Epitope and Fc-Mediated Cross-linking, but Not High Affinity, Are Critical for Antitumor Activity of CD137 Agonist Antibody with Reduced Liver Toxicity
MOLECULAR CANCER THERAPEUTICS
Authors: Ho, Sun K.; Xu, Zhenghai; Thakur, Archana; Fox, Melvin; Tan, Siu Sze; DiGiammarino, Enrico; Zhou, Li; Sho, Mien; Cairns, Belinda; Zhao, Vivian; Xiong, Mengli; Samayoa, Josue; Forsyth, Charles M.; Powers, David B.; Chao, Debra T.; Hollenbaugh, Diane; Alvarez, Hamsell M.; Akamatsu, Yoshiko
Abstract
CD137 (TNFRSF9, 4-1BB) agonist antibodies ( mAb) have demonstrated potent antitumor activity with memory response while causing hepatotoxicity in mouse models. In clinical trials, the degrees of liver toxicity of anti-CD137 vary from grade 4 transaminitis (urelumab) to nonexistent (utomilumab). To exploit the antitumor potential of CD137 signaling, we identified a new class of CD137 agonist mAbs with strong antitumor potency without significant transaminitis in vivo compared with CD137 agonists previously reported. These mAbs are crossreactive to mouse and cynomolgus monkey and showed cross-linking-dependent T-cell costimulation activity in vitro. Antitu-mor efficacy was maintained in Fc gamma receptor (Fc gamma R) III-deficient mice but diminished in Fc gamma RIIB-deficient mice, suggesting the critical role for Fc gamma RIIB to provide cross-linking in vivo. Interestingly, a single dose of an affinity-reduced variant was sufficient to control tumor growth, but a higher affinity variant did not improve efficacy. These observations suggest that binding epitope and Fc gamma R interaction, but not necessarily high affinity, are important for antitumor efficacy and reduced liver toxicity of CD137 mAb. Our study suggests the possibility of CD137 agonist therapy with improved safety profile in humans.
Anti-inflammatory Effects of Extracts of Sweet Basil (Ocimum basilicum L.) on a Co-culture of 3T3-L1 Adipocytes and RAW264.7 Macrophages
JOURNAL OF OLEO SCIENCE
Authors: Takeuchi, Haruka; Takahashi-Muto, Chie; Nagase, Mana; Kassai, Masahiro; Tanaka-Yachi, Rieko; Kiyose, Chikako
Abstract
Obesity, a lifestyle disease resulting from excessive caloric intake and insufficient physical activity, results in a state of chronic inflammation. A food ingredient that suppresses chronic inflammation could help prevent associated diseases. Sweet basil (Ocimum basilicum L.) is a herb from the Lamiaceae family with some reported anti-inflammatory effects. Via this in vitro study, we aimed to investigate whether sweet basil exerts anti-inflammatory effects in obese patients. Fresh sweet basil leaves were freeze-dried and powered. After that, this was extracted with 80% methanol. After 3T3-L1 adipocytes were cultured with sweet basil extracts at final concentrations of either 5 or 25 mu g/mL for 24h, RAW264.7 macrophages were seeded onto this adipocytes and co-cultured for 12h. We determined the effects of sweet basil extracts on inflammatory cytokine expression by real-time PCR or western blotting. Sweet basil extracts reduced the expression of inflammatory cytokine mRNA induced by co-culture, including that of IL-6 (Il6), IL-1 beta (Il1b), TNF-alpha (Tnf), and CCL2 (Cc12). In addition, sweet basil extracts suppressed the mRNA expression of NF-kappa B (Nf kappa b1), a transcription factor of inflammatory cytokines. In an investigation of costimulatory CD137 (Tnfrsf9)/CD137L inflammatory signaling, a member of the TNF super-family, sweet basil extracts inhibited Tnfrsf9 expression induced by the co-culture. Therefore, the results of this study indicated that sweet basil extracts have an anti-inflammatory effect against adipocyte-induced inflammation, possibly through suppression of Tnfrsf9 expression.