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Background: Bamboo mosaic virus (BaMV) and the Potato virus X (PVX) are members of the genus Potexvirus and have a single-stranded positive-sense RNA genome. The 3'-untranslated region (UTR) of the BaMV RNA genome was mapped structurally into ABC (a cloverleaf-like), D (a stem-loop), and E (pseudoknot) domains. The BaMV replicase complex that was isolated from the infected plants was able to recognize the 3' UTR of PVX RNA to initiate minus-strand RNA synthesis in vitro. Results: To investigate whether the 3' UTR of PVX RNA is also compatible with BaMV replicase in vivo, we constructed chimera mutants using a BaMV backbone containing the PVX 3' UTR, which was inserted in or used to replace the various domains in the 3' UTR of BaMV. None of the mutants, except for the mutant with the PVX 3' UTR inserted upstream of the BaMV 3' UTR, exhibited a detectable accumulation of viral RNA in Nicotiana benthamiana plants. The in vitro BaMV RdRp replication assay demonstrated that the RNA products were generated by the short RNA transcripts, which were derived from the chimera mutants to various extents. Furthermore, the Vmax/KM of the BaMV 3' UTR (rABCDE) was approximately three fold higher than rABCP, rP, and rDE in minus-strand RNA synthesis. These mutants failed to accumulate viral products in protoplasts and plants, but were adequately replicated in vitro. Conclusions: Among the various studied BaMV/PVX chimera mutants, the BaMV-S/PABCDE that contained non-interrupted BaMV 3' UTR was the only mutant that exhibited a wild-type level of viral product accumulation in protoplasts and plants. These results indicate that the continuity of the domains in the 3' UTR of BaMV RNA was not interrupted and the domains were not replaced with the 3' UTR of PVX RNA in vivo. [ABSTRACT FROM AUTHOR]

This paper aims to tease out the paths of grammaticalization of Southern Mm causative verbs, chhoa ..., kah ..., sai ..., kio ..., khit ... and thoo .... Their semantic extensions affect the interpretation of the pivotal construction which they all share. These causative verbs, at a light verb position, link two events which have leeway for reinterpretations. ..., ..., ..., and ... go from dynamic causative to stative causative. ... and ... are interpreted differently in different constructional types. As verbs of giving, they develop ditransitive construction, then permissive causative and finally passive. The lexical properties of these verbs endow the causative construction with new meanings. [ABSTRACT FROM AUTHOR]

Previous evidence has indicated that the P25 protein encoded by Potato virus X (PVX) inhibits either the assembly or function of the effector complexes in the RNA silencing-based antiviral defence system (Bayne et al., Cell-to-cell movement of Potato Potexvirus X is dependent on suppression of RNA silencing. Plant J. 44, 471–482). This finding prompted us to investigate the possibility that P25 targets the Argonaute (AGO) effector nuclease of RNA silencing. Co-immunoprecipitation and Western blot analysis indicated that there is a strong interaction between P25 and AGO1 of Arabidopsis when these proteins are transiently co-expressed in Nicotiana benthamiana. P25 also interacts with AGO1, AGO2, AGO3 and AGO4, but not with AGO5 and AGO9. As an effective suppressor, the amount of AGO1 accumulated in the presence of P25 was dramatically lower than that infiltrated with HcPro, but was restored when treated with a proteasome inhibitor MG132. These findings are consistent with the idea that RNA silencing is an antiviral defence mechanism and that the counter-defence role of P25 is through the degradation of AGO proteins via the proteasome pathway. Further support for this idea is provided by the observation that plants treated with MG132 are less susceptible to PVX and its relative Bamboo mosaic virus. [ABSTRACT FROM AUTHOR]

A 3′-terminal, 77-nucleotide sequence of Bamboo mosaic virus (BaMV) minus-strand RNA (Ba-77), comprising a 5′ stem-loop, a spacer and a 3′-CUUUU sequence, can be used to initiate plus-strand RNA synthesis in vitro. To understand the mechanism of plus-strand RNA synthesis, mutations were introduced in the 5′ untranslated region of BaMV RNA, resulting in changes at the 3′ end of minus-strand RNA. The results showed that at least three uridylate residues in 3′-CUUUU are required and the changes at the penultimate U are deleterious to viral accumulation in Nicotiana benthamiana protoplasts. Results from UV-crosslinking and in vitro RNA-dependent RNA polymerase competition assays suggested that the replicase preferentially interacts with the stem structure of Ba-77. Finally, CMV/83 + UUUUC, a heterologus RNA, which possesses about 80 nucleotides containing the 3′-CUUUU pentamer terminus, and which folds into a secondary structure similar to that of Ba-77, could be used as template for RNA production by the BaMV replicase complex in vitro. [ABSTRACT FROM AUTHOR]

