocina CCL5/genética , Quimiocina CCL5/imunologia , Expressão Gênica , Fator Estimulador de Colônias de Granulócitos e Macrófagos/genética , Fator Estimulador de Colônias de Granulócitos e Macrófagos/imunologia , Interações Hospedeiro-Patógeno , Humanos , Interferon gama/genética , Interferon gama/imunologia , Interleucina-2/farmacologia , Células Matadoras Naturais/efeitos dos fármacos , Células Matadoras Naturais/microbiologia , Perforina/genética , Perforina/imunologiaRESUMO
Because natural killer (NK) cells kill tumor cells and combat infections, there is growing interest in adoptively transferring NK cells to hematopoietic stem cell recipients. Unfortunately, in humans, the activity of NK cells against Aspergillus species, the major cause of invasive fungal infection in stem cell recipients, are poorly characterized. Our results show that unstimulated and interleukin-2 prestimulated human NK cells kill Aspergillus fumigatus hyphae but do not affect resting conidia. Killing is also induced by the supernatant of prestimulated NK cells and human perforin. The high levels of interferon-γ and granulocyte macrophage colony-stimulating factor produced by prestimulated NK cells are significantly reduced by Aspergillus, indicating an immunosuppressive effect of the fungus. Whereas Aspergillus hyphae activate NK cells, resting, and germinating, conidia and conidia of ΔrodA mutants lacking the hydrophobic surface layer do not. Our results suggest that adoptively transferred human NK cells may be a potential antifungal tool in the transplantation context.
Assuntos
Aspergillus fumigatus/fisiologia , Hifas/fisiologia , Células Matadoras Naturais/fisiologia , Esporos Fúngicos/fisiologia , Aspergillus fumigatus/imunologia , Células Cultivadas , Quimiocina CCL5/genética , Quimiocina CCL5/metabolismo , Regulação da Expressão Gênica , Fator Estimulador de Colônias de Granulócitos e Macrófagos/genética , Fator Estimulador de Colônias de Granulócitos e Macrófagos/metabolismo , Humanos , Hifas/imunologia , Interferon gama/genética , Interferon gama/metabolismo , Interleucina-2/genética , Interleucina-2/metabolismo , Esporos Fúngicos/imunologiaRESUMO
Invasive aspergillosis remains a serious complication in patients undergoing allogeneic stem cell transplantation (SCT). Since it became clear that lymphocytes provide a critical secondary defense against fungi, adoptive transfer of functionally active anti-Aspergillus T cells might be an option to restore adaptive immune effector mechanisms. Using the interferon (IFN)-gamma secretion assay, we isolated human activated T cells upon stimulation with a cellular extract of Aspergillus fumigatus. Culturing this cell population for 14 days, we obtained an average of 1.1 x 10(7) cells from a single 100-mL blood draw in 7 of 7 healthy individuals. Within another 14 days, these cells were expanded to an average number of 2.0 x 10(8) T-helper 1 (T(H)1) cells secreting IFN-gamma on stimulation with Aspergillus antigens. Testing various fungal antigen extracts, similar proportions of IFN-gamma-producing CD3+/CD4+ cells were obtained upon activation with antigen extracts of A. fumigatus, A. flavus, A. niger, and Penicillium chrysogenum, whereas no significant IFN-gamma production was observed upon activation with antigen extracts of Alternaria alternata and Candida albicans. In addition, generated T cells were able to induce damage to A. fumigatus hyphae, and significantly increased hyphal damage induced by human neutrophils. CD4+ T-cell-mediated alloreactivity of generated anti-Aspergillus T cells was clearly reduced compared with that of the original cell population. In conclusion, we present a simple and feasible strategy for rapid generation of a high number of functional active T cells against Aspergillus from a single blood draw. Our data suggest that functionally active T cells against Aspergillus could be a promising treatment option for patients undergoing allogeneic SCT.
