Therapeutic Delivery of CCL2 Modulates Immune Response and Restores Host-microbe Homeostasis
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ABSTRACT: The oral cavity is an easily accessible environment that allows for protective interventions aiming at modulating the immune response to control disease processes driven by a breakdown of host- microbe homeostasis. Periodontal disease (PD) is a prevalent condition in which quantitative and qualitative changes of the oral microbiota (dysbiosis) trigger non-resolving chronic inflammation, progressive bone loss and ultimately tooth loss. Here, we demonstrate the therapeutic benefit of local sustained delivery of the myeloid-recruiting chemokine CCL2 in murine ligature-induced PD using clinically relevant models as a preventive, interventional or reparative therapy. Local delivery of CCL2 into the periodontium inhibited bone loss and accelerated bone gain that could be ascribed to reduced osteoclasts numbers. CCL2 treatment upregulated M2-macrophage and downregulated pro-inflammatory and pro-osteoclastic markers. Furthermore, single cell RNA sequencing indicated that CCL2 therapy reversed disease-associated transcriptomic profiles of murine gingival macrophages via inhibiting TREM-1 signaling in classically activated macrophages and inducing PKA signaling in infiltrating macrophages. Finally, 16S rRNA sequencing showed mitigation of microbial dysbiosis in the periodontium that correlated with a reduction in microbial load in CCL2- treated mice. This study reveals a novel protective effect of CCL2 local delivery in PD as a model for chronic inflammatory diseases caused by a disturbance in host-microbe homeostasis.
Project description:Mice with either a cranial bone defect, skin biopsy punch injury, quadriceps volumetric muscle loss defect or myocardial infarction (MI) were treated with Tregs, either via local hydrogel-mediated delivery (for bone, muscle and skin), or with systemic (intravenous) delivery (for heart). Control mice were treated with hydrogel alone (for bone, muscle and skin) or PBS (for heart). On day 4 and 7 post-MI, the injured tissues were harvested and the endogenous monocytes/macrophages were sorted and used for mini-bulk RNA sequencing, to compare the transcriptomic profiles of injured tissue monocytes/macrophages in Treg-treated and untreated mice post-injury.
Project description:Morphine causes microbial dysbiosis. In this study we focused on restoration of native microbiota in morphine treated mice and looked at the extent of restoration and immunological consequences of this restoration. Fecal transplant has been successfully used clinically, especially for treating C. difficile infection2528. With our expanding knowledge of the central role of microbiome in maintenance of host immune homeostasis17, fecal transplant is gaining importance as a therapy for indications resulting from microbial dysbiosis. There is a major difference between fecal transplant being used for the treatment of C. difficile infection and the conditions described in our studies. The former strategy is based on the argument that microbial dysbiosis caused by disproportionate overgrowth of a pathobiont can be out-competed by re-introducing the missing flora by way of a normal microbiome transplant. This strategy is independent of host factors and systemic effects on the microbial composition. Here, we show that microbial dysbiosis caused due to morphine can be reversed by transplantation of microbiota from the placebo-treated animals.
Project description:Fibroblasts that reside in the gut mucosa are among the key regulators of innate immune cells, but their role in the regulation of the defense functions of macrophages remains unknown. MyD88 is suggested to shape fibroblast responses in the intestinal microenvironment. We found that mice lacking MyD88 in fibroblasts showed a decrease in the colonic antimicrobial defense, developing dysbiosis and aggravated DSS-induced colitis. These pathological changes were associated with accumulation of Arginase 1+ macrophages with low antimicrobial defense capability. Mechanistically, production of IL-6 and CCL2 downstream of MyD88 was critically involved in fibroblast-mediated support of macrophage antimicrobial function, and IL-6/CCL2 neutralization resulted in the generation of macrophages with decreased production of antimicrobial peptide cathelicidin and impaired bacterial clearance. Collectively, these findings revealed a critical role of fibroblast-intrinsic MyD88 signaling in regulating macrophage antimicrobial defense under colonic homeostasis, and its disruption results in dysbiosis, predisposing host to the development of intestinal inflammation.
