Gene expression profile of human monocytes stimulated with all-trans retinoic acid (ATRA) or 1,25a-dihydroxyvitamin D3 (1,25D3)
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ABSTRACT: A role for vitamin A in host defense against Mycobacterium tuberculosis has been suggested through epidemiological and in vitro studies; however, the antimicrobial mechanism is unclear. Here, we demonstrate that vitamin A mediates host defense through regulation of cellular cholesterol content. Comparison of monocytes stimulated with all-trans retinoic acid (ATRA) or 1,25-dihydroxyvitamin D3, the biologically active forms of vitamin A and vitamin D respectively, indicates that ATRA and 1,25D3 induce mechanistically distinct antimicrobial activities. Gene expression profiling reveals that ATRA but not 1,25D3 triggers a lipid metabolism and efflux pathway, including expression of lysosomal lipid transport gene NPC2. ATRA-induced decrease in total cellular cholesterol content, subcellular lipid reorganization, lysosomal acidification and antimicrobial activity are all dependent upon expression of NPC2. Finally, the addition of HIV-protease inhibitors known to inhibit cholesterol efflux, Ritonavir and Nelfinavir, blocked both ATRA-induced cholesterol decrease as well as antimicrobial activity. Taken together, these results suggest that the vitamin A-mediated host defense mechanism against M. tuberculosis requires regulation of cellular cholesterol. Monocytes derived from four independent healthy blood donors that were stimulated with control (CTRL), ATRA or 1,25D3 at 10-8M for 18 hours.
Project description:A role for vitamin A in host defense against Mycobacterium tuberculosis has been suggested through epidemiological and in vitro studies; however, the antimicrobial mechanism is unclear. Here, we demonstrate that vitamin A mediates host defense through regulation of cellular cholesterol content. Comparison of monocytes stimulated with all-trans retinoic acid (ATRA) or 1,25-dihydroxyvitamin D3, the biologically active forms of vitamin A and vitamin D respectively, indicates that ATRA and 1,25D3 induce mechanistically distinct antimicrobial activities. Gene expression profiling reveals that ATRA but not 1,25D3 triggers a lipid metabolism and efflux pathway, including expression of lysosomal lipid transport gene NPC2. ATRA-induced decrease in total cellular cholesterol content, subcellular lipid reorganization, lysosomal acidification and antimicrobial activity are all dependent upon expression of NPC2. Finally, the addition of HIV-protease inhibitors known to inhibit cholesterol efflux, Ritonavir and Nelfinavir, blocked both ATRA-induced cholesterol decrease as well as antimicrobial activity. Taken together, these results suggest that the vitamin A-mediated host defense mechanism against M. tuberculosis requires regulation of cellular cholesterol.
Project description:Tuberculosis remains a major cause of death from an infectious disease worldwide, yet only 10% of people infected with Mycobacterium tuberculosis develop disease. Defining both necessary and sufficient immunologic determinants of protection remains a great scientific challenge. Analysis of peripheral blood gene expression profiles of active tuberculosis patients has identified correlates of risk for disease or pathogenesis. We sought to identify human potential candidate markers of host defense by studying gene expression profiles of macrophages, cells which, upon infection by M. tuberculosis, can mount an antimicrobial response. Weighted gene co-expression network analysis revealed an association between the cytokine, IL-32, and the vitamin D antimicrobial pathway in a network of IFN-γ and IL-15 induced ‘defense response’ genes. IL-32 was sufficient for induction of the vitamin D-dependent antimicrobial peptides, cathelicidin and DEFB4, and generation of antimicrobial activity in vitro, dependent on the presence of adequate 25-hydroxyvitamin D. The IL-15 induced ‘defense response’ macrophage gene network was integrated with ranked pairwise comparisons of gene expression from five different clinical data sets of latent vs. active tuberculosis or healthy controls, and a co-expression network derived from gene expression in patients with tuberculosis undergoing chemotherapy. Together, these analyses identified eight common genes, including IL-32, as molecular markers of latent tuberculosis and the IL-15 induced gene network. Inferring that maintaining M. tuberculosis in a latent state and preventing transition to active disease represents host resistance, we believe these results identify IL-32 as one functional marker and potential correlate of protection against active tuberculosis. Adherent peripheral blood monuclear cells were derived by Ficoll-Hypaque from the whole blood of four healthy donors. Cells adhered to tissue culture-treated plates for 2 h in 1% Fetal Bovine Serum (FBS) in RPMI. Cells were washed then stimulated with IL-10 (10ng/ml), IL-15 (10ng/ml) (R&D Systems), or IL-4 (1U/ml) in RPMI 1640 supplemented with 10% FBS at 37°C, 5% CO2. Cells were harvested at 6 h and 24 h after stimulation and monocytes purified by CD14 microbeads (Miltenyi Biotec) for a confirmed monocyte purity of at least 90%. RNA from purified monocytes extracted by Trizol and purified by Qiagen RNeasy Kit. RNA probe and microarray performed by UCLA Clinical Microarray Core using Ambion labeling kit and Affymetrix Human U133 Plus 2.0 array.
