BACKGROUND: Glucocorticoid-induced TNFR-related protein (TNFRSF18, GITR, CD357), expressed by T cells, and its ligand (TNFSF18, GITRL), expressed by myeloid populations, provide co-stimulatory signals that boost T cell activity. Due to the important role that GITR plays in regulating immune functions, agonistic stimulation of GITR is a promising therapeutic concept. Multiple strategies to induce GITR signaling have been investigated. The limited clinical efficacy of antibody-based GITR agonists results from structural and functional characteristics of antibodies that are unsuitable for stimulating the well-defined trimeric members of the TNFRSF. METHODS: To overcome limitations of antibody-based TNFRSF agonists, we have developed HERA-GITRL, a fully human hexavalent TNF receptor agonist (HERA) targeting GITR and mimicking the natural signaling concept. HERA-GITRL is composed of a trivalent but single-chain GITRL-receptor-binding-domain (scGITRL-RBD) unit fused to an IgG1 derived silenced Fc-domain serving as dimerization scaffold. A specific mouse surrogate, mmHERA-GITRL, was also generated to examine in vivo activity in respective mouse tumor models. RESULTS: For functional characterization of HERA-GITRL in vitro, human immune cells were isolated from healthy-donor blood and stimulated with anti-CD3 antibody in the presence of HERA-GITRL. Consistently, HERA-GITRL increased the activity of T cells, including proliferation and differentiation, even in the presence of regulatory T cells. In line with these findings, mmHERA-GITRL enhanced antigen-specific clonal expansion of both CD4+ (OT-II) and CD8+ (OT-I) T cells in vivo while having no effect on non-specific T cells. In addition, mmHERA-GITRL showed single-agent anti-tumor activity in two subcutaneous syngeneic colon cancer models (CT26wt and MC38-CEA). Importantly, this activity is independent of its FcγR-binding functionality, as both mmHERA-GITRL with a functional Fc- and a silenced Fc-domain showed similar tumor growth inhibition. Finally, in a direct in vitro comparison to a bivalent clinical benchmark anti-GITR antibody and a trivalent GITRL, only the hexavalent HERA-GITRL showed full biological activity independent of additional crosslinking. CONCLUSION: In this manuscript, we describe the development of HERA-GITRL, a true GITR agonist with a clearly defined mechanism of action. By clustering six receptor chains in a spatially well-defined manner, HERA-GITRL induces potent agonistic activity without being dependent on additional FcγR-mediated crosslinking.
- MeSH
- aktivace lymfocytů MeSH
- imunoglobuliny - Fc fragmenty imunologie MeSH
- jednořetězcové protilátky aplikace a dávkování imunologie MeSH
- lidé MeSH
- Macaca fascicularis MeSH
- myši MeSH
- nádorové buněčné linie MeSH
- receptory TNF agonisté MeSH
- regulační T-lymfocyty imunologie MeSH
- rekombinantní fúzní proteiny imunologie MeSH
- signální transdukce MeSH
- tumor nekrotizující faktory chemie metabolismus MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Intestinal homeostasis is precisely regulated by a number of endogenous regulatory molecules but significantly influenced by dietary compounds. Malfunction of this system may result in chronic inflammation and cancer. Dietary essential n-3 polyunsaturated fatty acids (PUFAs) and short-chain fatty acid butyrate produced from fibre display anti-inflammatory and anticancer activities. Both compounds were shown to modulate the production and activities of TNF family cytokines. Cytokines from the TNF family (TNF- α, TRAIL, and FasL) have potent inflammatory activities and can also regulate apoptosis, which plays an important role in cancer development. The results of our own research showed enhancement of apoptosis in colon cancer cells by a combination of either docosahexaenoic acid (DHA) or butyrate with TNF family cytokines, especially by promotion of the mitochondrial apoptotic pathway and modulation of NF κ B activity. This review is focused mainly on the interaction of dietary PUFAs and butyrate with these cytokines during colon inflammation and cancer development. We summarised recent knowledge about the cellular and molecular mechanisms involved in such effects and outcomes for intestinal cell behaviour and pathologies. Finally, the possible application for the prevention and therapy of colon inflammation and cancer is also outlined.
- MeSH
- apoptóza MeSH
- butyráty metabolismus MeSH
- cytokiny metabolismus MeSH
- dieta MeSH
- kolon patologie MeSH
- kyseliny dokosahexaenové metabolismus MeSH
- lidé MeSH
- mitochondrie patologie MeSH
- myši MeSH
- nádory metabolismus MeSH
- nenasycené mastné kyseliny metabolismus MeSH
- NF-kappa B metabolismus MeSH
- střeva metabolismus MeSH
- tumor nekrotizující faktory metabolismus MeSH
- zánět metabolismus MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
- MeSH
- antirevmatika farmakologie škodlivé účinky terapeutické užití MeSH
- etanercept MeSH
- imunosupresiva farmakologie škodlivé účinky terapeutické užití MeSH
- infliximab MeSH
- inhibitory TNF MeSH
- leflunomid MeSH
- methotrexát farmakologie škodlivé účinky terapeutické užití MeSH
- revmatoidní artritida farmakoterapie MeSH
- tumor nekrotizující faktory metabolismus MeSH
- Publikační typ
- přehledy MeSH
- Geografické názvy
- Spojené státy americké MeSH
- MeSH
- antirevmatika aplikace a dávkování farmakologie terapeutické užití MeSH
- inhibitory cyklooxygenasy metabolismus terapeutické užití MeSH
- juvenilní artritida dějiny farmakoterapie MeSH
- kombinovaná farmakoterapie MeSH
- kyselina arachidonová metabolismus terapeutické užití MeSH
- tumor nekrotizující faktory metabolismus terapeutické užití MeSH
- Publikační typ
- přehledy MeSH
- MeSH
- adjuvancia imunologická farmakologie MeSH
- antivirové látky farmakologie MeSH
- cytokiny metabolismus MeSH
- lipopolysacharidy farmakologie MeSH
- myši MeSH
- nukleosidy farmakologie MeSH
- oxid dusnatý metabolismus MeSH
- tumor nekrotizující faktory metabolismus MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
