Relationship between the loss of neutralizing antibody binding and fusion activity of the F protein of human respiratory syncytial virus

To elucidate the relationship between resistance to HRSV neutralizing antibodies directed against the F protein and the fusion activity of the F protein, a recombinant approach was used to generate a panel of mutations in the major antigenic sites of the F protein. These mutant proteins were assayed for neutralizing mAb binding (ch101F, palivizumab, and MAb19), level of expression, post-translational processing, cell surface expression, and fusion activity. Functional analysis of the fusion activity of the panel of mutations revealed that the fusion activity of the F protein is tolerant to multiple changes in the site II and IV/V/VI region in contrast with the somewhat limited spectrum of changes in the F protein identified from the isolation of HRSV neutralizing antibody virus escape mutants. This finding suggests that aspects other than fusion activity may limit the spectrum of changes tolerated within the F protein that are selected for by neutralizing antibodies

Selectivity of Monaural Synaptic Inputs Underlying Binaural Auditory Information Integration in the Central Nucleus of Inferior Colliculus

Neurons in the central nucleus of the inferior colliculus (ICC) receive ascending inputs from the ipsilateral and contralateral auditory pathway. However, the contributions of excitatory or inhibitory synaptic inputs evoked by ipsilateral and contralateral stimuli to auditory responses of ICC neurons remain unclear. Using in vivo whole-cell voltage-clamp recordings, we investigated excitatory and inhibitory synaptic currents in neurons of the ICC in response to binaural stimulation by performing an intensity-intensity scan. To systematically analyze the contribution of the ipsilateral and contralateral ear, the sound intensity was randomly delivered to each side from 0 dB sound pressure level (SPL) to 70 dB SPL. Although the synaptic responses were dominated by contralateral inputs at weak sound intensities, they could be increased (or decreased) by additional ipsilateral stimulation at higher intensities. Interestingly, the synaptic responses to contralateral acoustic inputs were not linearly superimposed with the ipsilateral ones. By contrast, the responses showed either a contralateral or ipsilateral profile, depending on which one was more dominant. This change occurred at a certain intensity “switch” point. Thus, the binaural auditory responses of the ICC neurons were not simply mediated by the summation of the inputs evoked by ipsilateral and contralateral stimulations. This suggested that the ICC might inherit the acoustic information integrated at the brainstem, causing the selectivity of monaural excitation and inhibition to underlie the neuronal binaural acoustic response

Contribution of cysteine residues in the extracellular domain of the F protein of human respiratory syncytial virus to its function

The mature F protein of all known isolates of human respiratory syncytial virus (HRSV) contains fifteen absolutely conserved cysteine (C) residues that are highly conserved among the F proteins of other pneumoviruses as well as the paramyxoviruses. To explore the contribution of the cysteines in the extracellular domain to the fusion activity of HRSV F protein, each cysteine was changed to serine. Mutation of cysteines 37, 313, 322, 333, 343, 358, 367, 393, 416, and 439 abolished or greatly reduced cell surface expression suggesting these residues are critical for proper protein folding and transport to the cell surface. As expected, the fusion activity of these mutations was greatly reduced or abolished. Mutation of cysteine residues 212, 382, and 422 had little to no effect upon cell surface expression or fusion activity at 32°C, 37°C, or 39.5°C. Mutation of C37 and C69 in the F2 subunit either abolished or reduced cell surface expression by 75% respectively. None of the mutations displayed a temperature sensitive phenotype

Cloning, Characterization, and Functional Expression of Phospholipase D α

Phospholipase D (PLD) plays a key role in adaptive responses of postharvest fruits. A cDNA clone of banana (Musa acuminate L.) PLDα (MaPLDα) was obtained by RT-PCR in this study. The MaPLDα gene contains a complete open reading frame (ORF) encoding a 92-kDa protein composed of 832 amino acid residues and possesses a characteristic C2 domain and two catalytic H×K×××D (abbr. HKD) motifs. The two HKD motifs are separated by 341 amino acid residues in the primary structure. Relatively higher PLD activity and expression of MaPLDα mRNA were detected in developing tissues compared to senescent or mature tissues in individual leaves, flower, stem, and fruit organs, respectively. The expression profile of PLDα mRNA in postharvest banana fruits at different temperatures was determined, and the MaPLDα mRNA reached the highest expression peak on day 5 at 25°C and on day 7 at 12°C. The results provide useful information for maintaining postharvest quality and extending the storage life of banana fruit

Benefit of Relaxation-Type Damping on the Performance of a Six-Degree-of-Freedom Microvibration Isolation Device for Control Moment Gyroscope

In order to provide an ultraquiet environment for spacecraft payload, a six-degree-of-freedom microvibration isolation device for satellite control moment gyro (CMG) is proposed in this paper. The dynamic characteristics of the microvibration isolation device are analyzed theoretically and experimentally. The dynamic equations of the microvibration suppression device are established by using the Newton–Euler method. The dynamic responses are numerically solved and the frequency-domain characteristics of the microvibration isolation device under base excitation are analyzed. The analytical results are first verified numerically, and the two results are in good accordance. The experimental apparatus is built, and the vibration isolation performance is investigated. The acceleration transfer function is measured and the influence of the excitation amplitude on the vibration isolation performance is performed. It is shown that the amplification factor at the vicinity of the resonance frequency is within 10 dB, and the vibration isolation performance is significant at higher frequencies. The vibration attenuation performance at the main frequency of the CMG (100 Hz) is more than 30 dB. The microvibration suppression device can effectively suppress the microvibration generated by CMG during orbital operation

Comparative Transcriptomic Profiling in Ovarian Tissues of Lohmann Hens and Chengkou Mountain Chicken

Background: As a crucial economic characteristic and a major indicator of reproductive performance in layers, egg production is controlled by a series of complex regulatory heredity basis. In particular, the interacting regulatory function between noncoding RNAs (ncRNAs) and coding RNA plays important roles in regulating laying performance. Methods: In this study, the RNA sequencing (RNA-seq) of ovarian tissues from Lohmann hens (n = 3) and Chengkou Mountain chicken (n = 3) under the laying peak period was performed to identify RNA transcriptional differences among different laying-performance populations. Results: Results showed that the expression level of 303 mRNAs, 68 long ncRNAs (lncRNAs), 533 circular RNAs (circRNAs), and 79 microRNAs (miRNAs) was significantly different among the groups. Functional enrichment analysis of these differentially expressed (DE) mRNAs revealed that the laying process was implicated in numerous significantly enriched pathways (p < 0.05), such as the neuroactive ligand-receptor interaction, steroid hormone biosynthesis, and calcium-signaling pathway. Furthermore, the lncRNA/circRNA–miRNA–mRNA regulatory networks related to the regulation of laying performance were constructed. Some randomly selective DE RNAs were verified by Real Time Quantitative (RT-qRCR), indicating that the bioinformatics analysis results of RNA-seq data were credible. Conclusions: This study could increase our understanding of the heredity basis of transcriptome in the laying performance of chicken