Project description:The immune mechanisms that control resistance vs. susceptibility to mycobacterial infection in humans were investigated by studying leprosy skin lesions, the site where the battle between the host and the pathogen is joined. Using an integrative genomics approach, we found an inverse correlation between of IFN-beta and IFN-gamma gene expression programs at the site of disease. The Type II IFN, IFN-gamma and its downstream vitamin D-dependent antimicrobial genes were preferentially expressed in the lesions from patients with the self-healing tuberculoid form of the disease and mediated antimicrobial activity against the pathogen, Mycobacterium leprae in vitro. In contrast, the Type I IFN, IFN-beta and its downstream genes, including IL-27 and IL-10, were induced in monocytes by M. leprae in vitro, and were preferentially expressed in the lesions of disseminated and progressive lepromatous form. The IFN-gamma induced macrophage antimicrobial response was inhibited by IFN-beta/IL-10, by a mechanism involving blocking the generation of bioactive 1,25-dihyroxy vitamin D as well as inhibiting induction of antimicrobial peptides cathelicidin and DEFB4. The ability of IFN-M-oM-^AM-" to inhibit the IFN-gamma induced vitamin D pathway including antimicrobial activity was reversed by neutralization of IL-10, suggesting a possible target for therapeutic intervention. Finally, a common IFN-beta and IL-10 gene signature was identified in both the skin lesions of leprosy patients and in the peripheral blood of active tuberculosis patients. Together these data suggest that the ability of IFN-beta to downregulate protective IFN-gamma responses provides one general mechanism by which some bacterial pathogens of humans evade protective host responses and contribute to pathogenesis. Peripheral blood monuclear cells derived through Ficoll-Hypaque from the blood of healthy human donors (n=4). Cells adhered to tissue culture treated 6-well plates for 2 hours in 1% Fetal Bovine Serum (FBS) RPMI and then stimulated by IL-10 (R&D Systems) 10ng/ml or media alone in 10% FBS RPMI for 24 hours at 37M-BM-0C, 5% CO2. After stimulation, cells harvested and monocytes isolated through CD14 positive selection (Miltenyi Biotec). RNA from purified monocytes extracted by Trizol and purified by Qiagen RNeasy Kit. RNA probe and microarray performed by UCLA Clinical Microarray Core using Ambion labeling kit and Affymetrix Human U133 Plus 2.0 array.
