Diabetes is a major risk factor for premature atherosclerosis, and oxidative stress appears to be an important mechanism. Previously, we showed that diabetic monocytes produce increased superoxide anion (O 2 ؊ ), and ␣-tocopherol (AT) supplementation decreases this. The aim of this study was to elucidate the mechanism (

OX40 is a costimulatory molecule that belongs to the tumor necrosis factor receptor (TNFR) superfamily. OX40 agonist‐based combinations are emerging as promising candidates for novel cancer immunotherapy. Clinical trials have shown that OX40 agonist antibodies could lead to better results in cancer patients. Using a hybridoma platform and three different types of immunization strategies, namely recombinant protein, DNA, and overexpressing cells, we identified a chimeric anti‐OX40 antibody (mAb035‐hIgG1 from DNA immunization) that shows excellent binding specificity, and slightly stronger activation of human memory CD4+ T cells and similar potent antitumor activity compared with BMS 986178, an anti‐OX40 antibody currently being evaluated for the treatment of solid tumors. This paper further systematically investigates the antigen‐specific immune response, the number of binders, epitope bins, and functional activities of antibodies among different immunization strategies. Interestingly, we found that different immunization strategies affect the biological activity of monoclonal antibodies.

CD137 (4‐1BB, TNFRSF9), an inducible T‐cell costimulatory receptor, is expressed on activated T cells, activated NK cells, Treg cells, and several innate immune cells, including DCs, monocytes, neutrophils, mast cells, and eosinophils. In animal models and clinical trials, anti‐CD137 agonistic monoclonal antibodies have shown anti‐tumor potential, but balancing the efficacy and toxicity of anti‐CD137 agonistic monoclonal antibodies is a considerable hindrance for clinical applications. Here, we describe a novel fully human CD137 agonistic antibody (PE0116) generated from immunized harbor H2L2 human transgenic mice. PE0116 is a ligand blocker, which is also the case for Utomilumab (one of the leading CD137 agonistic drugs); PE0116 partially overlaps with Urelumab's recognized epitope. In vitro, PE0116 activates NF‐κB signaling, significantly promotes T‐cell proliferation, and increases cytokine secretion in the presence of cross‐linking. Importantly, PE0116 possesses robust anti‐tumor activity in the MC38 tumor model. In vivo, PE0116 exhibits a good safety profile and has typical pharmacokinetic characteristics of an IgG antibody in preclinical studies of non‐human primates. In summary, PE0116 is a promising anti‐CD137 antibody with a good safety profile in preclinical studies.

Cluster of differentiation 47 (CD47) is a widely expressed self‐protection transmembrane protein that functions as a critical negative regulator to induce macrophage‐mediated phagocytosis. Overexpression of CD47 enables cancer cells to escape immune surveillance and destruction by phagocytes both in solid tumours and leukaemia. The usefulness of anti‐CD47 antibody has been demonstrated in multiple immunotherapies associated with macrophages. However, antigen sinks and toxicity induced by inadvertent binding to normal cells restrict its clinical applications. Here, a novel anti‐human CD47 antibody, 4D10, was generated, and its variable regions were grafted onto a human IgG4 scaffold. Compared with the anti‐CD47 antibody Hu5F9, the resulting chimeric antibody (c4D10) has consistently demonstrated good tolerance in in vitro and in vivo toxicity studies. Additionally, c4D10 showed effective therapeutic potential through inducing the eradication of human cancer cells. Thus, c4D10 is a promising candidate therapeutic antibody with higher efficacy and reduced side effects compared to earlier antibodies, and its use may reduce the dose‐limiting toxicity of CD47 antagonists for immunotherapy.

4-1BB is a member of the tumor necrosis factor superfamily and plays a critical role in activation of cytotoxic T cells to promote anti-tumor immunity. As a co-stimulatory molecule, it is ideally suited for activation via agonist therapeutic antibodies in order to reactivate the immune system and promote cytolytic activity through CD8+ T cells. Clinical trials of two agonist antibodies (Urelumab and Utomilumab) are ongoing. Urelumab has shown clinical efficacy but been hampered by inflammatory liver toxicity at doses above 1 mg/kg, suggesting potential safety concerns at higher doses. Utomilumab has a superior safety profile, but is a less potent 4-1BB agonist. Hence, it may be necessary to achieve potent immune activation while avoiding limiting immune-related adverse events. PE0116 is a fully human monoclonal antibody generated from immunization of Harbour H2L2 human transgenic mice with recombinant human 4-1BB protein. It blocks the binding of 4-1BB to its ligand 4-1BBL and its activity in T cell activation is crosslinking dependent. After crosslinking, PE0116 strongly increases IFNg secretion from T cells in the presence of anti-CD3 antibody and its activity is superior to Utomilumab analog. More importantly, PE0116 has demonstrated robust anti-tumor activity and better potency than both benchmark antibodies in MC38 tumor model with human 4-1BB KI mice. PE0116 has also demonstrated good safety profile in a non-GLP safety study in cyno monkey. Currently the antibody is under late stage IND-enabling study. Its safety and efficacy will be further tested in patients. Citation Format: Ningning Song, Zhengwu Li, Shan He, Teddy Yang, Qing Duan. Pre-clinical evaluation of PE0116: A potent cross-linking depednet 4-1BB agonist antibody [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2397.