技术资料

Precise control of Wnt signaling is necessary for immune system development. In this study,we detected severely impaired development of all lymphoid lineages in mice,resulting from an N-ethyl-N-nitrosourea-induced mutation in the limb region 1-like gene (Lmbr1l),which encodes a membrane-spanning protein with no previously described function in immunity. The interaction of LMBR1L with glycoprotein 78 (GP78) and ubiquitin-associated domain-containing protein 2 (UBAC2) attenuated Wnt signaling in lymphocytes by preventing the maturation of FZD6 and LRP6 through ubiquitination within the endoplasmic reticulum and by stabilizing destruction complex" proteins. LMBR1L-deficient T cells exhibited hallmarks of Wnt/beta-catenin activation and underwent apoptotic cell death in response to proliferative stimuli. LMBR1L has an essential function during lymphopoiesis and lymphoid activation acting as a negative regulator of the Wnt/beta-catenin pathway." View Publication

Multiple myeloma (MM) is a tumor of plasma cells (PCs). Due to the intense immunoglobulin secretion,PCs are prone to endoplasmic reticulum stress and activate several stress-managing pathways,including autophagy. Indeed,autophagy deregulation is maladaptive for MM cells,resulting in cell death. CK1alpha,a pro-survival kinase in MM,has recently been involved as a regulator of the autophagic flux and of the transcriptional competence of the autophagy-related transcription factor FOXO3a in several cancers. In this study,we investigated the role of CK1alpha in autophagy in MM. To study the autophagic flux we generated clones of MM cell lines expressing the mCherry-eGFP-LC3B fusion protein. We observed that CK1 inhibition with the chemical ATP-competitive CK1 alpha/delta inhibitor D4476 resulted in an impaired autophagic flux,likely due to an alteration of lysosomes acidification. However,D4476 caused the accumulation of the transcription factor FOXO3a in the nucleus,and this was paralleled by the upregulation of mRNA coding for autophagic genes. Surprisingly,silencing of CK1alpha by RNA interference triggered the autophagic flux. However,FOXO3a did not shuttle into the nucleus and the transcription of autophagy-related FOXO3a-dependent genes was not observed. Thus,while the chemical inhibition with the dual CK1alpha/delta inhibitor D4476 induced cell death as a consequence of an accumulation of ineffective autophagic vesicles,on the opposite,CK1alpha silencing,although it also determined apoptosis,triggered a full activation of the early autophagic flux,which was then not supported by the upregulation of autophagic genes. Taken together,our results indicate that the family of CK1 kinases may profoundly influence MM cells survival also through the modulation of the autophagic pathway. View Publication

A proposed strategy to cure HIV uses latency-reversing agents (LRAs) to reactivate latent proviruses for purging HIV reservoirs. A variety of LRAs have been identified,but none has yet proven effective in reducing the reservoir size in vivo. Nanocarriers could address some major challenges by improving drug solubility and safety,providing sustained drug release,and simultaneously delivering multiple drugs to target tissues and cells. Here,we formulated hybrid nanocarriers that incorporate physicochemically diverse LRAs and target lymphatic CD4+ T cells. We identified one LRA combination that displayed synergistic latency reversal and low cytotoxicity in a cell model of HIV and in CD4+ T cells from virologically suppressed patients. Furthermore,our targeted nanocarriers selectively activated CD4+ T cells in nonhuman primate peripheral blood mononuclear cells as well as in murine lymph nodes,and substantially reduced local toxicity. This nanocarrier platform may enable new solutions for delivering anti-HIV agents for an HIV cure. View Publication

Chronic hepatitis C virus (HCV) infection causes generalized CD8+ T cell impairment,not limited to HCV-specific CD8+ T-cells. Liver-infiltrating monocyte-derived macrophages (MDMs) contribute to the local micro-environment and can interact with and influence cells routinely trafficking through the liver,including CD8+ T-cells. MDMs can be polarized into M1 (classically activated) and M2a,M2b,and M2c (alternatively activated) phenotypes that perform pro- and anti-inflammatory functions,respectively. The impact of chronic HCV infection on MDM subset functions is not known. Our results show that M1 cells generated from chronic HCV patients acquire M2 characteristics,such as increased CD86 expression and IL-10 secretion,compared to uninfected controls. In contrast,M2 subsets from HCV-infected individuals acquired M1-like features by secreting more IL-12 and IFN-gamma. The severity of liver disease was also associated with altered macrophage subset differentiation. In co-cultures with autologous CD8+ T-cells from controls,M1 macrophages alone significantly increased CD8+ T cell IFN-gamma expression in a cytokine-independent and cell-contact-dependent manner. However,M1 macrophages from HCV-infected individuals significantly decreased IFN-gamma expression in CD8+ T-cells. Therefore,altered M1 macrophage differentiation in chronic HCV infection may contribute to observed CD8+ T-cell dysfunction. Understanding the immunological perturbations in chronic HCV infection will lead to the identification of therapeutic targets to restore immune function in HCV+ individuals,and aid in the mitigation of associated negative clinical outcomes. View Publication