Applying antibody-sensitive hypervariable region 1-deleted hepatitis C virus to the study of escape pathways of neutralizing human monoclonal antibody AR5A

Hepatitis C virus (HCV) is a major cause of end-stage liver diseases. With 3-4 million new HCV infections yearly, a vaccine is urgently needed. A better understanding of virus escape from neutralizing antibodies and their corresponding epitopes are important for this effort. However, for viral isolates with high antibody resistance, or antibodies with moderate potency, it remains challenging to induce escape mutations in vitro. Here, as proof-of-concept, we used antibody-sensitive HVR1-deleted (ΔHVR1) viruses to generate escape mutants for a human monoclonal antibody, AR5A, targeting a rare cross-genotype conserved epitope. By analyzing the genotype 1a envelope proteins (E1/E2) of recovered Core-NS2 recombinant H77/JFH1ΔHVR1 and performing reverse genetic studies we found that resistance to AR5A was caused by substitution L665W, also conferring resistance to the parental H77/JFH1. The mutation did not induce viral fitness loss, but abrogated AR5A binding to HCV particles and intracellular E1/E2 complexes. Culturing J6/JFH1ΔHVR1 (genotype 2a), for which fitness was decreased by L665W, with AR5A generated AR5A-resistant viruses with the substitutions I345V, L665S, and S680T, which we introduced into J6/JFH1 and J6/JFH1ΔHVR1. I345V increased fitness but had no effect on AR5A resistance. L665S impaired fitness and decreased AR5A sensitivity, while S680T combined with L665S compensated for fitness loss and decreased AR5A sensitivity even further. Interestingly, S680T alone had no fitness effect but sensitized the virus to AR5A. Of note, H77/JFH1L665S was non-viable. The resistance mutations did not affect cell-to-cell spread or E1/E2 interactions. Finally, introducing L665W, identified in genotype 1, into genotypes 2-6 parental and HVR1-deleted variants (not available for genotype 4a) we observed diverse effects on viral fitness and a universally pronounced reduction in AR5A sensitivity. Thus, we were able to take advantage of the neutralization-sensitive HVR1-deleted viruses to rapidly generate escape viruses aiding our understanding of the divergent escape pathways used by HCV to evade AR5A

Differential cholinergic activation of G proteins in rat and mouse brainstem: Relevance for sleep and nociception

Murine models are increasingly used for investigations of sleep, yet no previous studies have characterized cholinergic activation of guanine nucleotide binding proteins (G proteins) in mouse brainstem nuclei known to regulate sleep. This study used in vitro [ 35 S]guanylyl-5′- O -(Γ-thio)-triphosphate ([ 35 S]GTPΓS) autoradiography to test the hypothesis that muscarinic cholinergic receptors activate G proteins in C57BL/6J (B6) mouse brainstem. The nuclei studied are homologous to those known in rat and cat to modulate sleep and nociception. In B6 mouse, carbachol significantly increased specific binding of [ 35 S]GTPΓS in the pontine reticular nucleus, caudal part (79%); pontine reticular nucleus, oral part (131%); laterodorsal tegmental nucleus (56%); pedunculopontine tegmental nucleus (86%); dorsal raphe nucleus (53%); dorsal medial periaqueductal gray (54%); and ventrolateral periaqueductal gray (52%) when compared with basal binding. Carbachol-induced G protein activation was concentration-dependent and blocked by atropine, demonstrating mediation by muscarinic receptors. G protein activation by carbachol was heterogeneous across B6 mouse brainstem nuclei. Comparison of [ 35 S]GTPΓS binding between mouse and rat revealed different magnitudes of G protein activation in the pontine reticular formation. In the same pontine reticular formation area of B6 mouse where in vitro treatment with carbachol activates G proteins, in vivo microinjection of cholinomimetics causes a rapid eye movement sleep-like state. These data provide the first direct measurement of muscarinic receptor-activated G proteins in B6 mouse brainstem nuclei known in other species to regulate sleep. J. Comp. Neurol. 457:175–184, 2003. © 2003 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/34467/1/10548_ftp.pd

