Neutrophil depletion attenuates antibody-mediated rejection in a renal transplantation mouse model.

Antibody-mediated rejection (AMR) can cause graft failure following renal transplantation. Neutrophils play a key role in AMR progression, but the exact mechanism remains unclear. We investigated the effect of neutrophils on AMR in a mouse kidney transplantation model. The mice were divided into five groups: syngeneic transplantation (Syn), allograft transplantation (Allo), and three differently treated AMR groups. The AMR mouse model was established using skin grafts to pre-sensitize recipient mice. Based on the AMR model, Ly6G-specific monoclonal antibodies were administered to deplete neutrophils (NEUT-/- + AMR) and TACI-Fc was used to block B-cell-activating factor (BAFF)/a proliferation-inducing ligand (APRIL) signaling (TACI-Fc + AMR). Pathological changes were assessed using hematoxylin-eosin and immunohistochemical staining. Banff values were evaluated using the Banff 2015 criteria. Donor-specific antibody (DSA) levels were assessed using flow cytometry, and BAFF and APRIL concentrations were measured using ELISA. Compared to the Syn and Allo groups, a significantly increased number of neutrophils and increased C4d and IgG deposition were observed in AMR mice, accompanied by elevated DSA levels. Neutrophil depletion inhibited inflammatory cell infiltration and reduced C4d and IgG deposition. Neutrophil depletion significantly decreased DSA levels after transplantation and suppressed BAFF and APRIL concentrations, suggesting a mechanism for attenuating AMR-induced graft damage. Similar results were obtained after blockading BAFF/APRIL using a TACI-Fc fusion protein. In summary, neutrophil infiltration increased in the AMR mouse renal transplantation model. Neutrophil depletion or blockading the BAFF/APRIL signaling pathway significantly alleviated AMR and may provide better options for the clinical treatment of AMR.

Effects of Biofuel Crop Switchgrass (Panicum virgatum) Cultivation on Soil Carbon Sequestration and Greenhouse Gas Emissions: A Review.

Under the macroenvironmental background of global warming, all countries are working to limit climate change. Internationally, biofuel plants are considered to have great potential in carbon neutralization. Several countries have begun using biofuel crops as energy sources to neutralize carbon emissions. Switchgrass (Panicum virgatum) is considered a resource-efficient low-input crop that produces bioenergy. In this paper, we reviewed the effects of switchgrass cultivation on carbon sequestration and greenhouse gas (GHG) emissions. Moreover, the future application and research of switchgrass are discussed and prospected. Switchgrass has huge aboveground and underground biomass, manifesting its huge carbon sequestration potential. The net change of soil surface 30 cm soil organic carbon in 15 years is predicted to be 6.49 Mg ha-1, significantly higher than that of other crops. In addition, its net ecosystem CO2 exchange is about -485 to -118 g C m-2 yr-1, which greatly affects the annual CO2 flux of the cultivation environment. Nitrogen (N) fertilizer is the main source of N2O emission in the switchgrass field. Nitrogen addition increases the yield of switchgrass and also increases the N2O flux of switchgrass soil. It is necessary to formulate the most appropriate N fertilizer application strategy. CH4 emissions are also an important indicator of carbon debt. The effects of switchgrass cultivation on CH4 emissions may be significant but are often ignored. Future studies on GHG emissions by switchgrass should also focus on CH4. In conclusion, as a biofuel crop, switchgrass can well balance the effects of climate change. It is necessary to conduct studies of switchgrass globally with the long-term dimension of climate change effects.