Reactivation from latency displays HIV particle budding at plasma membrane, accompanying CD44 upregulation and recruitment

<p>Abstract</p> <p>Background</p> <p>It has been accepted that HIV buds from the cell surface in T lymphocytes, whereas in macrophages it buds into intracellular endosomes. Recent studies, on the other hand, suggest that HIV preferentially buds from the cell surface even in monocytic cells. However, most studies are based on observations in acutely infected cells and little is known about HIV budding concomitant with reactivation from latency. Such studies would provide a better understanding of a reservoir for HIV.</p> <p>Results</p> <p>We observed HIV budding in latently infected T lymphocytic and monocytic cell lines following TNF-α stimulation and examined the upregulation of host factors that may be involved in particle production. Electron microscopy analysis revealed that reactivation of latently infected J1.1 cells (latently infected Jurkat cells with HIV-1) and U1 cells (latently infected U937 cells with HIV-1) displayed HIV particle budding predominantly at the plasma membrane, a morphology that is similar to particle budding in acutely infected Jurkat and U937 cells. When mRNA expression levels were quantified by qRT-PCR, we found that particle production from reactivated J1.1 and U1 cells was accompanied by CD44 upregulation. This upregulation was similarly observed when Jurkat and U937 cells were acutely infected with HIV-1 but not when just stimulated with TNF-α, suggesting that CD44 upregulation was linked with HIV production but not with cell stimulation. The molecules in endocytic pathways such as CD63 and HRS were also upregulated when U1 cells were reactivated and U937 cells were acutely infected with HIV-1. Confocal microscopy revealed that these upregulated host molecules were recruited to and accumulated at the sites where mature particles were formed at the plasma membrane.</p> <p>Conclusion</p> <p>Our study indicates that HIV particles are budded at the plasma membrane upon reactivation from latency, a morphology that is similar to particle budding in acute infection. Our data also suggest that HIV expression may lead to the upregulation of certain host cell molecules that are recruited to sites of particle assembly, possibly coordinating particle production.</p

Regulation of hepatitis C virus secretion by the Hrs-dependent exosomal pathway

AbstractThe molecular mechanisms of assembly and budding of hepatitis C virus (HCV) remain poorly understood. The budding of several enveloped viruses requires an endosomal sorting complex required for transport (ESCRT), which is part of the cellular machinery used to form multivesicular bodies (MVBs). Here, we demonstrated that Hrs, an ESCRT-0 component, is critical for the budding of HCV through the exosomal secretion pathway. Hrs depletion caused reduced exosome production, which paralleled with the decrease of HCV replication in the host cell, and that in the culture supernatant. Sucrose-density gradient separation of the culture supernatant of HCV-infected cells revealed the co-existence of HCV core proteins and the exosome marker. Furthermore, both the core protein and an envelope protein of HCV were detected in the intraluminal vesicles of MVBs. These results suggested that HCV secretion from host cells requires Hrs-dependent exosomal pathway in which the viral assembly is also involved

Non-BAC Component but not Epidermal Growth Factor Receptor Gene Mutation is Associated with Poor Outcomes in Small Adenocarcinoma of the Lung

ObjectiveThe purpose of this study was to identify risk factors for poor clinical outcome after surgical resection of small lung adenocarcinoma.Materials and MethodsClinical records of 127 patients who had pathologic stage IA lung adenocarcinoma 20 mm or less and who had undergone a lobectomy with mediastinal lymph node dissection were reviewed. The percentage of non-bronchioloalveolar carcinoma (non-BAC) components quantified objectively, and epidermal growth factor receptor gene (EGFR) mutation determined by polymerase chain reaction-based assay were retrospectively linked with clinical data.ResultsBased on the percentage of non-BAC component, 127 patients were classified as follows: 26 in group I, BAC, 46 in group II mixed subtype with ≥ 50% BAC, 18 in group III, mixed subtype with under 50% BAC, and 37 in group IV, mixed subtype with all non-BAC components or a pure pattern of one of the non-BAC components. Groups I and II were considered to be a “low non-BAC component type” and groups III and IV were considered to be a “high non-BAC component type.” EGFR mutations in exon19 and exon21 were observed in 64 patients (50.4%). In terms of recurrence, the high non-BAC component type was the only independent factor for recurrence (p = 0.029). Regarding survival, the high age (p = 0.028) and high non-BAC component type (p = 0.046) were independent risk factors for poor overall survival. They were also independent risk factors for poor disease-free survival (p = 0.025 and p = 0.027, respectively).ConclusionThe high non-BAC component but not EGFR mutation status, is an independent risk factor for both recurrence and poor prognosis in patients with stage IA lung adenocarcinoma ≤20 mm

