LIF-Dependent Signaling: New Pieces in the Lego

LIF, a member of the IL6 family of cytokine, displays pleiotropic effects on various cell types and organs. Its critical role in stem cell models (e.g.: murine ES, human mesenchymal cells) and its essential non redundant function during the implantation process of embryos, in eutherian mammals, put this cytokine at the core of many studies aiming to understand its mechanisms of action, which could benefit to medical applications. In addition, its conservation upon evolution raised the challenging question concerning the function of LIF in species in which there is no implantation. We present the recent knowledge about the established and potential functions of LIF in different stem cell models, (embryonic, hematopoietic, mesenchymal, muscle, neural stem cells and iPSC). We will also discuss EVO-DEVO aspects of this multifaceted cytokine

Uncovering the Anticancer Potential of Murine Cytomegalovirus against Human Colon Cancer Cells

International audienceHuman cytomegalovirus (HCMV) components are often found in tumors, but the precise relationship between HCMV and cancer remains a matter of debate. Pro-tumor functions of HCMV were described in several studies, but an association between HCMV seropositivity and reduced cancer risk was also evidenced, presumably relying on recognition and killing of cancer cells by HCMV-induced lymphocytes. This study aimed at deciphering whether CMV influences cancer development in an immune-independent manner. Using immunodeficient mice, we showed that systemic infection with murine CMV (MCMV) inhibited the growth of murine carcinomas. Surprisingly, MCMV, but not HCMV, also reduced human colon carcinoma development in vivo. In vitro, both viruses infected human cancer cells. Expression of human interferon-β (IFN-β) and nuclear domain (ND10) were induced in MCMV-infected, but not in HCMV-infected human colon cancer cells. These results suggest a decreased capacity of MCMV to counteract intrinsic defenses in the human cellular host. Finally, immunodeficient mice receiving peri-tumoral MCMV therapy showed a reduction of human colon cancer cell growth, albeit no clinical sign of systemic virus dissemination was evidenced. Our study, which describes a selective advantage of MCMV over HCMV to control human colon cancer, could pave the way for the development of CMV-based therapies against cancer

J Am Soc Nephrol

The reported association of mTOR-inhibitor (mTORi) treatment with a lower incidence of cytomegalovirus (CMV) infection in CMV-seropositive (R+) kidney transplant recipients (KTR) remains unexplained. The incidence of CMV infection and T-cell profile was compared between mTORi- treated and mycophenolic acid (MPA)-treated KTR, and mTORi effects on T-cell phenotype and functions analyzed. In MPA-treated R+ KTR, both αβ and γδ T-cells displayed a more dysfunctional phenotype (PD-1+, CD85j+) at day 0 of transplantation in the 16 KTR with severe CMV infection when compared to the 17 KTR without or with spontaneously resolving CMV infection. In mTORi-treated patients (n= 27), the proportion of PD-1+ and CD85j+ αβ and γδ T cells decreased when compared to MPA-treated patients (n=44), as well as the frequency and severity of CMV infections. mTORi treatment also led to higher proportions of latedifferentiated and cytotoxic γδ T cells, and IFNγ-producing and cytotoxic αβ T cells. , mTORi increased proliferation, viability, and CMV-induced IFNγ production of T cells and (decreased PD-1 and CD85j expression in T cells that shifted to a more efficient EOMES Hobit profile. In γδ T cells the mTORi effect was related to increased TCR signaling. Severe CMV replication is associated with a dysfunctional T-cell profile and mTORi improve T-cell fitness in association with better control of CMV. A dysfunctional Tcell phenotype could provide a new biomarker to predict post-transplantation infection and to stratify patients who should benefit from mTORi treatment.Conjugués polymersomes-cellules T bio-inspirés et biomimétiques: un concept biohybride combinant thérapie cellulaire et vectorisatio