Project description:Effective innate immunity against many microbial pathogens requires macrophage programs that upregulate phagocytosis and direct antimicrobial pathways, two functions generally assumed to be coordinately regulated. Here the regulation of these key functions was investigated in human blood-derived macrophages. IL-10 induced the phagocytic pathway, including CD209 and scavenger receptors, resulting in phagocytosis of mycobacteria and oxLDL. IL-15 induced the vitamin D-dependent antimicrobial pathway and CD209, yet the cells were less phagocytic. The differential regulation of macrophage functional programs was confirmed by analysis of the spectrum of leprosy lesions: the macrophage phagocytosis pathway was prominent in the clinically progressive, multibacillary form, whereas the vitamin D-dependent antimicrobial pathway predominated in the self-limited form of the disease and in patients undergoing reversal reactions from the multibacillary to the self-limited form. These data indicate that macrophage programs for phagocytosis and antimicrobial responses are distinct and differentially regulated in innate immunity in bacterial infections. Experiment Overall Design: 7 LL lesions, 10 BT lesions, 7 RR lesions
Project description:Macrophages are a protective replicative niche for Mycobacterium tuberculosis (Mtb) but can kill the infecting bacterium when appropriately activated. To identify mechanisms of clearance, we compared bacterial restriction by human macrophages after treatment with 26 compounds, including some currently in clinical trials for tuberculosis. All-trans-retinoic acid (ATRA), an active metabolite of vitamin A, drove the greatest increase in Mtb control. Bacterial clearance was transcriptionally and functionally associated with changes in macrophage cholesterol trafficking and lipid metabolism. To determine how these macrophage changes affected bacterial control, we performed the first Mtb CRISPR interference screen in an infection model, identifying Mtb genes specifically required to survive in ATRA-activated macrophages. These data showed that ATRA treatment starves Mtb of cholesterol and the downstream metabolite propionyl-CoA. Supplementation with sources of propionyl-CoA, including cholesterol, abrogated the restrictive effect of ATRA. This work demonstrates that targeting the coupled metabolism of Mtb and the macrophage improves control of infection, and that it is possible to genetically map the mode of bacterial death using CRISPR interference.
Project description:In innate immune responses, activation of Toll-like receptors (TLRs) triggers direct antimicrobial activity against intracellular bacteria, which in murine, but not human, monocytes and macrophages is mediated principally by nitric oxide. We report here that TLR activation of human macrophages up-regulated expression of the vitamin D receptor and the vitamin D-1-hydroxylase genes, leading to induction of the antimicrobial peptide cathelicidin and killing of intracellular Mycobacterium tuberculosis. We also observed that sera from African-American individuals, known to have increased susceptibility to tuberculosis, had low 25-hydroxyvitamin D and were inefficient in supporting cathelicidin messenger RNA induction. These data support a link between TLRs and vitamin D-mediated innate immunity and suggest that differences in ability of human populations to produce vitamin D may contribute to susceptibility to microbial infection. Experiment Overall Design: The monocyte microarrays were generated using primary human monocytes stimulated with a TLR2/1L or media at 0, 3, 6, 12, 24 hour timepoints. A total of 10 donors were used with time 0 h samples prepared for each. For time points, we used cells from 4 of the 10 donors to prepare media and TLR2/1-stimulated samples. Experiment Overall Design: Dendritic cells were generated by culturing primary human monocytes with GM-CSF (800 U/ml) and IL-4 (1000 U/ml) for 7 days. The cells were then harvested and recultured for 12 hours with TLR2/1L or media. A total of four donors were used. Experiment Overall Design: See manuscript for specific details on data analysis and experimental design and reagents.
Project description:Niemann-Pick Type C (NPC) disease is a rare, genetic, lysosomal disorder with progressive neurodegeneration. Poor understanding of the pathophysiology and lack of blood-based diagnostic markers are major hurdles in the treatment and management of NPC and several additional neurological, lysosomal disorders. To identify disease severity correlates, we undertook whole genome expression profiling of sentinel organs, brain, liver, and spleen of Balb/c Npc1-/- mice (Npc1nih)relative to Npc1+/- at an asymptomatic stage, as well as early- and late-symptomatic stages. Unexpectedly, we found prominent up regulation of innate immunity genes with age-dependent change in their expression, in all three organs. We shortlisted a set of 12 secretory genes whose expression steadily