Comparative Study on the Therapeutic Potential of Neurally Differentiated Stem Cells in a Mouse Model of Multiple Sclerosis

Background: Transplantation of neural stem cells (NSCs) is a promising novel approach to the treatment of neuroinflammatory diseases such as multiple sclerosis (MS). NSCs can be derived from primary central nervous system (CNS) tissue or obtained by neural differentiation of embryonic stem (ES) cells, the latter having the advantage of readily providing an unlimited number of cells for therapeutic purposes. Using a mouse model of MS, we evaluated the therapeutic potential of NSCs derived from ES cells by two different neural differentiation protocols that utilized adherent culture conditions and compared their effect to primary NSCs derived from the subventricular zone (SVZ). Methodology/Principal Findings: The proliferation and secretion of pro-inflammatory cytokines by antigen-stimulated splenocytes was reduced in the presence of SVZ-NSCs, while ES cell-derived NSCs exerted differential immunosuppressive effects. Surprisingly, intravenously injected NSCs displayed no significant therapeutic impact on clinical and pathological disease outcomes in mice with experimental autoimmune encephalomyelitis (EAE) induced by recombinant myelin oligodendrocyte glycoprotein, independent of the cell source. Studies tracking the biodistribution of transplanted ES cellderived NSCs revealed that these cells were unable to traffic to the CNS or peripheral lymphoid tissues, consistent with the lack of cell surface homing molecules. Attenuation of peripheral immune responses could only be achieved through multiple high doses of NSCs administered intraperitoneally, which led to some neuroprotective effects within the CNS

The implication of amino acid mutations at flavivirus NS1-2A cleavage site on NS1’ protein production

Aims: The presence of a C-terminally extended form of NS1 (NS1’ protein) has been previously reported in encephalitic flaviviruses, due to the presence of -1 programmed ribosomal frameshift at the N-terminal of NS2A protein. This present study is aimed to further confirm that the NS1’ protein production is independent of the authentic cleavage at NS1-2A junction. Methodology and results: Six different constructs (P1-Leu, P2-Asp, P3-Phe, P3-Leu, P3-Gly and P5-8 Ala) containing various mutations at conserved and variable amino acids at C-terminal of NS1 protein were generated by site-directed mutagenesis and analysed with transient polyprotein expression assay. While analysis on the NS1-2A cleavage of the mutants exhibited extremely poor to efficient cleavage ranging from 6-89%, significant amount of NS1’ being expressed in all mutants irrespective of their NS1-2A cleavage outcome. Conclusion, significance and impact study: In this analysis, we showed for the first time that the abolishment of the authentic NS1-2A cleavage in Murray Valley encephalitis virus (MVEV) did not impact on NS1’ production. This observation extend on previous studies to show that NS1 and NS2A proteins are the product of NS1-2A cleavage which is catalysed by an unknown host protease while NS1’ protein is a product of ribosomal frameshift, independent of the authentic cleavage at NS1-2A junction.This work was supported by a grant from National Health & Medical Research Council (NHMRC) of Australia

Restricted Semliki Forest virus replication in communication perforin and Fas-ligand double-deficient mice

Previously, we have shown that mice defective in granule exocytosis and/or Fas.L/Fas-mediated cytolytic pathways are significantly more resistant to alphavirus, Semliki Forest virus (SFV), infection compared with wild-type mice. Here, we evaluated SFV replication in different tissues of mice defective in both cytolytic pathways (perf−/−xgld) relative to that in wild-type counterparts and found that viral replication in perf−/−xgld mice is remarkably restricted. Although the mechanism responsible for this observation is yet to be established, the lower virus titres found in these mice indicate that the role of cytolytic effector molecules in antiviral immunity needs to be re-evaluated.Mohammed Alsharifi, Mario Lobigs, Jayaram Bettadapura, Aulikki Koskinen and Arno Müllbache

Mouse Interferons: Amino Terminal Amino Acid Sequences of Various Species

Mouse interferons of three size classes (A, 35,000 to 40,000 daltons; B, 26,000 to 33,000 daltons; and C, 20,000 daltons) were purified from Ehrlich ascites tumor cells infected with Newcastle disease virus. The sequences of the first 24 amino acids (No.17 has not been identified) of interferons A and B are identical. The sequence of the first 20 amino acids of interferon C differs from that of A and B in 18 positions. There is partial homology in amino terminal sequence between mouse interferons A (or B) and a human fibroblast interferon and between mouse interferon C and a human lymphoblastoid interferon

Characterization of Barmah Forest virus pathogenesis in a mouse model

Alphaviruses including Barmah Forest virus (BFV) and Ross River virus (RRV) cause arthritis, arthralgia and myalgia in humans. The rheumatic symptoms in human BFV infection are very similar to those of RRV. Although RRV disease has been studied extensively, little is known about the pathogenesis of BFV infection. We sought to establish a mouse model for BFV to facilitate our understanding of BFV infectivity, tropism and pathogenesis, and to identify key pathological and immunological mechanisms of BFV infection that may distinguish between infections with BFV and RRV. Here, to the best of our knowledge, we report the first study assessing the virulence and replication of several BFV isolates in a mouse model. We infected newborn Swiss outbred mice with BFV and established that the BFV2193 prototype was the most virulent strain. BFV2193 infection resulted in the highest mortality among all BFV variant isolates, comparable to that of RRV. In comparison with RRV, C57BL/6 mice infected with BFV showed delayed onset, moderate disease scores and early recovery of the disease. BFV replicated poorly in muscle and did not cause the severe myositis seen in RRV-infected mice. The mRNAs for the inflammatory mediators TNF-α, IL-6, CCL2 and arginase-1 were highly upregulated in RRV- but not BFV-infected muscle. To our knowledge, this is the first report of a mouse model of BFV infection, which we have used to demonstrate differences between BFV and RRV infections and to further understand disease pathogenesis. With an increasing number of BFV cases occurring annually, a better understanding of the disease mechanisms is essential for future therapeutic development

Extraction of informative regions of a face for facial expression recognition

The aim of facial expression recognition (FER) algorithms is to extract discriminative features of a face. However, discriminative features for FER can only be obtained from the informative regions of a face. Also, each of the facial subregions have different impacts on different facial expressions. Local binary pattern (LBP) based FER techniques extract texture features from all the regions of a face, and subsequently the features are stacked sequentially. This process generates the correlated features among different expressions, and hence affects the accuracy. This research moves toward addressing these issues. The authors' approach entails extracting discriminative features from the informative regions of a face. In this view, they propose an informative region extraction model, which models the importance of facial regions based on the projection of the expressive face images onto the neural face images. However, in practical scenarios, neutral images may not be available, and therefore the authors propose to estimate a common reference image using Procrustes analysis. Subsequently, weighted‐projection‐based LBP feature is derived from the informative regions of the face and their associated weights. This feature extraction method reduces miss‐classification among different classes of expressions. Experimental results on standard datasets show the efficacy of the proposed method

Phrenic nerve palsy in a patient of Churg Strauss syndrome and mononeuritis multiplex

Neurological manifestations like mononeuritis multiplex are seen commonly in patients with Churg Strauss syndrome. Cranial nerve involvement and central nervous system involvement are also reported, although infrequently. Phrenic nerve involvement has not been reported so far. We report a patient with Churg Strauss syndrome who presented with mononeuritis multiplex and developed left-sided phrenic nerve palsy subsequently