Data_Sheet_1_Immune cell early activation, apoptotic kinetic, and T-cell functional impairment in domestic pigs after ASFV CADC_HN09 strain infection.docx

African swine fever (ASF) caused by the African swine fever virus (ASFV) is a fatal and highly contagious disease of domestic pigs characterized by rapid disease progression and death within 2 weeks. How the immune cells respond to acute ASFV infection and contribute to the immunopathogenesis of ASFV has not been completely understood. In this study, we examined the activation, apoptosis, and functional changes of distinct immune cells in domestic pigs following acute infection with the ASFV CADC_HN09 strain using multicolor flow cytometry. We found that ASFV infection induced broad apoptosis of DCs, monocytes, neutrophils, and lymphocytes in the peripheral blood of pigs over time. The expression of MHC class II molecule (SLA-DR/DQ) on monocytes and conventional DCs as well as CD21 expression on B cells were downregulated after ASFV infection, implying a potential impairment of antigen presentation and humoral response. Further examination of CD69 and ex vivo expression of IFN-γ on immune cells showed that T cells were transiently activated and expressed IFN-γ as early as 5 days post-infection. However, the capability of T cells to produce cytokines was significantly impaired in the infected pigs when stimulated with mitogen. These results suggest that the adaptive cellular immunity to ASFV might be initiated but later overridden by ASFV-induced immunosuppression. Our study clarified the cell types that were affected by ASFV infection and contributed to lymphopenia, improving our understanding of the immunopathogenesis of ASFV.</p

Synthesis and Characterization of an Injectable and Hydrophilous Expandable Bone Cement Based on Poly(methyl methacrylate)

Poly­(methyl methacrylate) (PMMA), the most common bone cement, has been used as a graft substitute in orthopedic surgeries such as vertebroplasty. However, an undesirable minor crack in the bone–cement interface provoked by shrinkage during polymerization and high elastic modulus of conventional PMMA bone cement dramatically increases the risk of vertebral body refracture postsurgery. Thus, herein, a hydrophilous expandable bone cement was synthesized based on a PMMA commercial cement (Mendec Spine Resin), acrylic acid (AA), and styrene (St). The two synthesized cements (PMMA-PAA, PMMA-PAA-PSt) showed excellent volumetric swelling in vitro and cohesive bone–cement contact in rabbit femur cavity defect. The elastic modulus and compressive strength of the new cements were lower than PMMA. Furthermore, the in vitro analysis indicated that the new cements had lower cytotoxicity than PMMA, including superior proliferation and lower apoptotic rates of Sprague–Dawly rat-derived osteoblasts. Western blotting for protein expression and RT-PCR analysis of osteogenesis-specific genes were conducted on SD rat-derived osteoblasts from both PMMA and new cements films; the results showed that new cements enhanced the expression of osteogenesis-specific genes. Scanning electron microscopy demonstrated improved morphology and attachment of osteoblast on new cement discs compared to the PMMA discs. Additionally, the histological morphologies of the bone–cement interface from the rabbit medial femoral condyle cavity defect model revealed direct and cohesive contact with the bone in the new cement groups in contrast to a minor crack in the PMMA cement group. The sign of a new bone growing into the cement has been found in the new cements after 12 weeks, thereby indicating the osteogenic capacity in vivo. In conclusion, the synthesized hydrophilous expandable bone cements based on PMMA and poly­(acrylic acid) (PAA) are promising candidates for vertebroplasty