A proliferation-inducing ligand (APRIL) (also known as TALL-2 and TRDL-1) is a member of the tumor necrosis factor (TNF) superfamily that has tumorigenic properties but is also important for the induction of humoral immune responses. APRIL binds two TNF receptors: transmembrane activator and calcium modulator and cyclophilin ligand interactor (TACI) and B-cell maturation antigen (BCMA) as well as heparan sulfate proteoglycans (HSPGs). The aim of this study was to clarify the role of the HSPG interaction in canonical APRIL signaling, because it has been proposed to act as a docking site and also to play a role in direct signaling. In this study, we generated point mutants of soluble APRIL that lack either the capacity to bind HSPGs or TACI and BCMA and then tested the function of these mutants in mouse B-cell assays. In contrast to previous reports, we found that APRIL alone is sufficient to costimulate B-cell proliferation and drive IgA production and does not require artificial antibody cross-linking. We found no evidence that APRIL requires signaling through HSPGs but, notably, were able to show that binding of APRIL to HSPGs is crucial for mediating natural APRIL cross-linking to allow for optimal activation of murine B cells.

Abstract-Visible light communications (VLC) has the potential to play a major part in future smart home and next generation communication networks. There is significant ongoing work to increase the achievable data rates using VLC, to standardize it and integrate it within existing network infrastructures.The future of VLC systems depends on the ability to fabricate low cost transceiver components and to realize the promise of high data rates. This paper reports the design and fabrication of integrated transmitter and receiver components. The transmitter uses a two dimensional individually addressable array of micro light emitting diodes (µLEDs) and the receiver uses an integrated photodiode array fabricated in a CMOS technology. A preliminary result of a MIMO system implementation operating at a data rate of ~1Gbps is demonstrated. This paper also highlights the challenges in achieving highly parallel data communication along with the possible bottlenecks in integrated approaches. IndexTerms-Visible light communications, Optical communication system design, multiple input multiple output, optical wireless communications, link budget analysis, integrated optical system design.

Purpose: High expression of cancer stem cell (CSC) marker CD133 has been used as a predictor for prognosis in colorectal cancer (CRC), suggesting that enumeration of CSCs, using CD133, is predictive for disease progression. However, we showed recently that both CD133 mRNA and protein are not downregulated during differentiation of colon CSCs, pointing to an alternative reason for the prognostic value of CD133. We therefore set out to delineate the relation between CD133 expression and prognosis.Experimental Design: A CRC patient series was studied for expression of CD133 and other CSC markers by microarray and quantitative PCR analysis. In addition, several common mutations were analyzed to determine the relation with CD133 expression.Results: CD133 mRNA expression predicted relapse-free survival in our patient series, whereas several other CSC markers could not. Moreover, no correlation was found between expression of other CSC markers and CD133. Interestingly, high CD133 expression was related to mutations in K-Ras and B-Raf, and inhibition of mutant K-Ras or downstream mitogen-activated protein kinase kinase (MEK) signaling decreases CD133 expression. In addition, an activated K-Ras gene expression signature could predict CD133 expression in our patient set as well as data sets of other tumor types.Conclusion: CD133 expression is upregulated in CRC tumors that have a hyperactivated RasRaf-MEK-ERK pathway and is therefore related to mutations in K-Ras or B-Raf. As mutations in either gene have been related to poor prognosis, we conclude that CD133 expression is not indicative for CSC numbers but rather related to the mutation or activity status of the Ras-Raf pathway. Clin Cancer Res; 18(11); 3132-41. Ó2012 AACR.

SummaryIn this study, human embryonic stem cell-derived hepatocytes (hESC-Heps) were investigated for their ability to support hepatitis C virus (HCV) infection and replication. hESC-Heps were capable of supporting the full viral life cycle, including the release of infectious virions. Although supportive, hESC-Hep viral infection levels were not as great as those observed in Huh7 cells. We reasoned that innate immune responses in hESC-Heps may lead to the low level of infection and replication. Upon further investigation, we identified a strong type III interferon response in hESC-Heps that was triggered by HCV. Interestingly, specific inhibition of the JAK/STAT signaling pathway led to an increase in HCV infection and replication in hESC-Heps. Of note, the interferon response was not evident in Huh7 cells. In summary, we have established a robust cell-based system that allows the in-depth study of virus-host interactions in vitro.