TLR3/TRIF and MAVS Signaling Is Essential in Regulating Mucosal T Cell Responses during Rotavirus Infection.

The functions of the natural dsRNA sensors TLR3 (TRIF) and RIG-I (MAVS) are crucial during viral challenge and have not been accurately clarified in adaptive immune responses to rotavirus (RV) infection. In this study, we found that RV infection caused severe pathological damage to the small intestine of TLR3-/- and TRIF-/- mice. Our data found that dendritic cells from TLR3-/- and TRIF-/- mice had impaired Ag presentation to the RV and attenuated initiation of T cells upon viral infection. These attenuated functions resulted in impaired CD4+ T and CD8+ T function in mice lacking TLR3-TRIF signaling postinfection. Additionally, attenuated proliferative capacity of T cells from TLR3-/- and TRIF-/- mice was observed. Subsequently, we observed a significant reduction in the absolute number of memory T cells in the spleen and mesenteric lymph node (MLN) of TRIF-/- recipient mice following RV infection in a bone marrow chimeric model. Furthermore, there was reduced migration of type 2 classical dendritic cells from the intestine to MLNs after RV infection in TLR3-/- and TRIF-/- mice. Notably, RV infection resulted in attenuated killing of spleen and MLN tissues in TRIF-/- and MAVS-/- mice. Finally, we demonstrated that RV infection promoted apoptosis of CD8+ T cells in TRIF-/- and TLR3-/-MAVS-/- mice. Taken together, our findings highlight an important mechanism of TLR3 signaling through TRIF in mucosal T cell responses to RV and lay the foundation for the development of a novel vaccine.

CRISPR/Cas13a-based genome editing for establishing the detection method of H9N2 subtype avian influenza virus.

Avian influenza virus (AIV) subtype H9N2 has significantly threatened the poultry business in recent years by having become the predominant subtype in flocks of chickens, ducks, and pigeons. In addition, the public health aspects of H9N2 AIV pose a significant threat to humans. Early and rapid diagnosis of H9N2 AIV is therefore of great importance. In this study, a new method for the detection of H9N2 AIV based on fluorescence intensity was successfully established using CRISPR/Cas13a technology. The Cas13a protein was first expressed in a prokaryotic system and purified using nickel ion affinity chromatography, resulting in a high-purity Cas13a protein. The best RPA (recombinase polymerase amplification) primer pairs and crRNA were designed and screened, successfully constructing the detection of H9N2 AIV based on CRISPR/Cas13a technology. Optimal concentration of Cas13a and crRNA was determined to optimize the constructed assay. The sensitivity of the optimized detection system is excellent, with a minimum detection limit of 10° copies/µL and didn't react with other avian susceptible viruses, with excellent specificity. The detection method provides the basis for the field detection of the H9N2 AIV.

Numerical Simulation of Fracture Propagation during Temporary Plugging Staged Fracturing in Tight-Oil Horizontal Wells.

Fracture propagation with temporary plugging hydraulic fracturing in tight-oil reservoirs is simulated in this study. The research considers dynamic fluid redistribution, with stress differences among multiple fractures. The fracture morphology during temporary plugging staged fracturing (TPSF) is investigated by using a user-defined perforation element combined with a pore-pressure finite-element model. The precision of the integrated model is verified by using the standard finite-element approach. Then, case studies are presented to investigate the influence of cluster spacing, horizontal stress difference coefficients (SDC), injection rates, and barrier tensile strengths. The simulation results show that central cluster fractures are hampered by side-cluster fractures, while TPSF can alleviate the effect and lead to a more uniform propagation of all fractures. Stress interference weakens as cluster spacing increases, and propagation patterns are minimally influenced once spacing reaches 40 m. Higher injection rates can improve the injection pressure, enlarging fracture width, and potentially increasing the risk of fracture penetration. Barrier tensile strength and horizontal SDC can modify fracture geometries and determine the penetration behavior of multiple fractures.

The protective effect of intranasal immunization with influenza virus recombinant adenovirus vaccine on mucosal and systemic immune response.

Influenza virus is a kind of virus that poses several hazards of animal and human health. Therefore, it is important to develop an effective vaccine to prevent influenza. To this end we successfully packaged recombinant adenovirus rAd-NP-M2e-GFP expressing multiple copies of influenza virus conserved antigens NP and M2e and packaged empty vector adenovirus rAd-GFP. The effect of rAd-NP-M2e-GFP on the activation of dendritic cell (DC) in vitro and in vivo was detected by intranasal immunization. The results showed that rAd-NP-M2e-GFP promoted the activation of DC in vitro and in vivo. After the primary immunization and booster immunization of mice through the nasal immune way, the results showed that rAd-NP-M2e-GFP induced enhanced local mucosal-specific T cell responses, increased the content of SIgA in broncho alveolar lavage fluids (BALF) and triggered the differentiation of B cells in the germinal center. It is proved that rAd-NP-M2e-GFP can significantly elicit mucosal immunity and systemic immune response. In addition, rAd-NP-M2e-GFP could effectively protect mice after H1N1 influenza virus challenge. To lay the foundation and provide reference for further development of influenza virus mucosal vaccine in the future.

A new chart of hydraulic fracture height prediction based on fluid-solid coupling equations and rock fracture mechanics.

The conventional method to predict hydraulic fracture height depends on linear elastic mechanics, and the typical Gulrajani-Nolte chart fails to reflect fracture height when the net pressure in the fracture is too high. Based on fluid-solid coupling equations and rock fracture mechanics, a new chart is obtained by the ABAQUS extended finite-element method. Compared with the Gulrajani-Nolte chart, this new chart shows that longitudinal propagation of hydraulic fracture is still finite when the net pressure in the fracture is higher than in situ stress difference between reservoir and restraining barrier. The barrier has a significant shielding effect on the longitudinal propagation of hydraulic fracture, and there is a threshold for an injection rate of fracturing fluid to ensure hydraulic fracture propagates in the barrier. Fracture height decreases with the increase of in situ stress difference. When the ratio of net pressure to in situ stress difference is less than 0.56, the propagation of hydraulic fracture is completely restricted in the reservoir. Hydraulic fracturing parameters in Well Shen52 and Well Shen55 are optimized by using the new chart. Array acoustic wave logging shows that the actual fracture height is at an average error within 14.3% of the theoretical value, which proves the accuracy of the new chart for field application.