Type I interferon receptor-independent and -dependent host transcriptional responses to mouse hepatitis coronavirus infection in vivo

<p>Abstract</p> <p>Background</p> <p>The role of type I IFNs in protecting against coronavirus (CoV) infections is not fully understood. While CoVs are poor inducers of type I IFNs in tissue culture, several studies have demonstrated the importance of the type I IFN response in controlling MHV infection in animals. The protective effectors against MHV infection are, however, still unknown.</p> <p>Results</p> <p>In order to get more insight into the antiviral gene expression induced in the brains of MHV-infected mice, we performed whole-genome expression profiling. Three different mouse strains, differing in their susceptibility to infection with MHV, were used. In BALB/c mice, which display high viral loads but are able to control the infection, 57 and 121 genes were significantly differentially expressed (≥ 1.5 fold change) upon infection at 2 and 5 days post infection, respectively. Functional association network analyses demonstrated a strong type I IFN response, with Irf1 and Irf7 as the central players. At 5 days post infection, a type II IFN response also becomes apparent. Both the type I and II IFN response, which were more pronounced in mice with a higher viral load, were not observed in 129SvEv mice, which are much less susceptible to infection with MHV. 129SvEv mice lacking the type I interferon receptor (IFNAR-/-), however, were not able to control the infection. Gene expression profiling of these mice identified type I IFN-independent responses to infection, with IFN-γ as the central player. As the BALB/c and the IFNAR-/- 129SvEv mice demonstrated very similar viral loads in their brains, we also compared their gene expression profiles upon infection with MHV in order to identify type I IFN-dependent transcriptional responses. Many known IFN-inducible genes were detected, several of which have previously been shown to play an important protective role against virus infections. We speculate that the additional type I IFN-dependent genes that we discovered may also be important for protection against MHV infection.</p> <p>Conclusion</p> <p>Transcriptional profiling of mice infected with MHV demonstrated the induction of a robust IFN response, which correlated with the viral load. Profiling of IFNAR-/- mice allowed us to identify type I IFN-independent and -dependent responses. Overall, this study broadens our present knowledge of the type I and II IFN-mediated effector responses during CoV infection <it>in vivo</it>.</p

Improved microarray gene expression profiling of virus-infected cells after removal of viral RNA

<p>Abstract</p> <p>Background</p> <p>Sensitivity and accuracy are key points when using microarrays to detect alterations in gene expression under different conditions. Critical to the acquisition of reliable results is the preparation of the RNA. In the field of virology, when analyzing the host cell's reaction to infection, the often high representation of viral RNA (vRNA) within total RNA preparations from infected cells is likely to interfere with microarray analysis. Yet, this effect has not been investigated despite the many reports that describe gene expression profiling of virus-infected cells using microarrays.</p> <p>Results</p> <p>In this study we used coronaviruses as a model to show that vRNA indeed interferes with microarray analysis, decreasing both sensitivity and accuracy. We also demonstrate that the removal of vRNA from total RNA samples, by means of virus-specific oligonucleotide capturing, significantly reduced the number of false-positive hits and increased the sensitivity of the method as tested on different array platforms.</p> <p>Conclusion</p> <p>We therefore recommend the specific removal of vRNA, or of any other abundant 'contaminating' RNAs, from total RNA samples to improve the quality and reliability of microarray analyses.</p

Gradual adaptation of animal influenza A viruses to human-type sialic acid receptors

Influenza A viruses (IAVs) originating from animal reservoirs pose continuous threats to human health as demonstrated by the Spanish flu pandemic. Infection starts by attachment to host receptors, a crucial step that is targeted by immunological, prophylactic, and therapeutic intervention. Fine-tuning of virus hemagglutinin binding to host-specific receptor repertoires needs to remain balanced to receptor-destroying neuraminidase (NA) activity and is a key step in host adaptation. It determines NA-dependent virus motility, enabling IAVs to traverse the mucus layer and to bind to, and migrate over, the epithelial cell surface for reaching a location supporting endocytic uptake. Canonical adaptations in enzootic/zoonotic IAVs enhancing human-type receptor binding are well-known, but the context and timespan required for their selection pose many questions. We discuss recent developments, focusing on the dynamic nature of interactions of IAV with the heterogeneous receptor repertoires present in humans and potential intermediate hosts. Potential pre-adaption toward human-type receptor binding in intermediate hosts will be discussed

A Non-relativistic Logarithmic Conformal Field Theory from a Holographic Point of View

We study a fourth-order derivative scalar field configuration in a fixed Lifshitz background. Using an auxiliary field we rewrite the equations of motion as two coupled second order equations. We specialize to the limit that the mass of the scalar field degenerates with that of the auxiliary field and show that logarithmic modes appear. Using non-relativistic holographic methods we calculate the two-point correlation functions of the boundary operators in this limit and find evidence for a non-relativistic logarithmic conformal field theory at the boundary.Comment: 17 pages, v2 : refs. adde

Detailed Kinetics of the Direct Allo-Response in Human Liver Transplant Recipients: New Insights from an Optimized Assay

