Corneal tissue induces transcription of metallothioneins in monocyte-derived human macrophages

ABSTRACT: Purpose Immune reactions following corneal transplantation are the most common cause of transplant failure. However, the underlying mechanisms of corneal graft rejection are not yet fully understood but increasing evidence points to a crucial role of the innate immune system in this context. Using a human in vitro model, we aimed to assess the response of human macrophages to stimulation with human corneal tissue and whether corneal endothelial cells (CEC) have immune-modulating properties. Methods Human monocytes were isolated from peripheral blood mononuclear cells (PBMC) and differentiated into monocyte-derived macrophages (MDM). A standardized protocol was used for disintegration of human corneas into fragments of defined sizes. MDMs were stimulated using processed corneal material with or without CEC. Lipopolysaccharide (LPS) or interferon-gamma (IFNγ) served as controls. RNA sequencing was applied to analyze the impact of differential stimulation of MDMs on their transcriptional profile. Results The transcriptional profile of MDMs was significantly modulated by the type of stimulus used for MDM activation as well as by the individual donor. LPS- or IFNγ-stimulation resulted in distinct transcriptional alterations compared to unstimulated MDMs including an upregulation of various cytokines such as CXCL9 and CCL3, 4, 5 and 19. Corneal tissue induced the differential expression of 45 genes when compared to unstimulated MDMs, with several metallothioneins (MTs) among the upregulated factors (MT1A, MT1E, MT1F, MT1G, MT1H, MT1L, MT1M, MT1X, MT2A). This effect was independent of the presence or absence of CEC. Conclusions The MDM in vitro model proved to be a robust tool to study the effects of LPS, IFNγ and corneal tissue homogenates on the transcriptional activity of MDM. Human macrophages showed a distinct upregulation of various MTs when challenged with human corneal allogen with or without corneal endothelium, which might have an immune-modulatory effect. As a general observation, it appears that in MDM-based studies a significant donor-dependent effect on the transcriptional profile of MDMs needs to be considered and adjusted before downstream analysis.

ORGANISM(S): Homo sapiens

PROVIDER: GSE148703 | GEO | 2020/12/21

REPOSITORIES: GEO