Project description:Monocyte maturation plays an important role in many physiological and patological processes includning cancer. Complement factor H is a complemnt inhibitor but has been shown to also have various cellular functions. We used microarrays to detail the global programme of gene expression underlying maturationn of monocytes upon FH stimulation and identified distinct classes of up-regulated genes during this process.
Project description:Tumor cells modulate host immunity by secreting extracellular vesicles (EV) and soluble factors in circulation. Their interactions with myeloid cells could lead to the generation of myeloid-derived suppressor cells (MDSC), which strongly inhibit the anti-tumor function of T and NK cells. We demonstrated previously that EV derived from mouse and human melanoma cells induced such immunosuppressive activity via upregulating the expression of programmed cell death ligand 1 (PD-L1) on myeloid cells that was dependent on the heat-shock protein 90a (HSP90a) in EV and on the toll-like receptor (TLR) on myeloid cells. Here, we investigated whether soluble HSP90α could convert monocytes into immunosuppressive MDSC. CD14+ monocytes were isolated from the peripheral blood of healthy donors, incubated with human rHSP90α alone or in the presence of inhibitors of TLR4 signaling and analyzed by flow cytometry. Inhibition of T cell proliferation assay was applied to assess immunosuppressive function of rHSP90α-treated monocytes. The concentration of HSP90α was measured by ELISA in plasma of advanced melanoma patients and correlated with clinical outcome. We found that the incubation of monocytes with rHSP90α for 16 h resulted in a strong upregulation of PD-L1 expression, whereas ROS and NO production as well as the expression of arginase-1, adenosine producing ectoenzymes CD39 and CD73 remained unchanged. The PD-L1 upregulation can be blocked by anti-TLR4 antibodies and an NF-κB inhibitor. After longer incubation (for 24h), rHSP90α-treated monocytes downregulated HLA-DR expression and acquired an augmented viability and resistance to apoptosis. Moreover, these monocytes were converted into MDSC indicated by their capacity to inhibit T cell proliferation mediated by TLR4 signaling as well as PD-L1 and indolamin-2,3-Dioxygenase (IDO) 1 expression. Higher levels of HSP90α in plasma of melanoma patients correlated with augmented PD-L1 expression on circulating monocytic (M) MDSC. Furthermore, melanoma patients with high levels of HSP90α displayed shorter progression-free survival (PSF) upon the treatment with immune checkpoint inhibitors (ICI).
Project description:Purpose: The complement system is closely linked to the pathogenesis of age-related macular degeneration (AMD). Several complement genes are expressed in retinal pigment epithelium (RPE), and complement proteins accumulate in drusen. Further, a common variant of complement factor H (CFH) confers increased risk of developing AMD. Because the mechanisms by which changes in the function of CFH influence development of AMD are unclear, we examined ocular complement expression as a consequence of age in control and CFH null mutant mice. Methods: Gene expression in neuroretinas and RPE/choroid from young and aged WT and Cfh-/- C57BL/6J mice was analysed by microarrays. Expression of a wide range of complement genes was compared to expression in splenocytes and in liver tissue by qRT-PCR. Results: An age-associated increased expression of complement, particularly C1q, C3 and Factor B, in the RPE/choroid coincided with increased expression of the negative regulators Cfh and Cd59a in the neuroretina. Young mice deficient in CFH expressed Cd59a similar to WT, but failed to upregulate Cd59a expression with age. Both hepatic and splenic expression of Cd59a increased with age regardless of Cfh genotype. Conclusions: While the connection between CFH deficiency and failure to up-regulate CD59a remains unknown, these results suggest that expression of CD59 is tissue-specific and that neuroretinal regulation depends on CFH. This could contribute to the visual functional deficits and morphological changes in the Cfh-/- mouse retina that occur with age, and further suggests that deficient neuroretinal regulation of complement could represent an early event in AMD. Gene expression in neuroretinas and RPE/choroid from young and aged WT and Cfh-/- mice, 4 biological replicates in each group.
Project description:Purpose: The complement system is closely linked to the pathogenesis of age-related macular degeneration (AMD). Several complement genes are expressed in retinal pigment epithelium (RPE), and complement proteins accumulate in drusen. Further, a common variant of complement factor H (CFH) confers increased risk of developing AMD. Because the mechanisms by which changes in the function of CFH influence development of AMD are unclear, we examined ocular complement expression as a consequence of age in control and CFH null mutant mice. Methods: Gene expression in neuroretinas and RPE/choroid from young and aged WT and Cfh-/- C57BL/6J mice was analysed by microarrays. Expression of a wide range of complement genes was compared to expression in splenocytes and in liver tissue by qRT-PCR. Results: An age-associated increased expression of complement, particularly C1q, C3 and Factor B, in the RPE/choroid coincided with increased expression of the negative regulators Cfh and Cd59a in the neuroretina. Young mice deficient in CFH expressed Cd59a similar to WT, but failed to upregulate Cd59a expression with age. Both hepatic and splenic expression of Cd59a increased with age regardless of Cfh genotype. Conclusions: While the connection between CFH deficiency and failure to up-regulate CD59a remains unknown, these results suggest that expression of CD59 is tissue-specific and that neuroretinal regulation depends on CFH. This could contribute to the visual functional deficits and morphological changes in the Cfh-/- mouse retina that occur with age, and further suggests that deficient neuroretinal regulation of complement could represent an early event in AMD.
Project description:Caspases, which are key effectors of apoptosis, have demonstrated non-apoptotic functions. One of these functions is the differentiation into macrophages of peripheral blood monocytes exposed to Colony-Stimulating Factor-1 (CSF1). Conversely, GM-CSF induces the differentiation of monocytes into macrophages in a caspase-independent manner. Macrophages generated by CSF1 and GM-CSF have distinct polarity. Macrophage polarization plays an important role in the pathogenesis of diverse human diseases as cancer, leading us to explore if caspase inhibition would affect macrophage polarization. To explore the role of caspases in CSF1 differentiation, we used human monocytes sorted from buffy coats treated by cytokines. We reported that caspase inhibition delays the ex vivo differentiation of peripheral blood monocytes exposed to CSF1 and modifies the phenotype of generated macrophages, e.g. cell shape, surface markers. Moreover, by RNAseq, we observed that the macrophages generated in presence of CSF1 and QVD are different from CSF1-treated monocytes and from GM-CSF-treated monocytes. Cell cycle and focal adhesion-related pathway genes were selectively down-regulated. This study confirms the importance of caspase activation in CSF1 differentiation.
Project description:Caspases, which are key effectors of apoptosis, have demonstrated non-apoptotic functions. One of these functions is the differentiation into macrophages of peripheral blood monocytes exposed to Colony-Stimulating Factor-1 (CSF1). Macrophage polarization plays an important role in the pathogenesis of diverse human diseases as cancer, leading us to explore if caspase inhibition would affect macrophage polarization. To explore the role of caspases in CSF1 differentiation, we used human monocytes sorted from buffy coats treated by cytokines. We reported that caspase inhibition delays the ex vivo differentiation of peripheral blood monocytes exposed to CSF1 and modifies the phenotype of generated macrophages, e.g. cell shape, surface markers. Moreover, by RNAseq, we observed that the macrophages generated in presence of CSF1 and QVD are different from CSF1-treated monocytes. This study confirms the importance of caspase activation in CSF1 differentiation.