Transcription profiling of bone marrow derived macrophages in vitro-infected (Leishmania major) vs uninfected
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ABSTRACT: Gene expression profiles of in vitro-infected (Leishmania major) and uninfected bone-marrow-derived macrophages from BALB/c, C57BL/6, C.B6-(lmr1, lmr2) and B6.c-(lmr1, lmr2) mouse strains. We utilised microarrays to investigate a number of issues. Firstly, we determined which genes were differentially regulated in macrophages in response to infection with Leishmania major. Secondly, we hoped to gain some insight into the differences between C-B6-(lmr1, lmr2) congenic mice and their parental control BALB/c, as well as differences between B6-c-(lmr1, lmr2) and their parental control C57BL/6. This would aid us in the search for the genes underlying our loci, since the only genomic regions differing between the two strains are those of the two congenic intervals on chromosomes 9 and 17. Any genes differentially regulated would be contributing to the experimental infection differences observed between the congenic mice and their parental controls. Experiment Overall Design: L. major-infected and uninfected bone marrow-derived macrophages from C57BL/6, BALB/c, B6.c-(lmr1, lmr2) and C.B6-(lmr1, lmr2) mice were analyzed. Macrophages from 6 mice were pooled for each sample.
Project description:Gene expression profiles of in vitro-infected (Leishmania major) and uninfected bone-marrow-derived macrophages from BALB/c, C57BL/6, C.B6-(lmr1, lmr2) and B6.c-(lmr1, lmr2) mouse strains. We utilised microarrays to investigate a number of issues. Firstly, we determined which genes were differentially regulated in macrophages in response to infection with Leishmania major. Secondly, we hoped to gain some insight into the differences between C-B6-(lmr1, lmr2) congenic mice and their parental control BALB/c, as well as differences between B6-c-(lmr1, lmr2) and their parental control C57BL/6. This would aid us in the search for the genes underlying our loci, since the only genomic regions differing between the two strains are those of the two congenic intervals on chromosomes 9 and 17. Any genes differentially regulated would be contributing to the experimental infection differences observed between the congenic mice and their parental controls.
Project description:Leishmaniasis is a group of diseases caused by parasites of the genus Leishmania that affects millions of people worldwide. The disease outcome is determined by both the parasite species and the host's immune response. Leishmania major infection causes a localized cutaneous lesion in patients and has been widely used to study the development of T cell responses in mice. L. major infected C57BL/6 mice are resistant to infection due to the development of Th1 responses, whereas BALB/c mice develop a Th2 response resulting in disease susceptibility and failure to control parasite replication. However, these disparate host phenotypes are not observed with all Leishmania species. For example, during L. braziliensis infection both BALB/c and C57BL/6 mice are resistant. In order to better understand the host genetic basis underlying disease susceptibility in vivo, we performed a whole genome transcriptional analysis from skin lesions of BALB/c and C57BL/6 mice infected intradermally for 4 weeks with either L. braziliensis or L. major.
Project description:Murine bone marrow derived macrophages were infected with Leishmania major or Leishmania donovania promastigotes, allowed to phagocytose latex beads or not treated. Gene expression profiles were compared to identify i) the effect of Leishmania infection; ii) the differences in effects between L. major and L. donovani; and iii) the effect of pahgocytosis of latex beads.
Project description:The goal of this experiment was to identify genes which are differentially regulated between Leishmania major- infected granuloma macrophages from mice resistant (C57 Bl/6) and susceptible (BALB/c) to experimental leishmaniasis
Project description:Macrophages rapidly engulf apoptotic cells to limit the release of noxious cellular contents and to restrict autoimmune responses against self antigens. Although factors participating in recognition and engulfment of apoptotic cells have been identified, the transcriptional basis for the sensing and silently disposing of apoptotic cells is unknown. Here we show that peroxisome proliferator activated receptor delta (PPARdelta) is induced when macrophages engulf apoptotic cells and functions as a transcriptional sensor of dying cells. Genetic deletion of PPARdelta decreases expression of opsonins, such as C1qb, resulting in impairment of apoptotic cell clearance and reduction in anti-inflammatory cytokine production. This increases autoantibody production and predisposes global and macrophage-specific PPARdelta deficient mice to autoimmune kidney disease, a phenotype resembling the human disease systemic lupus erythematosus. Thus, PPARdelta plays a pivotal role in orchestrating the timely disposal of apoptotic cells by macrophages, ensuring that tolerance to self is maintained. HoxA9 immortalized ES cell derived myeloid precursors were created and differentiated as in Odegaard et al, 2007. After expansion, macrophages were differentiated for 8 days in the presence of MCSF in 20% L929 conditioned media with 2.5% bovine serum albumin in low glucose media. Macrophages were harvested for RNA using Qiagen's RNeasy Kit. A common reference was generated using e17.5 C57Bl/6 embryos. 