Zoonosis, cambio climático y sociedad

La sociedad contemporánea se enfrenta a uno de los retos más grandes de la historia humana, el calentamiento global, mismo que acarrea enormes consecuencias, tales como los disturbios climáticos, así como los patrones de las enfermedades de origen animal transmisibles al hombre. Precisamente ante este escenario las instituciones educativas de nivel superior deben dar cumplimiento a su responsabilidad y ser las generadoras de alternativas de solución mediante el trabajo especializado de investigación; y para ello, la pesquisa científica es la mejor de las alternativas a nuestro alcance para comprender y encarar estos desafíos.Universidad Autónoma del Estado de México y Ediciones y Gráficos Eón, S.A. de C.V

Obesity in the Liver Transplant Setting

The obesity epidemic has resulted in an increased prevalence of obesity in liver transplant (LT) candidates and in non-alcoholic fatty liver disease (NAFLD) becoming the fastest growing indication for LT. LT teams will be dealing with obesity in the coming years, and it is necessary for them to recognize some key aspects surrounding the LT in obese patients. Obesity by itself should not be considered a contraindication for LT, but it should make LT teams pay special attention to cardiovascular risk assessment, in order to properly select candidates for LT. Obese patients may be at increased risk of perioperative respiratory and infectious complications, and it is necessary to establish preventive strategies. Data on patient and graft survival after LT are controversial and scarce, especially for long-term outcomes, but morbid obesity may adversely affect these outcomes, particularly in NAFLD. The backbone of obesity treatment should be diet and exercise, whilst being careful not to precipitate or worsen frailty and sarcopenia. Bariatric surgery is an alternative for treatment of obesity, and the ideal timing regarding LT is still unknown. Sleeve gastrectomy is probably the procedure that has the best evidence in LT because it offers a good balance between safety and efficacy

Beyond the borders: The gates and fences of Neuroimmune interaction

Neuroimmunology is a rapidly growing emerging field at which two old sciences have converged to integrate two different types of responses into a single coherent response involving the coordinated action of both systems, neural and immune. During long time it was thought that both systems worked separately and in divergent pathways. The brain was considered an immunoprivileged site and the immune organs were deemed as independent of any neural influence and also of nervous innervation. Time has gone and has proven that the borders between both systems were merely artificial. Since the beginning of Neuroimmunology in the 1980s much work has been done to elucidate the gates and fences in neuro-immune interactions. Brain was shown to be under the continuous surveillance of the immune system, even under basal physiological conditions in the absence of any pathology. Likely, it was found a profuse nervous innervation of lymphoid organs and even of single immune cells. Gates for direct neural immune communication were found both centrally and peripherally. Centrally, the gates, but also the fences, were situated at the brain barriers, the blood-brain barrier and the blood-cerebrospinal fluid barrier, and at the circunventricular organs. Peripherally, the fences constituted the apparent diverse nature of molecules involved in neural and immune signaling; however, time proved that both system were capable of producing the same signaling molecules and also systematically responded to the molecules released by the other system. Therefore, the gates were open for direct neural-immune communication at the peripheral level. This Research Topic aimed to include original reports, reviews and technical reports regarding the description of the gates and fences in neural immune interactions. We intended to provide an extensive view of the mechanisms governing central and peripheral neural-immune interactions, and the role of the borders, the blood-neural barriers, in the regulation of the neural-immune communication

Management of concomitant hepatocellular carcinoma and chronic hepatitis C: a review

Our comprehensive review focuses on the treatment of hepatitis C virus in the context of hepatocellular carcinoma and vice versa, highlighting the ongoing complexity of this clinical scenario. There remain multiple unanswered questions when considering the management of these complex patients and, with a rapidly-changing treatment landscape for both chronic hepatitis C and hepatocellular carcinoma, these questions are only going to grow. Treatment timing, interactions and the impact of one disease condition on the other are vitally important, though guidance generally remains non-specific, suggesting that we make these decisions on a case-by-case basis. We focus on the current evidence for managing these cases, depending on disease stage and treatment type