increased with age in both brain and liver, as potential plasma correlates for the neurological disease. Ten were innate immune genes with eight ascribed to lysosomes. Several are known to be elevated in diseased organs of murine models of other lysosomal diseases including GaucherM-bM-^@M-^Ys disease, Sandhoff disease and MPSIIIB. We validated the top candidate lysozyme, in the plasma of Npc1-/- as well as Balb/c Npc1nmf164 mice (bearing a point mutation closer to human disease mutants) and show its reduction in response to an emerging therapeutic. We further established elevation of innate immunity in Npc1-/- mice through multiple functional assays including inhibition of bacterial infection as well as cellular analysis and immunohistochemistry. We used microarrays on the diseased organs, brain, liver and spleen of the Npc1-/- mice to unserstand the molecular changes occur during the progression of NPC diseases. From the data, we have identified 12 potential genes which can be potentially developed as blood-based biomarker. We have also discovered up regulation of innate iimunity genes in all three organs of Npc1-/- mice and functionally validated them in liver and spleen. Brain from 11 female Npc1M-bM-^HM-^R/M-bM-^HM-^R and 16 control female mice (Npc1+/+ and Npc1+/M-bM-^HM-^R) from 6 age groups (20-25, 37-40, 54-55, 59-62, 67-71 and 81-84 days) were surgically harvested. Liver and spleen from 6 Npc1-/- and 6 Npc1+/- female mice from three age group ( 20-25, 54-55 and 67-71 days) were surgically harvested. Organs were kept in RNA later and stored at -20 M-BM-0C until used. RNA was isolated and Affymetrix mouse 430 2.0 array hybridizations were performed by M-bM-^@M-^XUCLA Clinical Microarray CoreM-bM-^@M-^Y, UCLA, Los Angeles, CA, USA. Subsequent raw data were analyzed using DNA-Chip Analyzer (D-Chip) with the .CEL files obtained from AGCC. Data from Npc1-/- mice from all age groups were compared to control mice (Npc1+/- and/or Npc1-/- mice) from all age groups separately for brain, liver and spleen. 'Matrix Table1' corrsponds for brain, 'Matrix Table2' corresponds for liver and 'Matrix Table3' corresponds for spleen. Thresholds for selecting significant genes were set at a relative difference M-BM-31.5-fold, absolute difference M-BM-3100 signal intensity units and p<0.05. Genes that met all three criteria simultaneously were considered as significant change.
Project description:Calcium and 1,25-dihydroxyvitamin D3 (1,25D3), through the actions of their respective receptors, the Ca2+-sensing receptor (CaSR) and the vitamin D receptor (VDR), potentiate keratinocyte differentiation. VDR regulates epidermal keratinocyte proliferation and differentiation by modulating gene transcription, whereas the CaSR, a member of the family C G-protein coupled receptor, calcium mobilizes intracellular calcium and induces the formation of cell-cell junctions. 1,25D3 augments the sensitivity of the prodifferentiating actions of calcium by increasing the expression of CaSR. CaSR- and VDR-deficient keratinocytes share common characteristics such as abnormal intercellular adhesion and sphigolipid metabolism. Both CaSR and VDR are abundantly expressed in epidermal stem cell populations including CD34 expressing bulge keratinocytes in hair follicles and basal cells in interfollicular epidermis. To delineate the role of CaSR- and VDR-dependent pathways in regulating epidermal development and functions in physiological state, we generated conditional CaSR-null and VDR-null mice, where Casr and VDR gene was removed from keratinocytes. Keratinocyte-specific CaSR-null and VDR-null mice manifest distinct phenotypes. CaSR-null mice display defective epidermal permeability barrier function due to aberrant keratinocyte differentiation. VDR-null mice develop alopecia after completing the first hair follicle cycling. Concurrent ablation of CaSR and VDR genes in keratinocytes delays rate of wound repair and increases incidence of skin tumor formation to a greater extent than deletion of the CaSR or VDR alone, indicative of synergistic effects of calcium and 1,25D3 signaling. Gene expression profiles and subsequent pathway analysis on the epidermis derived from 5-day-old neonates revealed that ablation of CaSR or VDR increased expression of genes associated with cancer progression and metastasis. Deletion of VDR markedly inhibited signaling pathways that regulate hair development. Furthermore, concurrent ablation of CaSR and VDR significantly suppressed calcium, VDR, Wnt/b-catenin signaling, as well as epithelial adherence junction signaling to maintain appropriate keratinocyte adhesion. These results indicated the interplay of calcium/CaSR and 1,25D3/VDR signaling in keratinocyte proliferation and differentiation, and their importance in maintaining normal epidermal adhesion and functions. n=3 CON and KO (each sample contain RNA isolated from neonatal epidermis separated from 3 mice)