30ug of either reference or macrophage RNA was labeled with Cy3 and Cy5 (Amersham) and hybridized to Stanford Functional Genomics Facility mouse cDNA microarrays for 16 hours. The arrays were washed and scanned on an Agilent G2505A ChipScan v. A.6.3.1. Florescence values were extracted using GenePix Pro v. 5.0.0.51. The data were normalized using regression correlation. Subsequently, missing values were imputed and significantly differentially expressed genes were found with Significance Analysis of Microarrays. For the Nature Medicine manuscript, significantly differentially expressed genes including genes involved in the process of uptake of apoptotic cells were extracted and clustered by complete linkage using Cluster and visualized using TreeView. Key to genotypes: "J1 untreated" are WT differentiated macrophages; "18 Untreated" are PPARd-/- differentiated macrophages Genotype: Wild type (WT) or PPAR delta minus (PPARd -/-) macrophages genetic_modification_design
Project description:Background and Aims: In the interleukin-10-deficient (Il10-/-) mouse model of IBD, 10 quantitative trait loci (QTL) have been shown to be associated with colitis susceptibility by linkage analyses on experimental crosses of highly susceptible C3H/HeJBir (C3Bir)-Il10-/- and partially resistant C57BL/6J (B6)-Il10-/- mice. The strongest locus (C3Bir-derived cytokine deficiency-induced colitis susceptibility [Cdcs]1 on Chromosome [Chr] 3) controlled multiple colitogenic subphenotypes and contributed the vast majority to the phenotypic variance in cecum and colon. This was demonstrated by interval-specific Chr 3 congenic mice wherein defined regions of Cdcs1 from C3Bir or B6 were bred into the IL-10-deficient reciprocal background and altered the susceptible or resistant phenotype. Furthermore, this locus likely acts by inducing innate hypo- and adaptive hyperresponsiveness, associated with impaired NFΚB responses of macrophages. The aim of the present study was to dissect the complexity of Cdcs1 by further development and characterization of reciprocal Cdcs1 congenic strains and to identify potential candidate genes in the congenic interval. Material and Methods: In total, 15 reciprocal congenic strains were generated from Il10-/- mice of either C3H/HeJBir or C57BL/6J backgrounds by 10 cycles of backcrossing. Colitis activity was monitored by histological grading. Candidate genes were identified by fine mapping of congenic intervals, sequencing, microarray analysis and a high-throughput real-time RT-PCR approach using bone marrow-derived macrophages. Results: Within the originally identified Cdcs1-interval, three independent regions were detected that likely contain susceptibility-determining genetic factors (Cdcs1.1, Cdcs1.2, and Cdcs1.3). Combining results of candidate gene approaches revealed Fcgr1, Cnn3, Larp7, and Alpk1 as highly attractive candidate genes with polymorphisms in coding or regulatory regions and expression differences between susceptible and resistant mouse strains. Conclusions: Subcongenic analysis of the major susceptibility locus Cdcs1 on mouse chromosome 3 revealed a complex genetic structure. Candidate gene approaches revealed attractive genes within the identified regions with homologs that are located in human susceptibility regions for IBD. Experiment Overall Design: Bone marrow derived macrophages (BMDM) of colitis susceptible C3Bir-Il10-/- and colitis resistant B6-Il10-/- as well as the Il10-/- reciprocal congenic strains CB-R1 (C3Bir genetic background carrying a long congenic chromosome 3 element containing Cdcs1 from B6, rendering this formerly susceptible background resistant) and BC-R3 (B6 genetic background that carries the Cdcs1-region of C3Bir) were cultured and stimulated with flagellin or left unstimulated. BMDM were obtained from 3 male mice per genotype and cultured in polystyrene 6-well culture plates. Before RNA-isolation, 3 wells per plate were stimulated with Cbir1 flagellin (and subsequently pooled for RNA isolation), the other 3 wells left unstimulated (and also pooled). In total, these experiments were replicated three times in order to perform microarray analyses in triplicates.
