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Genetic mapping and genome-wide studies provide evidence for the association of several genetic polymorphisms with malaria, a complex pathological disease with multiple severity degrees. We have previously described Berr1and Berr2 as candidate genes identified in the WLA/Pas inbreed mouse strain predisposing to resistance to cerebral malaria (CM) induced by P. berghei ANKA. We report in this study the phenotypic and functional characteristics of a congenic strain we have derived for Berr2WLA allele on the C57BL/6JR (B6) background. B6.WLA-Berr2 was found highly resistant to CM compared to C57BL/6JR susceptible mice. The mechanisms associated with CM resistance were analyzed by combining genotype, transcriptomic and immune response studies. We found that B6.WLA-Berr2 mice showed a reduced parasite sequestration and blood-brain barrier disruption with low CXCR3+ T cell infiltration in the brain along with altered glial cell response upon P. berghei ANKA infection compared to B6. In addition, we have identified the CD300f, belonging to a family of Ig-like encoding genes, as a potential candidate associated with CM resistance. Microglia cells isolated from the brain of infected B6.WLA-Berr2 mice significantly expressed higher level of CD300f compared to CMS mice and were associated with inhibition of inflammatory response.

Summary During normal mammary gland development, s-SHIP promoter expression marks a distinct type of mammary stem cells, at two different stages, puberty and early mid-pregnancy. To determine whether s-SHIP is a marker of mammary cancer stem cells (CSCs), we generated bitransgenic mice by crossing the C3(1)-SV40 T-antigen transgenic mouse model of breast cancer, and a transgenic mouse (11.5kb-GFP) expressing green fluorescent protein from the s-SHIP promoter. Here we show that in mammary tumors originating in these bitransgenic mice, s-SHIP promoter expression enriches a rare cell population with CSC activity as demonstrated by sphere-forming assays in vitro and limiting dilution transplantation in vivo. These s-SHIP-positive CSCs are characterized by lower expression of Delta-like non-canonical Notch ligand 1 (DLK1), a negative regulator of the Notch pathway. Inactivation of Dlk1 in s-SHIP-negative tumor cells increases their tumorigenic potential, suggesting a role for DLK1 in mammary cancer stemness., Highlights • A rare s-SHIP+ cell subset is present in mouse basal-like mammary tumors • s-SHIP+ tumor cells display higher sphere-forming potential • s-SHIP+ tumor cells have higher tumorigenicity • Downregulation of Dlk1 increases tumorigenicity, Bourette and colleagues assess renewal and differentiation potential of s-SHIP-expressing cells in mouse mammary tumors, by in vitro sphere-forming assay and in vivo transplantation. Their data indicate that s-SHIP expression marks a distinct population of mammary cancer stem cells and unveils a potential role of Dlk1, a negative regulator of the Notch pathway, in the regulation of mammary tumor cell stemness.

// Guillaume Brocqueville 1 , Renee S. Chmelar 2 , Helene Bauderlique-Le Roy 1 , Emeric Deruy 3 , Lu Tian 1 , Robert L. Vessella 4 , Norman M. Greenberg 2, 5 , Larry R. Rohrschneider 2, * , Roland P. Bourette 1 1 University of Lille, CNRS, Institut Pasteur de Lille, UMR 8161-M3T-Mechanisms of Tumorigenesis and Targeted Therapies, SIRIC ONCOLille, F-59000 Lille, France 2 Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA 3 BioImaging Center Lille, Institut Pasteur de Lille, University of Lille, F-59000 Lille, France 4 Department of Urology, University of Washington, Seattle, WA 98195, USA 5 Present address: NMG Scientific Consulting, North Potomac, MD 20878, USA * Deceased Correspondence to: Roland P. Bourette, e-mail: roland.bourette@ibl.cnrs.fr Keywords: stem cells, prostate, s-SHIP, epithelial cells, transgenic mouse Received: November 04, 2015 Accepted: March 28, 2016 Published: April 12, 2016 ABSTRACT Isolation of prostate stem cells (PSCs) is crucial for understanding their biology during normal development and tumorigenesis. In this aim, we used a transgenic mouse model expressing GFP from the stem cell-specific s-SHIP promoter to mark putative stem cells during postnatal prostate development. Here we show that cells identified by GFP expression are present transiently during early prostate development and localize to the basal cell layer of the epithelium. These prostate GFP + cells are a subpopulation of the Lin – CD24 + Sca-1 + CD49f + cells and are capable of self-renewal together with enhanced growth potential in sphere-forming assay in vitro , a phenotype consistent with that of a PSC population. Transplantation assays of prostate GFP + cells demonstrate reconstitution of prostate ducts containing both basal and luminal cells in renal grafts. Altogether, these results demonstrate that s-SHIP promoter expression is a new marker for neonatal basal prostate cells exhibiting stem cell properties that enables PSCs in situ identification and isolation via a single consistent parameter. Transcriptional profiling of these GFP + neonatal stem cells showed an increased expression of several components of the Wnt signaling pathway. It also identified stem cell regulators with potential applications for further analyses of normal and cancer stem cells.