Project description:A number of inhibitors of chemokine CCL2 and its receptor CCR2 are in development and may find application for treating a range of inflammatory conditions, including autoimmune and viral arthritides. Herein we sought to determine the effect of CCR2 deficiency on arthritis caused by an arthritogenic alphavirus, Chikungunya virus. Chikungunya virus (LR2006-OPY1) was injected subcutaneously into the hind foot of either CCR2 knockout or wild-type control mice (n=4-6). At day 0 and d7 post infection, RNA from the feet was harvested, the RNA was pooled (4-6 feet per time point per mouse strain) and gene expression analysis was performed using Mouse Gene ST arrays (Affymetrix).
Project description:A number of inhibitors of chemokine CCL2 and its receptor CCR2 are in development and may find application for treating a range of inflammatory conditions, including autoimmune and viral arthritides. Herein we sought to determine the effect of CCR2 deficiency on arthritis caused by an arthritogenic alphavirus, Chikungunya virus.
Project description:Arthritogenic alphaviruses, including chikungunya virus (CHIKV), Mayaro virus and Ross River virus, cause long-lasting musculoskeletal pain and inflammation. However, the mechanisms driving chronic disease remain unclear. Here, we used single-cell RNA sequencing, spatial transcriptomics and flow cytometry to investigate joint-associated tissues in alphavirus-infected mice at a late stage of infection. We identified an accumulation of inflammatory macrophages in joint-associated tissues with elevated expression of inflammatory markers. These cells harbour CHIKV RNA, suggesting ongoing viral replication during chronic disease. We also identified an accumulation of CD4+ T cells in these tissues expressing Ifng, and found that depletion of CD4+ T cells diminished major histocompatibility complex class II expression on joint macrophages, highlighting their potential role in inflammation. Treatment with a small molecule inhibitor of CHIKV replication during chronic disease reduced viral RNA and joint inflammation. Our data suggest that macrophages harbour replicating viral RNA and contribute to the sustained joint inflammation associated with chronic alphavirus disease.
Project description:Although oral antibiotics can predispose to joint inflammation, this phenomenon remains poorly understood. Here, we leverage mouse models of alphavirus arthritis to investigate the gut commensals, metabolites, and host mechanisms that promote musculoskeletal inflammation. Mice treated with a short course of oral antibiotics exhibited worsened arthritis after chikungunya virus (CHIKV) infection. This phenotype was associated with loss of short chain fatty acids (SCFA) and greater intestinal permeability, and required TLR4 signaling, MyD88 expression, monocytes, antigen-specific and bystander CD4+ T cells, and pro-inflammatory cytokines. Administration of exogenous SCFA or colonization of mice with bacterial species that generate SCFA mitigated CHIKV-induced joint inflammation. Single cell RNA sequencing revealed that gut-derived SCFA restrain the inflammatory phenotype of synovial CD4+ T cells and limit activation of monocytes and osteoclast-like cells. Thus, antibiotic-triggered gut dysbiosis exacerbates alphavirus arthritis by shaping the inflammatory profile of both infiltrating and resident immune cells in joint tissues.
Project description:Arthritogenic alphaviruses, including chikungunya virus (CHIKV), Mayaro virus and Ross River virus, cause long-lasting musculoskeletal pain and inflammation. However, the mechanisms driving chronic disease remain unclear. Here, we used single-cell RNA sequencing, spatial transcriptomics and flow cytometry to investigate joint-associated tissues in alphavirus-infected mice at a late stage of infection. We identified an accumulation of inflammatory macrophages in joint-associated tissues with elevated expression of inflammatory markers. These cells harbour CHIKV RNA, suggesting ongoing viral replication during chronic disease. We also identified an accumulation of CD4+ T cells in these tissues expressing Ifng, and found that depletion of CD4+ T cells diminished major histocompatibility complex class II expression on joint macrophages, highlighting their potential role in inflammation. Treatment with a small molecule inhibitor of CHIKV replication during chronic disease reduced viral RNA and joint inflammation. Our data suggest that macrophages harbour replicating viral RNA and contribute to the sustained joint inflammation associated with chronic alphavirus disease.
Project description:In this study, we aim to identify common host genes involved in pathogenesis of different Chikungunya virus strains as an attempt to recognize probable antiviral targets. We have compared the host gene regulation after infection of monkey kidney cell line (Vero) with two different wild type CHIKV strains i.e. S 27 (human, ECSA), and DRDE-06 (human, ECSA). Vero cells were mock infected or infected with two Chikungunya virus strains (S 27 and DRDE-06) and harvested at 8hpi and 18hpi. The total RNA was extracted and microarray was done using Agilent protocol.