Although immunodeficiency is usually considered a prerequisite of oncogenesis, a detailed immune profile in cancer has not yet been described. Without such profiling, it is not surprising that there is a vast discrepancy in the responses of cancer patients to immunotherapy. Our results show that the integrity of the immune system deteriorates with cancer progression by displaying a trend toward decreasing levels of functional T cells, including CD4, naïve, and central memory T cells, and an expansion of hyporesponsive populations such as CD28− and CMV-specific T cells. One hundred and one patients constitute the study group for the observational study reported in this paper. Forty-eight patients with newly diagnosed stages III and IV and 53 patients with extensively treated stage IV disease. The costimulatory molecules CD27 and CD28 were downregulated in all patients. Among the proinflammatory cytokines (IL-6, TNF-α, IFN-γ), only IL-6 differed significantly among the groups, increasing as the cancer stage progressed. Plasma IL-7 did not differ among the participants. The relative deficits of naïve T cells in cancer patients may be associated with the downregulation of IL-7Rα expression rather than changes in the circulating levels of IL-7. The downregulation of IL-7Rα expression was shown to be associated with increased levels of intracellular CMV. The present study suggests that the immune impairment in patients with cancer is associated with multiple factors, such as the stage of cancer, consequence of CMV infection and impact of treatment. [ABSTRACT FROM AUTHOR]

A biosensor for the detection of biological warfare agents (Bacillus anthracis spores) was developed that combines the phage display technique with a magnetoelastic wireless detection platform. The affinity-based biosensor utilizes a phage-derived diagnostic probe as the biomolecular recognition element to capture target agents multivalently. Upon binding of the target agent to the sensor surface, the resonance frequency of the magnetoelastic biosensors decreases due to the additional mass of the target agent. Scanning electron microscopy was used to confirm binding of spores to the sensor surface. The sensitivity of the magnetoelastic acoustic sensor was tested to be 130 Hz per order of magnitude of spore concentration with a detection limit of 103 spores/ml. The specificity of the sensors was tested against spores of other closely related Bacillus species and a large preferential binding to Bacillus anthracis spores was observed. The longevity of the phage based biosensor was compared to traditional antibody based biosensors and found to exhibit a much longer life [ABSTRACT FROM PUBLISHER]

A response by Yen-Ta Lu and his colleagues on their article "Immune Impairment in Patients With Terminal Cancers: Influence of Cancer Treatments and Cytomegalovirus Infection" which was published in the previous issue of the journal is presented.

Examines the effect of water deprivation and salt restriction on atrial natriuretic peptide (ANP) synthesis in the kidney and heart of rats. Increase of renal medullary ANP messenger RNA (mRNA); Reduction of cardiac atrial ANP mRNA; Findings on the plasma angiotensin II concentration.

Bamboo mosaic virus (BaMV) has a single-stranded positive-sense RNA genome. The secondary structure of the 3′-terminal sequence of the minus-strand RNA has been predicted by MFOLD and confirmed by enzymatic structural probing to consist of a large, stable stem-loop and a small, unstable stem-loop. To identify the promoter for plus-strand RNA synthesis in this region, transcripts of 39, 77, and 173 nucleotides (Ba-39, Ba-77, and Ba-173, respectively) derived from the 3′ terminus of the minus-strand RNA were examined by an in vitro RNA-dependent RNA polymerase assay for the ability to direct RNA synthesis. Ba-77 and Ba-39 appeared to direct the RNA synthesis efficiently, while Ba-173 failed. Ba-77/Δ 5, with a deletion of the 3′-terminal UUUUC sequence in Ba-77, directed the RNA synthesis only to 7% that of Ba-77. However, Ba-77/Δ 16 and Ba-77/Δ 31, with longer deletions but preserving the terminal UUUUC sequence of Ba-77, restored the template activity to about 60% that of the wild type. Moreover, mutations that changed the sequence in the stem of the large stem-loop interfered with the efficiency of RNA synthesis and RNA accumulation in vivo. The mutant with an internal deletion in the region between the terminal UUUUC sequence and the large stem-loop reduced the viral RNA accumulation in protoplasts, but mutants with insertions did not. Taken together, these results suggest that three cis-acting elements in the 3′ end of the minus-strand RNA, namely, the terminal UUUUC sequence, the sequence in the large stem-loop, and the distance between these two regions, are involved in modulating the efficiency of BaMV plus-strand viral RNA synthesis. [ABSTRACT FROM AUTHOR]