Project description:The systematic temporal gene expression analysis of primary macrophages activated under immune (interferon-gamma) and productive viral infection with murine cytomegalovirus (mCMV). The primary objective of the study is to define, in an unbiased manner, cause-and-effect relationships in the program of gene activation in this cellular system. The even spacing and time intervals (every 30 minutes) makes this study amenable to modelling of gene networks in the system.
Project description:The systematic temporal gene expression analysis of primary macrophages activated under immune (interferon-gamma (IFN-g)) and productive viral infection with murine cytomegalovirus (mCMV). The primary objective of the study is to define, in an unbiased manner, cause-and-effect relationships in the program of gene activation in this cellular system. The even spacing and time intervals (every 30 minutes) makes this study amenable to modelling of gene networks in the system.
Project description:The cytokine interferon-γ is a principal effector of macrophage activation and immune resistance to mycobacterial infection; however, pathogenic mycobacteria are capable of surviving in interferon-γ-activated macrophages by largely unknown mechanisms. We found that interferon-γ specifically bound to pathogenic mycobacteria and enhanced their growth in culture. Proteomic and electron microscopy analyses revealed that interferon-γ directly triggers proliferative activity and virulence phenotype in pathogenic mycobacteria that allow them to survive and grow inside macrophages. These findings suggest that pathogenic mycobacteria may have evolved eukaryotic-like signal transduction mechanisms to recognize host-protective immune activation.
Project description:Toxoplasma strains are known to inhibit the expression of several interferon-gamma induced genes, and a type II strain was shown to dysregulate genome-wide responses to interferon-gamma in human fibroblasts (Kim et al., 2007, J Immunol.). In this study we aimed to determine the effect of infection with three clonal lineages of Toxoplasma, type I, II, and III strains on genome-wide interferon-gamma induced transcription in murine macrophages. We also assessed the effect of the two main Toxoplasma modulators of mouse macrophage transcription, ROP16 and GRA15 (Jensen et al., 2011, Cell Host Microbe). We used Affymetrix microarrays to analyze host cell transcription after Toxoplasma infection and interferon-gamma stimulation. RAW264.7 murine macrophages were left uninfected or infected with type I (RH), type I ?rop16 (RH ?rop16), type II (Pru), type II ?gra15 (Pru ?gra15), or type II (CEP) parasites at an MOI ~5 for 18 hours and subsequently stimulated with murine IFN-? for six hours. Plaque assays were done to assess parasite viability. Total RNA was isolated and hybridized to Affymetrix Mouse 430A 2.0 gene chips.
Project description:The systematic temporal gene expression analysis of primary macrophages activated under immune (interferon-gamma) and productive viral infection with murine cytomegalovirus (mCMV). The primary objective of the study is to define, in an unbiased manner, cause-and-effect relationships in the program of gene activation in this cellular system. The even spacing and time intervals (every 30 minutes) makes this study amenable to modelling of gene networks in the system. A kinetic analysis of mCMV infection on the gene expression of murine (BALB/c) bone marrow-derived macrophages (BMDMs) over the first 12 hours, sampling every 30 minutes. Agilent mouse genome arrays were used to determine the differences in gene expression between mock and mCMV infected. The 25 samples collected for the mock infected were pooled and treated as a pooled control. Pooled control was labelled with Cy3 dye and hybridised with every other sample (labelled with Cy5 dye) = 25 dual-dye array hybridisations. The reference channel of the dual-channel hybridisations was only used to normalise the expression of the test channel, rather than used to calculate ratio data. Thus, the normalised data represent log2 single-channel data.
Project description:The systematic temporal gene expression analysis of primary macrophages activated under immune (interferon-gamma (IFN-g)) and productive viral infection with murine cytomegalovirus (mCMV). The primary objective of the study is to define, in an unbiased manner, cause-and-effect relationships in the program of gene activation in this cellular system. The even spacing and time intervals (every 30 minutes) makes this study amenable to modelling of gene networks in the system. A kinetic analysis of IFN-g treatment on the gene expression of murine (BALB/c) bone marrow-derived macrophages (BMDMs) over the first 12 hours, sampling every 30 minutes. Agilent mouse genome arrays were used to determine the differences in gene expression between mock and IFN-g treated. The 25 samples collected for the mock IFN-g treatment were pooled and treated as a pooled control. Pooled control was labelled with Cy3 dye and hybridised with every other sample (labelled with Cy5 dye) = 25 dual-dye array hybridisations. The reference channel of the dual-channel hybridisations was only used to normalise the expression of the test channel, rather than used to calculate ratio data. Thus, the normalised data represent log2 single-channel data.
Project description:Macrophages represent multifunctional leukocytes defined by their stimulus-specific transcriptional reprogramming. As in vivo macrophages are often difficult to obtain, in vitro macrophage models are often used. We aggregated public expression data to define consensus expression profiles for eight commonly-used in vitro macrophage models and built the classifier macIDR, capable of distinguishing macrophage subsets with high accuracy (>0.95). Classification of in vivo macrophages suggested that alveolar macrophages resembled interleukin-10 activated macrophages in general whereas chronic obstructive pulmonary disease patients displayed decreased similarity to interferon-γ stimulated macrophages. Adipose tissue-derived macrophages were classified as unstimulated macrophages, but would resemble LPS-stimulated macrophages more in diabetic-obese patients. Rheumatoid arthritic synovial macrophages were similar to macrophages stimulated with interleukin-10 or interferon-γ. Altogether, our results suggest that macIDR is capable of identifying in vitro macrophages. By projecting in vivo macrophages onto the in vitro macrophages, we were capable of elucidating macrophage-specific changes as a result of tissue and disease.
Project description:Ultraviolet (UV) radiation is a major melanoma risk factor, yet underlying mechanisms remain poorly understood. Here we introduce a mouse model permitting fluorescence-aided melanocyte imaging and isolation following in vivo UV irradiation. We use expression profiling to show that activated neonatal skin melanocytes isolated following a melanomagenic UVB dose bear a distinct, persistent interferon-response signature, including genes associated with immunoevasion. UVB-induced melanocyte activation, characterized by aberrant growth and migration, was abolished by antibody-mediated systemic blockade of interferon-gamma (IFN-gamma), but not type-I interferons. IFN-gamma was produced by macrophages recruited to neonatal skin by UVB-induced chemokine receptor Ccr2 ligands. Admixed recruited skin macrophages enhanced transplanted melanoma growth by inhibiting apoptosis; notably, IFN-gamma blockade abolished macrophage-associated melanoma growth and survival. IFN-gamma-producing macrophages were identified in 70% of human melanomas examined. Our data reveal an unanticipated role for IFN-gamma in promoting melanocytic cell survival/immunoevasion, and suggest IFN-gamma-R signaling represents a novel therapeutic melanoma target. Biologic replicates of UVA- and UVB-treated mouse melanocytes, as well as untreated mouse melanocytes and mouse keratinocytes, were used to define melanocyte expression signatures associated with UV treatment.