Two species of primates, Owl and African green monkeys, were inoculated intracerebrally with either the neurotropic mouse hepatitis virus JHM or the putative multiple sclerosis brain coronavirus isolate SD. These viruses caused an acute to subacute panencephalitis and/or demyelination in the infected animals. The course of pathogenesis and sites of detected viral RNA and antigen was dependent both on animal species and virus strain but the results clearly showed that these viruses replicated and disseminated in the central nervous system (CNS) of these primates. This study suggests that human CNS may be susceptible to coronavirus infection.

Critical role of extracellular heat shock cognate protein 70 in the myocardial inflammatory response and cardiac dysfunction after global ischemia-reperfusion. Am J Physiol Heart Circ Physiol 294: H2805-H2813, 2008. First published April 25, 2008 doi:10.1152/ajpheart.00299.2008.-Previous studies showed that Toll-like receptor 4 (TLR4) modulates the myocardial inflammatory response to ischemia-reperfusion injury, and we recently found that cytokines link TLR4 to postischemic cardiac dysfunction. Although TLR4 can be activated in cultured cells by endogenous agents including heat shock protein 70, how it is activated during myocardial ischemia-reperfusion is unknown. In the present study, we examined 1) whether heat shock cognate protein 70 (HSC70), which is constitutively expressed in the myocardium, is released during ischemia-reperfusion; 2) whether extracellular HSC70 induces the myocardial inflammatory response and modulates cardiac function; and 3) whether HSC70 exerts these effects via TLR4. We subjected isolated mouse hearts to global ischemia-reperfusion via the Langendorff technique. Immunoblotting and immunostaining detected the release of HSC70 from the myocardium during reperfusion. Treatment with an antibody specific to HSC70 suppressed myocardial cytokine expression and improved cardiac functional recovery after ischemia-reperfusion. Recombinant HSC70 induced NF-B activation and cytokine expression and depressed myocardial contractility in a TLR4-dependent manner. These effects required the substratebinding domain of HSC70. Fluorescence resonance energy transfer analysis of isolated macrophages demonstrated that extracellular HSC70 interacts with TLR4. Therefore, this study demonstrates for the first time that 1) the myocardium releases HSC70 during ischemiareperfusion, 2) extracellular HSC70 contributes to the postischemic myocardial inflammatory response and to cardiac dysfunction, 3) HSC70 exerts these effects through a TLR4-dependent mechanism, and 4) the substrate-binding domain of HSC70 is required to induce these effects. Thus extracellular HSC70 plays a critical role in regulating the myocardial innate immune response and cardiac function after ischemia-reperfusion.Toll-like receptor 4; cytokines; nuclear factor-B; messenger ribonucleic acid CARDIAC SURGERY OFTEN INVOLVES obligatory global myocardial ischemia-reperfusion, which causes a myocardial inflammatory response characterized by cytokine production (16, 18). Several proinflammatory cytokines, including TNF-␣, IL-1␤, and IL-6, contribute to myocardial injury after ischemia-reperfusion (12, 31). Preserving cardiac function after global ischemia-reperfusion therefore requires regulation of the myocardial inflammatory response. However, the signaling mechanisms underlying the myocardial inflammatory response to global ischemia-reperfusion are unclear.Previous studies implicated Toll-like receptor 4 (TLR4) signaling in the inflammatory response associated with myocardial ischemia-reperfusion injury. In mice treated with the TLR4 antagonis...

After primary infection, varicella-zoster virus (VZV) establishes latency in neurons of the dorsal root and trigeminal ganglia. Many questions concerning the mechanism of VZV pathogenesis remain unanswered, due in part to the strict host tropism and inconsistent availability of human tissue obtained from autopsies and abortions. The recent development of induced pluripotent stem (iPS) cells provides great potential for the study of many diseases. We previously generated human iPS cells from skin fibroblasts by introducing four reprogramming genes with non-integrating adenovirus. In this study, we developed a novel protocol to generate sensory neurons from iPS cells. Human iPS cells were exposed to small molecule inhibitors for 10 days, which efficiently converted pluripotent cells into neural progenitor cells (NPCs). The NPCs were then exposed for two weeks to growth factors required for their conversion to sensory neurons. The iPS cell-derived sensory neurons were characterized by immunocytochemistry, flow cytometry, RT-qPCR, and electrophysiology. After differentiation, approximately 80% of the total cell population expressed the neuron-specific protein, βIII-tubulin. Importantly, 15% of the total cell population co-expressed the markers Brn3a and peripherin, indicating that these cells are sensory neurons. These sensory neurons could be infected by both VZV and herpes simplex virus (HSV), a related alphaherpesvirus. Since limited neuronal populations are capable of supporting the entire VZV and HSV life cycles, our iPS-derived sensory neuron model may prove useful for studying alphaherpesvirus latency and reactivation.

To determine the type of cell(s) that contain latent varicella-zoster virus (VZV) DNA, we prepared pure populations of neurons and satellite cells from trigeminal ganglia of 18 humans who had previously had a VZV infection. VZV DNA was present in 34 of 2,226 neurons (1.5%) and in none of 20,700 satellite cells. There was an average of 4.7 (range of 2 to 9) copies of VZV DNA per latently infected neuron. Latent VZV DNA was primarily present in large neurons, whereas the size distribution of herpes simplex virus DNA was markedly different.Varicella-zoster virus (VZV) is present in a latent form in sensory ganglia of humans who have had a primary infection (varicella) with VZV (11). This is demonstrated by the reactivation of VZV in these individuals as herpes zoster and by the presence of VZV DNA and proteins in ganglia recovered at autopsy (2,3,5,9,10,12,13,15,16,19,20,(22)(23)(24)26). Different laboratories have ascribed the site of latency to either neurons (12-14, 18, 22) or perineuronal satellite cells (5, 26); some laboratories suggest that neurons are the primary site of latency together with a smaller proportion of satellite cells containing the VZV genome (16,20). The primary aim of the experiments described here was to determine the type of cell in trigeminal ganglia that harbors latent VZV and also to obtain data on the proportion of these cells that contain latent VZV. One reason why the site of VZV latency has remained an open question is that neurons and satellite-supporting cells are tightly associated in ganglia and the in situ methods used to locate VZV DNA did not clearly resolve the source of the hybridization signal. This resolution was easier for latent HSV because a strong hybridization signal to HSV facilitated its localization to the nucleus of the neuron. In contrast, the hybridization signal from VZV DNA is considerably weaker and dispersed over both nucleus and cytoplasm. While the hybridization methodology has improved, these considerations remain (21, 30). To reduce the ambiguities inherent in the in situ methods, we developed a procedure to separate cell types prior to analysis. The separation procedure has been verified with a study of HSV (1). This report presents data on the cellular localization of latent VZV, the frequency of latency, and the number of viral genomes present in latent cells.