Parasitic organisms have evolved specialized strategies to evade immune defense mechanisms. We describe herein an ortholog of the cytokine, macrophage migration inhibitory factor (MIF), which is produced by the obligate intracellular parasite, Leishmania major. The Leishmania MIF protein, Lm1740MIF, shows significant structural homology with human MIF as revealed by a high-resolution x-ray crystal structure (1.03 Å). Differences between the two proteins in the N-terminal tautomerization site are evident, and we provide evidence for the selective, species-specific inhibition of MIF by small-molecule antagonists that target this site. Lm1740MIF shows significant binding interaction with the MIF receptor, CD74 (Kd = 2.9 × 10−8 M). Like its mammalian counterpart, Lm1740MIF induces ERK1/2 MAP kinase activation in a CD74-dependent manner and inhibits the activation-induced apoptosis of macrophages. The ability of Lm1740MIF to inhibit apoptosis may facilitate the persistence of Leishmania within the macrophage and contribute to its evasion from immune destruction.

To characterize temporal patterns of transcriptional activity during normal lung development, we generated genome wide gene expression data for 26 pre- and post-natal time points in three common inbred strains of laboratory mice (C57BL/6J, A/J, and C3H/HeJ). Using Principal Component Analysis and least squares regression modeling, we identified both strain-independent and strain-dependent patterns of gene expression. The 4,683 genes contributing to the strain-independent expression patterns were used to define a murine Developing Lung Characteristic Subtranscriptome (mDLCS). Regression modeling of the Principal Components supported the four canonical stages of mammalian embryonic lung development (embryonic, pseudoglandular, canalicular, saccular) defined previously by morphology and histology. For postnatal alveolar development, the regression model was consistent with four stages of alveolarization characterized by episodic transcriptional activity of genes related to pulmonary vascularization. Genes expressed in a strain-dependent manner were enriched for annotations related to neurogenesis, extracellular matrix organization, and Wnt signaling. Finally, a comparison of mouse and human transcriptomics from pre-natal stages of lung development revealed conservation of pathways associated with cell cycle, axon guidance, immune function, and metabolism as well as organism-specific expression of genes associated with extracellular matrix organization and protein modification. The mouse lung development transcriptome data generated for this study serves as a unique reference set to identify genes and pathways essential for normal mammalian lung development and for investigations into the developmental origins of respiratory disease and cancer. The gene expression data are available from the Gene Expression Omnibus (GEO) archive (GSE74243). Temporal expression patterns of mouse genes can be investigated using a study specific web resource (http://lungdevelopment.jax.org).

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Aim: Measurement of HDL subclasses provides insight into lipoprotein metabolism and helps predict risk for cardiovascular disease (CVD). HDL subclasses have been studied using biochemical tools in humans, but extensive studies on the role of HDL subclasses and their protein compositions in HDL metabolism have not been conducted using an animal model. In this study, we established a method to identify HDL subclasses in mice and compared HDL subclasses and the protein cargoes associated with them in three inbred strains of mice. Methods: We used a chemical precipitation method described by Warnick et al. in 1982, to identify HDL subclasses. In this method, LDL and VLDL are precipitated out from the serum using dextran sulfate and magnesium chloride solutions. Subsequently, HDL subclass distribution on gels was compared among male mice from 3 inbred strains with low (CAST/EiJ), normal (C57BL/6J) and high (NZB/BINJ) levels of HDL cholesterol (HDL-C). HDL subclasses were visualised by Coomassie Staining and Mass Spectrometry (MS) was done to confirm the presence of ApoA1, a constituent protein of HDL. Results: We observed that CAST/EiJ and NZB/BINJ had significantly different patterns of distribution of HDL subclasses compared to C57BL/6J mice. Furthermore, HDL subclasses from C57BL/6J and NZB/BINJ mice were subjected to quantitative MS. 106 proteins were associated with HDL particles in both strains, 47 proteins were unique to C57BL/6J HDL particles and 7 were unique to NZB/BINJ HDL particles. Using the Ingenuity Pathways Analysis we found that 30 molecules (27%) in NZB/BINJ and 33 (22%) in C57BL/6J mice had well characterized roles in lipid metabolism. 22 proteins that were previously identified as HDL associated in humans were identified in mice as well and 38 proteins were identified to be associated exclusively with mouse HDL in this study. Conclusion: Protein cargoes associated with HDL define its biological function. Thus, differences in HDL subclasses and HDL-associated proteins could potentially affect HDL function in these mouse-inbred strains, which ultimately could influence the development of CVD. Figure: HDL subclasses present in 10-week old C57BL/6J mice (gel was stained with Coomassie Dye to visualize the subclasses; MS was done to confirm presence of ApoA1, a constituent protein of HDL)