Project description:Fibroblasts that reside in the gut mucosa are among the key regulators of innate immune cells, but their role in the regulation of the defense functions of macrophages remains unknown. MyD88 is suggested to shape fibroblast responses in the intestinal microenvironment. We found that mice lacking MyD88 in fibroblasts showed a decrease in the colonic antimicrobial defense, developing dysbiosis and aggravated DSS-induced colitis. These pathological changes were associated with accumulation of Arginase 1+ macrophages with low antimicrobial defense capability. Mechanistically, production of IL-6 and CCL2 downstream of MyD88 was critically involved in fibroblast-mediated support of macrophage antimicrobial function, and IL-6/CCL2 neutralization resulted in the generation of macrophages with decreased production of antimicrobial peptide cathelicidin and impaired bacterial clearance. Collectively, these findings revealed a critical role of fibroblast-intrinsic MyD88 signaling in regulating macrophage antimicrobial defense under colonic homeostasis, and its disruption results in dysbiosis, predisposing host to the development of intestinal inflammation.
Project description:Fibroblasts that reside in the gut mucosa are among the key regulators of innate immune cells, but their role in the regulation of the defense functions of macrophages remains unknown. MyD88 is suggested to shape fibroblast responses in the intestinal microenvironment. We found that mice lacking MyD88 in fibroblasts showed a decrease in the colonic antimicrobial defense, developing dysbiosis and aggravated DSS-induced colitis. These pathological changes were associated with accumulation of Arginase 1+ macrophages with low antimicrobial defense capability. Mechanistically, production of IL-6 and CCL2 downstream of MyD88 was critically involved in fibroblast-mediated support of macrophage antimicrobial function, and IL-6/CCL2 neutralization resulted in the generation of macrophages with decreased production of antimicrobial peptide cathelicidin and impaired bacterial clearance. Collectively, these findings revealed a critical role of fibroblast-intrinsic MyD88 signaling in regulating macrophage antimicrobial defense under colonic homeostasis, and its disruption results in dysbiosis, predisposing host to the development of intestinal inflammation.
Project description:Fibroblasts that reside in the gut mucosa are among the key regulators of innate immune cells, but their role in the regulation of the defense functions of macrophages remains unknown. MyD88 is suggested to shape fibroblast responses in the intestinal microenvironment. We found that mice lacking MyD88 in fibroblasts showed a decrease in the colonic antimicrobial defense, developing dysbiosis and aggravated DSS-induced colitis. These pathological changes were associated with accumulation of Arginase 1+ macrophages with low antimicrobial defense capability. Mechanistically, production of IL-6 and CCL2 downstream of MyD88 was critically involved in fibroblast-mediated support of macrophage antimicrobial function, and IL-6/CCL2 neutralization resulted in the generation of macrophages with decreased production of antimicrobial peptide cathelicidin and impaired bacterial clearance. Collectively, these findings revealed a critical role of fibroblast-intrinsic MyD88 signaling in regulating macrophage antimicrobial defense under colonic homeostasis, and its disruption results in dysbiosis, predisposing host to the development of intestinal inflammation.
2025-03-05 | GSE291179 | GEO
Project description:Therapeutic Delivery of CCL2 Modulates Immune Response and Restores Host-microbe Homeostasis
Project description:Microbiota dysbiosis and mucosa-associated bacteria are involved in colorectal cancer progression. We hypothesized that a time-specific interaction between dysbiotic pathobionts and host responses promote tumor growth. This study aimed to elucidate the dysfunctional host-microbe interplay in colon tumorigenesis by using a time-series metagenomics approach. A transient surge in fecal microbial richness was linked to a unique transcriptome profile in the mouse colon during carcinoma transformation. Monitoring gut microbiome may help identifying the window-of-opportunity to induce tumor regression using bacteria-targeted precision medicine.
Project description:Microbiota dysbiosis and mucosa-associated bacteria are involved in colorectal cancer progression. We hypothesized that a time-specific interaction between dysbiotic pathobionts and host responses promote tumor growth. This study aimed to elucidate the dysfunctional host-microbe interplay in colon tumorigenesis by using a time-series metagenomics approach. A transient surge in fecal microbial richness was linked to a unique transcriptome profile in the mouse colon during carcinoma transformation. Monitoring gut microbiome may help identifying the window-of-opportunity to induce tumor regression using bacteria-targeted precision medicine.