Characteristics of changes in double positive CD4+CD8+ T cells in liver transplantation.

Although double positive CD4+CD8+ T (DPT) cells has been reported to be involved in some diseases, their trajectory and function as associated with liver transplantation (LT) remain unclear. In the present study, we found that the number of DPT cells was increased in the blood and liver tissue of LT patients. Meanwhile, we compared the distribution of DPT cells in peripheral blood samples and in penetrating liver tissue between liver rejection versus non-rejection patients, as well as the proportion of DPT cells as a function of the extent of liver rejection. The number of DPT cells in the rejection group was significantly increased. An analysis of the spatial distance and correlations between DPT and Treg cells, revealed that these cells showed a high degree of contiguity. In a mouse liver transplant model, the number of DPT cells were significantly increased in liver tissue, and the number of CD8+ T cells gradually increased, while CD4+ T cells decreased as a function of time post-transplantation. Expression level of PD-1 in DPT cells also increased in a temporally-dependent manner post liver transplantation and the changes of PD-1+ DPT cells were related to the degree of liver transplant rejection. In DPT cells interacting with Treg, there was an increased expression of PD-1, which enhanced cellular exhaustion. In conclusion, the capacity for DPT cells to induce immune tolerance may represent a new and important protocol for use in targeting treatments for the prevention of liver transplant rejection.

Liver injury in COVID-19: Detection, pathogenesis, and treatment.

In the early December 2019, a novel coronavirus named severe acute respiratory syndrome coronavirus 2 was first reported in Wuhan, China, followed by an outbreak that spread around the world. Numerous studies have shown that liver injury is common in patients with coronavirus disease 2019 (COVID-19), and may aggravate the severity of the disease. However, the exact cause and specific mechanism of COVID-associated liver injury needs to be elucidated further. In this review, we present an analysis of the clinical features, potential mechanisms, and treatment strategies for liver injury associated with COVID-19. We hope that this review would benefit clinicians in devising better strategies for management of such patients.

Influence of sodium dodecyl sulfate coating on adsorption of methylene blue by biochar from aqueous solution.

Biochar is regarded as a promising new class of materials due to its multifunctional character and the possibility of effectively coupling different properties. With increasing introduction into the environment, environmental chemicals such as surfactants will load onto the released biochar and change its physicochemical characteristics and adsorption behavior toward pollutants. In this study, sodium dodecyl sulfate (SDS), as one type of anionic surfactant, was coated onto biochar with different loading amounts. The influence of SDS loading onto biochar's physicochemical properties were investigated by Fourier transform infrared (FT-IR) spectroscopy, elemental analysis, zeta potential and Brunauer-Emmett-Teller (BET) surface area and pore size distribution analysis. Results showed that the pore size of the biochar decreased gradually with the increase of SDS loading because of the surface-adsorption and pore-blocking processes; the pH of the point of zero charge (pHPZC) decreased with increasing SDS loading. Although surface-coating with SDS decreased the pore size of the biochar, its adsorption capacity toward Methylene Blue (MB) significantly increased. The biochar-bound SDS introduced functional groups and negative charges to the biochar surface, which could thus enhance the adsorption of MB via hydrogen bonding and electrostatic interaction. The results can shed light on the underlying mechanism of the influence of anionic surfactants on the adsorption of MB by biochar.

Strong Expression of Recombinant Human Morphogenetic Protein-4 in Escherichia coli and its Bioassay in vivo / 中国生物工程杂志

Objective:To produce rhBMP-4 with bioactivity in E.coli. Methods: The full-length human BMP-4 gene was mutated by PCR without changes in amino acid sequence, then the synthesized gene was cloned into plasmid pET-3c, transducted into BL21(DE)plysS, and induced by adding IPTG to a final concentration of 1.0 mmol/L. The protein product was purified using ion-exchange chromatography method and then renaturated, bioactivity was checked by C2C12 differentiation in vitro and mouse ectopic bone formation in vivo. Results: A 438 bp gene fragment encoding mature peptide of hBMP-4 was cloned , the protein product was mostly in the form of inclusion body, after renaturation, the engineering protein shows better bioactivity. Conclusion:The mutant strategy can enhance the expression of bioactive rhBMP-4 in E.coli expression system.