Project description:HIV-1 persists in cellular reservoirs despite effective antiretroviral therapy (ART). CD4+ T cells are the well-known reservoir, but there is growing evidence that myeloid cells, including circulating monocytes, are also a clinically relevant reservoir. However, it is unclear what are preferentially infected monocyte subsets in vivo. Here, we show that a monocyte fraction expressing the stem cell marker CD34 is more susceptible to HIV-1 infection than the CD34-negative major subset. In ART-untreated viremic patients, CD34+ fraction increased in the percentage in total monocytes, and harbored more proviral DNA than the major subset. Consistent with this, when compared to the major subset, CD34+ fraction expressed HIV-1 receptors (CD4 and CCR5) at higher levels and HIV-1 restriction factors (MX2 and SAMHD1) at lower levels. Interestingly, proviral DNA was detected in CD34+ fraction of ART-treated virologically suppressed patients. CD34+ monocytes were also present in lymph nodes, and expressed CD4 and CCR5 at higher levels than the major subset, as observed for peripheral blood. Moreover, CD34+ monocytes present in peripheral blood and lymph nodes highly expressed CCR7 and sphingosine-1-phosphate receptor 1 (S1PR1), critical regulators of in vivo cellular trafficking. Our findings suggest that circulating CD34+ monocytes are infected with residual HIV-1 after migrating into tissues including lymph nodes and return to circulation, which explains the detection of proviral DNA in the cells even after long-term ART.
Project description:Monocytes are a heterogeneous cell population with subset-specific functions and phenotypes. The differential expression of CD14 and CD16 distinguishes classical CD14++CD16-, intermediate CD14++CD16+ and non-classical CD14+CD16++ monocytes. However, CD14++CD16+ monocytes remain the most poorly characterized subset so far. Therefore we analyzed the transcriptomes of the three monocyte subsets using SuperSAGE in combination with high-throughput sequencing. Analysis of 5,487,603 tags revealed unique identifiers of CD14++CD16+ monocytes, delineating these cells from the two other monocyte subsets. CD14++CD16+ monocytes were linked to antigen processing and presentation (e.g. CD74, HLA-DR, IFI30, CTSB), to inflammation and monocyte activation (e.g. TGFB1, AIF1, PTPN6), and to angiogenesis (e.g. TIE2, CD105). Therefore we provide genetic evidence for a distinct role of CD14++CD16+ monocytes in human immunity. Human monocyte subsets (CD14++CD16-, CD14++CD16+, CD14+CD16++) were isolated from 12 healthy volunteers based on MACS technology. Total RNA from monocyte subsets was isolated and same aliquots from each donor and monocyte subset were matched for SuperSAGE. Three SuperSAGE libraries (CD14++CD16-, CD14++CD16+ and CD14+CD16++) were generated.
Project description:This SuperSeries is composed of the following subset Series: GSE14278: Comparison of CD4+ T cell function between HIV-1 resistant and HIV-1 susceptible individuals (Affymetrix) GSE14279: Comparison of CD4+ T cell function between HIV-1 resistant and HIV-1 susceptible individuals (Immune) Refer to individual Series
Project description:Monocytes are a heterogeneous cell population with subset-specific functions and phenotypes. The differential expression of CD14 and CD16 distinguishes classical CD14++CD16-, intermediate CD14++CD16+ and non-classical CD14+CD16++ monocytes. However, CD14++CD16+ monocytes remain the most poorly characterized subset so far. Therefore we analyzed the transcriptomes of the three monocyte subsets using SuperSAGE in combination with high-throughput sequencing. Analysis of 5,487,603 tags revealed unique identifiers of CD14++CD16+ monocytes, delineating these cells from the two other monocyte subsets. CD14++CD16+ monocytes were linked to antigen processing and presentation (e.g. CD74, HLA-DR, IFI30, CTSB), to inflammation and monocyte activation (e.g. TGFB1, AIF1, PTPN6), and to angiogenesis (e.g. TIE2, CD105). Therefore we provide genetic evidence for a distinct role of CD14++CD16+ monocytes in human immunity.
Project description:Global gene expressions of human cord blood-derived 18Lineage-negative (18Lin-)CD34+CD38-CD133+GPI-80+ cells (CD34+ HSCs), 18Lin-CD34-CD133+GPI-80+ cells (CD34- HSCs) and 18Lin-CD34+CD133- cells (non-HSCs) were analyzed. Results provide an insight into the molecular mechanisms underlying the self-renewal, maintenance and differentiation of human cord blood-derived CD34+/- HSCs.