Project description:We previously constructed a congenic mouse, B6.S-D2Mit194-D2Mit311 (B6.S-2) with SPRET/Ei donor DNA on distal chromosome 2 in a C57BL/6J background that captured an obesity quantitative trait locus (QTL). Mice homozygous for SPRET/Ei alleles at the donor region had decreased body weight and obesity related phenotypes. The B6.S-2 congenic donor region spanned a minimum of 26 Mb. In this study, we constructed five overlapping subcongenics with smaller SPRET/Ei donor regions to fine map the underlying gene(s). One of the five subcongenic lines derived from the B6.S-2 founding congenic, B6.S-2A, captures most of the body weight and adiposity phenotypes in a donor region with a maximum size of 7.4 Mb. Homozygous SPRET/Ei donor alleles in both the founding congenic and the derived B6.S-2A subcongenic exhibit significant decreases in body weight, multiple fat pad weights with the greatest decrease in mesenteric fat pad weight, and Adiposity Index (total fat pad weight divided by body weight). Interval specific microarray analysis in four tissues for donor region genes from the founding B6.S-2 congenic identified several differentially expressed genes mapping to the B6.S-2A subcongenic donor region, including prohormone convertase 2 (PC2). Quantitative real-time PCR confirmed a modest decrease of PC2 expression in whole brains of mice homozygous for SPRET/Ei donor alleles. Analysis of the relative levels of mRNA for B6 and SPRET/Ei in heterozygous congenic mice showed differentially higher expression of the C57BL/6J allele over the SPRET/Ei allele indicating a cis regulation of differential expression. Using subcongenic mapping, we have successfully narrowed a body weight and obesity QTL interval and identified PC2 as a positional candidate gene. Keywords: Two strain comparison for gene discovery
Project description:Chemosensory epithelial tuft cells contribute to innate immunity at barrier surfaces, but their differentiation from epithelial progenitors is not well understood. Here we exploited differences between inbred mouse strains to identify an epithelium-intrinsic mechanism that regulates tuft cell differentiation and tunes innate type 2 immunity in the small intestine. Balb/cJ (Balb) mice had fewer intestinal tuft cells than C57BL/6J (B6) mice and failed to respond to the tuft cell ligand succinate. A majority of this differential succinate response was determined by a single genetic locus from 50-67Mb on chromosome 9 (Chr9). Congenic Balb mice carrying the B6 Chr9 locus had elevated baseline numbers of tuft cells and responded to succinate. The Chr9 locus includes Pou2af2, a transcriptional cofactor essential for tuft cell development. Epithelial crypts expressed a previously unannotated short isoform of Pou2af2 that uses a novel transcriptional start site and encodes a non-functional protein. Low tuft cell numbers and the resulting lack of succinate response in Balb mice was explained by a preferential expression of the short isoform. Physiologically, differential Pou2af2 isoform usage tuned innate type 2 immunity in the small intestine. Balb mice maintained responsiveness to helminth pathogens while ignoring commensal Tritrichomonas protists and reducing norovirus burdens.
Project description:We identified a congenic mouse with an introgressed region from the A/J donor inbred strain on an inbred C57BL/6J background that showed a reduced locomotor stimulant response to methamphetamine. We conducted microarray analysis of the striatum from drug-naive female and male mice that were 6-9 weeks old. The congenic region is on chromosome 11 and spans approximately 84-96 Mb. There were two groups of mice used in the analysis: B6 control mice versus congenic mice. Congenic mice were collapsed across heterozygous and homozygous genotypes. All mice are on a C57BL/6J background. Congenic mice differ only on chromosome 11 where they contain the introgressed A/J alleles from 84-96 Mb.
Project description:Background and Aims: In the interleukin-10-deficient (Il10-/-) mouse model of IBD, 10 quantitative trait loci (QTL) have been shown to be associated with colitis susceptibility by linkage analyses on experimental crosses of highly susceptible C3H/HeJBir (C3Bir)-Il10-/- and partially resistant C57BL/6J (B6)-Il10-/- mice. The strongest locus (C3Bir-derived cytokine deficiency-induced colitis susceptibility [Cdcs]1 on Chromosome [Chr] 3) controlled multiple colitogenic subphenotypes and contributed the vast majority to the phenotypic variance in cecum and colon. This was demonstrated by interval-specific Chr 3 congenic mice wherein defined regions of Cdcs1 from C3Bir or B6 were bred into the IL-10-deficient reciprocal background and altered the susceptible or resistant phenotype. Furthermore, this locus likely acts by inducing innate hypo- and adaptive hyperresponsiveness, associated with impaired NFΚB responses of macrophages. The aim of the present study was to dissect the complexity of Cdcs1 by further development and characterization of reciprocal Cdcs1 congenic strains and to identify potential candidate genes in the congenic interval. Material and Methods: In total, 15 reciprocal congenic strains were generated from Il10-/- mice of either C3H/HeJBir or C57BL/6J backgrounds by 10 cycles of backcrossing. Colitis activity was monitored by histological grading. Candidate genes were identified by fine mapping of congenic intervals, sequencing, microarray analysis and a high-throughput real-time RT-PCR approach using bone marrow-derived macrophages. Results: Within the originally identified Cdcs1-interval, three independent regions were detected that likely contain susceptibility-determining genetic factors (Cdcs1.1, Cdcs1.2, and Cdcs1.3). Combining results of candidate gene approaches revealed Fcgr1, Cnn3, Larp7, and Alpk1 as highly attractive candidate genes with polymorphisms in coding or regulatory regions and expression differences between susceptible and resistant mouse strains. Conclusions: Subcongenic analysis of the major susceptibility locus Cdcs1 on mouse chromosome 3 revealed a complex genetic structure. Candidate gene approaches revealed attractive genes within the identified regions with homologs that are located in human susceptibility regions for IBD.