Effect of Peripheral 5-HT on Glucose and Lipid Metabolism in Wether Sheep

In mice, peripheral 5-HT induces an increase in the plasma concentrations of glucose, insulin and bile acids, and a decrease in plasma triglyceride, NEFA and cholesterol concentrations. However, given the unique characteristics of the metabolism of ruminants relative to monogastric animals, the physiological role of peripheral 5-HT on glucose and lipid metabolism in sheep remains to be established. Therefore, in this study, we investigated the effect of 5-HT on the circulating concentrations of metabolites and insulin using five 5-HT receptor (5HTR) antagonists in sheep. After fasting for 24 h, sheep were intravenously injected with 5-HT, following which-, plasma glucose, insulin, triglyceride and NEFA concentrations were significantly elevated. In contrast, 5-HT did not affect the plasma cholesterol concentration, and it induced a decrease in bile acid concentrations. Increases in plasma glucose and insulin concentrations induced by 5-HT were attenuated by pre-treatment with Methysergide, a 5HTR 1, 2 and 7 antagonist. Additionally, decreased plasma bile acid concentrations induced by 5-HT were blocked by pre-treatment with Ketanserin, a 5HTR 2A antagonist. However, none of the 5HTR antagonists inhibited the increase in plasma triglyceride and NEFA levels induced by 5-HT. On the other hand, mRNA expressions of 5HTR1D and 1E were observed in the liver, pancreas and skeletal muscle. These results suggest that there are a number of differences in the physiological functions of peripheral 5-HT with respect to lipid metabolism between mice and sheep, though its effect on glucose metabolism appears to be similar between these species

有限要素法を用いた中小病院の「Clean Hospital化」に関する実測および解析

In recent years, the increase of nosocomical infections caused by droplet infection, airborne infection or contact infection has been a social problem, and preventive countermeasures are being discussed. For SARS (Severe Acute Respiratory Syndrome) for example, it has been argued that the delay of action to prevent it has caused a global problem. For the purpose of seeking data concerning hospital sanitization, from the perspective of preventive medicine, this paper examined the real condition of a certain small-to-medium sized hospital for a year. Measurements focused on microbes (staphylococci and fungi), the most serious sources of infections in hospitals, including common bacteria (total count), staphylococcus , aureus, and multidrug-resistant staphylococcus aureus. We measured air cleanliness and airborne microbes at principal spots in the hospital 12 times during the year; after culturing, colony count was done to each microbe. Also, we measured the surface-adherent microbes taken from walls or fixtures (work tables, handrails, bed sheets, etc.) 6 times during the year. Multivariate analysis was done on the data. The results show the changes in the number of microbes depending on temperature and humidity throughout a 12-month period. Compared effects of different cleaning methods are also shown

Analysis of Morphology and Infectivity of Measles Virus Particles

The measles virus (MeV) shows polymorphisms in morphology and viral particle size, however, the localization of viral proteins and infectivity in viral particles of different sizes have not been well characterized. To determine the localization of viral proteins and the infectivity of viral particles of different sizes, MeV-infected cells and their culture supernatant were analyzed by electron microscopy and membrane filter fractionation. The sizes of MeV-like particles were distributed between 50 and 1000 nm and the major distribution peak was found for particles with diameters of 350-400 nm. The MeV M protein was lined under the envelope of all MeV-like particles and membrane-filter-fractionated MeVs of all sizes showed infectivity. These findings suggest that MeV particles, particularly large particles, can be used as a vaccine by designing a chimera virus containing antigens or genome of other virus species