Conventional assays for quantification of allo-reactive T-cell precursor frequencies (PF) are relatively insensitive. We present a robust assay for quantification of PF of T-cells with direct donor-specificity, and establish the kinetics of circulating donor-specific T cells after liver transplantation (LTx). B cells from donor splenocytes were differentiated into professional antigen-presenting cells by CD40-engagement (CD40-B cells). CFSE-labelled PBMC from LTx-recipients obtained before and at several time points after LTx, were stimulated with donor-derived or 3rd party CD40-B cells. PF of donor-specific T cells were calculated from CFSE-dilution patterns, and intracellular IFN-γ was determined after re-stimulation with CD40-B cells. Compared to splenocytes, stimulations with CD40-B cells resulted in 3 to 5-fold higher responding T-cell PF. Memory and naïve T-cell subsets responded equally to allogeneic CD40-B cell stimulation. Donor-specific CD4+ and CD8+ T-cell PF ranged from 0.5 to 19% (median: 5.2%). One week after LTx, PF of circulating donor-specific CD4+ and CD8+ T cells increased significantly, while only a minor increase in numbers of T cells reacting to 3rd party allo-antigens was observed. One year after LTx numbers of CD4+ and CD8+ T cells reacting to donor antigens, as well as those reacting to 3rd party allo-antigens, were slightly lower compared to pre-transplant values. Moreover, CD4+ and CD8+ T cells responding to donor-derived, as well as those reacting to 3rd party CD40-B cells, produced less IFN-γ. In conclusion, our alternative approach enables detection of allo-reactive human T cells at high frequencies, and after application we conclude that donor-specific T-cell PF increase immediately after LTx. However, no evidence for a specific loss of circulating T-cells recognizing donor allo-antigens via the direct pathway up to 1 year after LTx was obtained, underscoring the relative insensitiveness of previous assays

RadioImmunotherapy for adenoid cystic carcinoma: a single-institution series of combined treatment with cetuximab

<p>Abstract</p> <p>Background</p> <p>Local control in adjuvant/definitive RT of adenoid cystic carcinoma (ACC) is largely dose-dependent. However, some clinical situations do not allow application of tumouricidal doses (i.e. re-irradiation) hence radiation sensitization by exploitation of high endothelial growth factor receptor (EGFR)-expression in ACC seems beneficial. This is a single-institution experience of combined radioimmunotherapy (RIT) with the EGFR-inhibitor cetuximab.</p> <p>Methods</p> <p>Between 2006 and 2010, 9 pts received RIT for advanced/recurrent ACC, 5/9 pts as re-irradiation. Baseline characteristics as well as treatment parameters were retrieved to evaluate efficacy and toxicity of the combination regimen were evaluated. Control rates (local/distant) and overall survival were calculated using Kaplan-Meier estimation.</p> <p>Results</p> <p>Median dose was 65 Gy, pts received a median of 6 cycles cetuximab. RIT was tolerated well with only one °III mucositis/dysphagia. Overall response/remission rates were high (77,8%); 2-year estimate of local control was 80% hence reaching local control levels comparable to high-dose RT. Progression-free survival (PFS) at 2 years and median overall survival were only 62,5% and 22,2 mo respectively.</p> <p>Conclusion</p> <p>While local control and treatment response in RIT seems promising, PFS and overall survival are still hampered by distant failure. The potential benefit of RIT with cetuximab warrants exploration in a prospective controlled clinical trial.</p

Palliative chemotherapy or best supportive care? A prospective study explaining patients' treatment preference and choice

Item does not contain fulltextIn palliative cancer treatment, the choice between palliative chemotherapy and best supportive care may be difficult. In the decision-making process, giving information as well as patients' values and preferences become important issues. Patients, however, may have a treatment preference before they even meet their medical oncologist. An insight into the patient's decision-making process can support clinicians having to inform their patients. Patients (n=207) with metastatic cancer, aged 18 years or older, able to speak Dutch, for whom palliative chemotherapy was a treatment option, were eligible for the study. We assessed the following before they consulted their medical oncologist: (1) socio-demographic characteristics, (2) disease-related variables, (3) quality-of-life indices, (4) attitudes and (5) preferences for treatment, information and participation in decision-making. The actual treatment decision, assessed after it had been made, was the main study outcome. Of 207 eligible patients, 140 patients (68%) participated in the study. At baseline, 68% preferred to undergo chemotherapy rather than wait watchfully. Eventually, 78% chose chemotherapy. Treatment preference (odds ratio (OR)=10.3, confidence interval (CI) 2.8-38.0) and a deferring style of decision-making (OR=4.9, CI 1.4-17.2) best predicted the actual treatment choice. Treatment preference (total explained variance=38.2%) was predicted, in turn, by patients' striving for length of life (29.5%), less striving for quality of life (6.1%) and experienced control over the cause of disease (2.6%). Patients' actual treatment choice was most strongly predicted by their preconsultation treatment preference. Since treatment preference is positively explained by striving for length of life, and negatively by striving for quality of life, it is questionable whether the purpose of palliative treatment is made clear. This, paradoxically, emphasises the need for further attention to the process of information giving and shared decision-making

Movement of environmental threats modifies the relevance of the defensive eye-blink in a spatially-tuned manner.

Subcortical reflexive motor responses are under continuous cortical control to produce the most effective behaviour. For example, the excitability of brainstem circuitry subserving the defensive hand-blink reflex (HBR), a response elicited by intense somatosensory stimuli to the wrist, depends on a number of properties of the eliciting stimulus. These include face-hand proximity, which has allowed the description of an HBR response field around the face (commonly referred to as a defensive peripersonal space, DPPS), as well as stimulus movement and probability of stimulus occurrence. However, the effect of stimulus-independent movements of objects in the environment has not been explored. Here we used virtual reality to test whether and how the HBR-derived DPPS is affected by the presence and movement of threatening objects in the environment. In two experiments conducted on 40 healthy volunteers, we observed that threatening arrows flying towards the participant result in DPPS expansion, an effect directionally-tuned towards the source of the arrows. These results indicate that the excitability of brainstem circuitry subserving the HBR is continuously adjusted, taking into account the movement of environmental objects. Such adjustments fit in a framework where the relevance of defensive actions is continually evaluated, to maximise their survival value