A Novel Dual-Fc Bispecific Antibody with Enhanced Fc Effector Function.

Bispecific antibodies (BsAbs) are undergoing continued development for applications in oncology and autoimmune diseases. While increasing activity by having more than one targeting arm, most BsAb engineering employs single Fc engagement as monoclonal antibodies. Here, we designed a novel immunoglobulin gamma-1 (IgG1)-derived dual-Fc BsAb containing two Fc regions and two distinct asymmetric antigen binding arms comprising a Fab arm and another VHH domain. In conjunction with the knob-into-hole technology, dual-Fc BsAbs could be produced with a high yield and good stability. We explore how Fc engineering effects on dual-Fc constructs could boost the desired therapeutic efficacy. This new format enabled simultaneous bispecific binding to corresponding antigens. Furthermore, compared to the one-Fc control molecules, dual-Fc BsAbs were shown to increase the avidity-based binding to FcγRs to result in higher ADCC and ADCP activities by potent avidity via binding to two antigens and Fc receptors. Overall, this novel BsAb format with enhanced effector functionalities provides a new option for antibody-based immunotherapy.

Hederacoside C ameliorates colitis via restoring impaired intestinal barrier through moderating S100A9/MAPK and neutrophil recruitment inactivation.

Hederacoside C (HSC) has attracted much attention as a novel modulator of inflammation, but its anti-inflammatory mechanism remains elusive. In the present study, we investigated how HSC attenuated intestinal inflammation in vivo and in vitro. HSC injection significantly alleviated TNBS-induced colitis by inhibiting pro-inflammatory cytokine production and colonic epithelial cell apoptosis, and partially restored colonic epithelial cell proliferation. The therapeutic effect of HSC injection was comparable to that of oral administration of mesalazine (200 mg·kg-1·d-1, i.g.). In LPS-stimulated human intestinal epithelial Caco-2 cells, pretreatment with HSC (0.1, 1, 10 µM) significantly inhibited activation of MAPK/NF-κB and its downstream signaling pathways. Pretreatment with HSC prevented LPS-induced TLR4 dimerization and MyD88 recruitment in vitro. Quantitative proteomic analysis revealed that HSC injection regulated 18 proteins in the colon samples, mainly clustered in neutrophil degranulation. Among them, S100A9 involved in the degranulation of neutrophils was one of the most significantly down-regulated proteins. HSC suppressed the expression of S100A9 and its downstream genes including TLR4, MAPK, and NF-κB axes in colon. In Caco-2 cells, recombinant S100A9 protein activated the MAPK/NF-κB signaling pathway and induced inflammation, which were ameliorated by pretreatment with HSC. Notably, HSC attenuated neutrophil recruitment and degranulation as well as S100A9 release in vitro and in vivo. In addition, HSC promoted the expression of tight junction proteins and repaired the epithelial barrier via inhibiting S100A9. Our results verify that HSC ameliorates colitis via restoring impaired intestinal barrier through moderating S100A9/MAPK and neutrophil recruitment inactivation, suggesting that HSC is a promising therapeutic candidate for colitis.

Activation of spinal ephrin-B3/EphBs signaling induces hyperalgesia through a PLP-mediated mechanism.

Ephrin B/EphB signaling pathway is involved in the regulation of pain caused by spinal cord injury. However, the role of ephrin-B3/EphBs signaling in regulation of nociceptive information is poorly understood. In the present study, formalin-induced inflammatory pain, mechanical allodynia and thermal hyperalgesia, was measured using Efnb3 mutant mice (Efnb3-/- ) and wild-type (Efnb3+/+ ) mice. The spinal cord (L4-6) was selected for molecular and cellular identification by western blotting and immunofluorescence. Efnb3 mutant mice showed a significant increased the thermal and mechanical threshold, followed by aberrant thin myelin sheath. Furthermore, expression of proteolipid protein (PLP) was significantly lower in L4-6 spinal cord of Efnb3-/- mice. These morphological and behavioral abnormalities in mutant mice were rescued by conditional knock-in of wild-type ephrin-B3. Intrathecal administration of specific PLP siRNA significantly increased the thermal and mechanical threshold hyperalgesia in wild-type mice. However, overexpressing PLP protein by AAV9-PLP could decrease the sensitivity of mice to thermal and mechanical stimuli in Efnb3-/- mice, compared with scrabble Efnb3-/- mice. Further, Efnb3lacz mice, which have activities to initiate forward signaling, but transduce reverse signals by ephrin-B3, shows normal acute pain behavior, compared with wild type mice. These findings indicate that a key molecule Efnb3 act as a prominent contributor to hyperalgesia and essential roles of ephrin-B3/EphBs in nociception through a myelin-mediated mechanism.

Anemoside B4 ameliorates TNBS-induced colitis through S100A9/MAPK/NF-κB signaling pathway.