Project description:The label-free quantitative proteome was generated for 42 primary AML patient samples enriched for CD34+ cells (or mononuclear cells in the case of NPMcyt sameples) and as controls 6 mobilized peripheral blood CD34+ cells were included. Furthermore, 6 AML cell lines were included, and also primary mesenchymal stem cells grown under normaoxia or hypoxia were included.
Project description:Although a considerable number of reports indicate an involvement of the Hox-A10 gene in the molecular control of hematopoiesis, the conclusions of such studies are quite controversial since they support, in some cases, a role in the stimulation of stem cell self-renewal and myeloid progenitor expansion while, in others, implicate this transcription factor in the induction of monocyte - macrophage differentiation. To clarify this issue we analyzed the biological effects and the transcriptome changes determined in human primary CD34+ hematopoietic progenitors by retroviral transduction of a full length Hox-A10 cDNA. The results obtained clearly indicated that this homeogene is an inducer of monocyte differentiation, at least partly acting through the up-regulation of MafB gene, recently identified as master regulator of such maturation pathway. By using a combined approach based on computational analysis, EMSA experiments and luciferase assays, we were able to demonstrate the presence of a Hox-A10 binding site in the promoter region of the MafB gene, which suggested the likely molecular mechanism underlying the observed effect. Interestingly, stimulation of the same cells with the Vitamin D3 monocyte differentiation inducer resulted in a clear increase of Hox-A10 and MafB transcripts, indicating the existence of a precise transactivation cascade involving VDR, Hox-A10 and MafB transcription factors. Altogether these data allow to conclude that the Vitamin D3 / Hox-A10 pathway supports MafB function during the induction of monocyte differentiation. Experiment Overall Design: RNA pools (100 ng) of LXIDN and LHoxA10IDN transduced CD34+ cells, obtained from three independent experiments, were converted in labelled cRNA according with the âTwo cycleâ protocol advised by Affymetrix. cRNA has been used to hybridise Affymetrix HG-U133A GeneChip arrays. Images obtained by scanning chips of LXIDN and LHoxA10IDN transduced CD34+ cells were processed using the GeneChip Operating Software. Microarray analysis of Hox-A10 transduced CD34+ cells provided a substantial contribute for a better comprehension of the biological effects driven by this transcription factor in human primary hematopoietic stem / progenitor cells. Results of this analysis confirmed the stimulatory effect exerted by Hox-A10 on monocytopoiesis, disclosing an up-regulated expression of transcription factors and differentiation markers (CD antigens, granule proteins, cytokines / chemokines) that are typically associated with this maturation lineage. In addition, they also evidenced a decreased expression of genes related to erythroid and granulocyte differentiation programs. This last effect was also confirmed by cytochemical and morphological evaluation of Hox-A10 transduced CD34+ cells.
Project description:Human monocytes can be classified into two subsets with distinctive characteristics. In this study, we report a difference in apoptotic potential between these two subsets with CD14(+/low)CD16(+) monocytes being more susceptible than CD14(+)CD16(-) monocytes to undergo spontaneous apoptosis and apoptosis induced by reactive oxygen species (ROS). By global transcriptomic and proteomic approaches, we observed that CD14(+/low)CD16(+) monocytes expressed higher levels of pro-apoptotic genes and proteins such as TNF?, caspase 3, Bax and cytochrome c and showed more caspases 3 and 7 activities. They also exhibited greater aerobic respiration resulting in a higher production of ROS from the mitochondria. CD14(+)CD16(-) monocytes, in contrast, showed higher expression of glutathione (GSH)-metabolizing genes such as GSH peroxidase and microsomal GSH S-transferase and were more resistant to oxidative stress than CD14(+/low)CD16(+) monocytes. The apoptosis of CD14(+/low)CD16(+) monocytes was ROS dependent as reducing ROS levels significantly reduced cell death. This is the first report of a differential apoptotic propensity of human monocyte subsets, and gaining a better understanding of this process may help to provide a better understanding of the roles of these subsets during homeostasis and under pathological conditions, particularly in situations in which high levels of oxidants are present.