Project description:Calcium and 1,25-dihydroxyvitamin D3 (1,25D3), through the actions of their respective receptors, the Ca2+-sensing receptor (CaSR) and the vitamin D receptor (VDR), potentiate keratinocyte differentiation. VDR regulates epidermal keratinocyte proliferation and differentiation by modulating gene transcription, whereas the CaSR, a member of the family C G-protein coupled receptor, calcium mobilizes intracellular calcium and induces the formation of cell-cell junctions. 1,25D3 augments the sensitivity of the prodifferentiating actions of calcium by increasing the expression of CaSR. CaSR- and VDR-deficient keratinocytes share common characteristics such as abnormal intercellular adhesion and sphigolipid metabolism. Both CaSR and VDR are abundantly expressed in epidermal stem cell populations including CD34 expressing bulge keratinocytes in hair follicles and basal cells in interfollicular epidermis. To delineate the role of CaSR- and VDR-dependent pathways in regulating epidermal development and functions in physiological state, we generated conditional CaSR-null and VDR-null mice, where Casr and VDR gene was removed from keratinocytes. Keratinocyte-specific CaSR-null and VDR-null mice manifest distinct phenotypes. CaSR-null mice display defective epidermal permeability barrier function due to aberrant keratinocyte differentiation. VDR-null mice develop alopecia after completing the first hair follicle cycling. Concurrent ablation of CaSR and VDR genes in keratinocytes delays rate of wound repair and increases incidence of skin tumor formation to a greater extent than deletion of the CaSR or VDR alone, indicative of synergistic effects of calcium and 1,25D3 signaling. Gene expression profiles and subsequent pathway analysis on the epidermis derived from 5-day-old neonates revealed that ablation of CaSR or VDR increased expression of genes associated with cancer progression and metastasis. Deletion of VDR markedly inhibited signaling pathways that regulate hair development. Furthermore, concurrent ablation of CaSR and VDR significantly suppressed calcium, VDR, Wnt/b-catenin signaling, as well as epithelial adherence junction signaling to maintain appropriate keratinocyte adhesion. These results indicated the interplay of calcium/CaSR and 1,25D3/VDR signaling in keratinocyte proliferation and differentiation, and their importance in maintaining normal epidermal adhesion and functions. n=3 CON and KO (each sample contain RNA isolated from neonatal epidermis separated from 3 mice)
Project description:Calcium and 1,25-dihydroxyvitamin D3 (1,25D3), through the actions of their respective receptors, the Ca2+-sensing receptor (CaSR) and the vitamin D receptor (VDR), potentiate keratinocyte differentiation. VDR regulates epidermal keratinocyte proliferation and differentiation by modulating gene transcription, whereas the CaSR, a member of the family C G-protein coupled receptor, calcium mobilizes intracellular calcium and induces the formation of cell-cell junctions. 1,25D3 augments the sensitivity of the prodifferentiating actions of calcium by increasing the expression of CaSR. CaSR- and VDR-deficient keratinocytes share common characteristics such as abnormal intercellular adhesion and sphigolipid metabolism. Both CaSR and VDR are abundantly expressed in epidermal stem cell populations including CD34 expressing bulge keratinocytes in hair follicles and basal cells in interfollicular epidermis. To delineate the role of CaSR- and VDR-dependent pathways in regulating epidermal development and functions in physiological state, we generated conditional CaSR-null and VDR-null mice, where Casr and VDR gene was removed from keratinocytes. Keratinocyte-specific CaSR-null and VDR-null mice manifest distinct phenotypes. CaSR-null mice display defective epidermal permeability barrier function due to aberrant keratinocyte differentiation. VDR-null mice develop alopecia after completing the first hair follicle cycling. Concurrent ablation of CaSR and VDR genes in keratinocytes delays rate of wound repair and increases incidence of skin tumor formation to a greater extent than deletion of the CaSR or VDR alone, indicative of synergistic effects of calcium and 1,25D3 signaling. Gene expression profiles and subsequent pathway analysis on the epidermis derived from 5-day-old neonates revealed that ablation of CaSR or VDR increased expression of genes associated with cancer progression and metastasis. Deletion of VDR markedly inhibited signaling pathways that regulate hair development. Furthermore, concurrent ablation of CaSR and VDR significantly suppressed calcium, VDR, Wnt/b-catenin signaling, as well as epithelial adherence junction signaling to maintain appropriate keratinocyte adhesion. These results indicated the interplay of calcium/CaSR and 1,25D3/VDR signaling in keratinocyte proliferation and differentiation, and their importance in maintaining normal epidermal adhesion and functions. n=3 CON and DKO (each sample contain RNA isolated from neonatal epidermis separated from 3 mice)