BACKGROUND: Despite the increased morbidity of ulcerative colitis (UC) in the developing countries, available treatments remain unsatisfactory. Therefore, it is urgent to discover more effective therapeutic strategies. Pulsatilla chinensis was widely used for the treatment of inflamed intestinal diseases including UC for thousands of years in China. Anemoside B4, the most abundant triterpenoid saponin isolated from P. chinensis, exerts anti-inflammatory and antioxidant effects and may be the most active compounds, which is responsible for the therapeutic effects. However, the mechanism how anemoside B4 executes its biological functions is still elusive. METHODS: Here, we used the 2, 4, 6-trinitrobenzene sulfonic acid (TNBS)-induced colitis rat model to evaluate the therapeutic effect of anemoside B4. Blood samples of colitis rats were collected for hematology analysis. The inflammation-associated factors were investigated by enzyme-linked immunosorbent assay (ELISA). Cell proliferation and apoptosis was determined with EdU cell proliferation assay and TUNEL assay. The proteins regulated by anemoside B4 were identified by label-free quantitative proteomics. The significantly down-regulated proteins were verified by Western blotting analysis. mRNA expression was analyzed by quantitative real-time RT-PCR. RESULTS: The results showed that anemoside B4 ameliorated TNBS-induced colitis symptoms, including tissue damage, inflammatory cell infiltration, and pro-inflammatory cytokine production, apoptosis and slowed proliferation in colon. Quantitative proteomic analyses discovered that 56 proteins were significantly altered by anemoside B4 in the TNBS-induced rats. These proteins mainly clustered in tricarboxylic acid (TCA) cycle and respiratory electron transport chain. Among the altered proteins, S100A9 is one of the most significantly down-regulated proteins and associated with NF-κB and MAPK signaling pathways in the pathogenesis of UC. Further experiments revealed that anemoside B4 suppressed the expression of S100A9 and its downstream genes including TLR4 and NF-κB in colon. In vitro, anemoside B4 could inhibit the NF-κB signaling pathway induced by recombinant S100A9 protein in human intestinal epithelial Caco-2 cells. Moreover, anemoside B4 inhibits neutrophils recruitment and activation in colon induced by TNBS. CONCLUSIONS: Our results demonstrate that anemoside B4 prevents TNBS-induced colitis by inhibiting the NF-κB signaling pathway through deactivating S100A9, suggesting that anemoside B4 is a promising therapeutic candidate for colitis.

Anticancer activity of oleiferoside B involving autophagy and apoptosis through increasing ROS release in MCF-7 cells and SMMC-7721 cells.

Oleiferoside B is a triterpenoid monomer compound, mainly isolated from roots of Camellia oleifera Abel, the underlying mechanism of its antitumour is not clear. In the present study, oleiferoside B potently inhibited SMMC-7721 and MCF-7 cells proliferation and cause cells apoptosis. In addition, it activated an autophagy-mediated cell death pathway, as indicated by the accumulated the ratio of LC3- II/LC3- I and inhibited apoptosis protein expression after pre-treatment with autophagy inhibitors 3-MA. Further studies showed that oleiferoside B-induced apoptosis and autophagy was attributed to ROS release. In vivo oleiferoside B (1.0, 0.5 mg/kg) effectively suppressed tumour growth. In conclusion, our finding reveals a novel mechanism of action of oleiferoside B in cancer cells via induction of apoptosis and autophagy through ROS generation. Therefore, our results provided new insight into the mechanism of the antitumour effect of oleiferoside B as a prospective therapeutic drug in the tumour.

Anemoside B4 attenuates nephrotoxicity of cisplatin without reducing anti-tumor activity of cisplatin.

BACKGROUND: Cisplatin is a highly effective chemotherapeutic agent commonly used in the treatment of a wide variety of malignancies. However, its clinical usage is severely limited by its serious side effects, especially nephrotoxicity. Anemoside B4, is a major saponins, rich in root of Pulsatilla chinensis (Bunge), has anti-inflammation in vitro. However, the antioxidant or anti-inflammatory effects of anemoside B4 in cisplatin-induced nephrotoxicity have not been clearly demonstrated. PURPOSE: In this study, we investigated whether anemoside B4 exhibits protective effects against cisplatin-induced nephrotoxicity involving antioxidant or anti-apoptosis effects. METHOD: To clarify it, the effects of anemoside B4 on HEK 293 cell viability was measured by CCK8 kits, intracellular antioxidant capacity including glutathione reduced (GSH), catalase (CAT) were estimated using chemical kits, apoptosis rate and intracellular reactive oxygen species (ROS) was analyzed by flow cytometry, apoptosis protein was measured by western blotting. In vivo model of cisplatin-induced mice acute renal failure was performed to evaluate the properties of anemoside B4. Besides, to evaluate the effect of anemoside B4 on the anti-tumor activity of cisplatin, S180 xenograft models were used. RESULTS: Anemoside B4 potently increased cisplatin-treated HEK 293T cells viability on the concentration and time manners and inhibited cells apoptosis, as demonstrated by the decreased cleaved PARP protein expressions. Anemoside B4 decreased reactive oxygen species (ROS) content and improved superoxide dismutase (SOD) activity. In vivo experiment showed that pretreatment with anemoside B4 effectively adjusted body weight and kidney index, and reduced cisplatin-elevated blood urea nitrogen (BUN) and creatinine (CREA) levels, as well as ameliorated the histopathological damage. Further studies showed that anemoside B4 did not reduce antitumor activity of cisplatin in murine S180 cancer xenograft tumor models. In addition, anemoside B4 per set showed low toxicity in mice. CONCLUSION: The strong antioxidant and anti-apoptosis effects of anemoside B4 may provide therapeutic potential for cisplatin-induced nephrotoxicity without compromising its therapeutic efficiency.