Enhanced Apoptosis and Tumor Regression Induced by a Direct Agonist Antibody to Tumor Necrosis Factor–Related Apoptosis-Inducing Ligand Receptor 2

Abstract

Purpose: Substantial evidence indicates that supraoligomerization of the death receptors for Fas ligand and tumor necrosis factor^related apoptosis-inducing ligand (TRAIL) is necessary for efficient activationof the apoptoticpathway. Bivalent IgGantibodies caninduce the efficient apoptosis by mimicking the natural ligands but only after these antibodies are further oligomerized by crosslinking. In this study, we generated a novel agonist antibody to TRAIL receptor 2 (TRAIL-R2) capable of inducing apoptosis without cross-linking and elucidated its mode of action and efficacy. Experimental Design: A fully human antibody toTRAIL-R2, KMTR2, was generated from KM Mouse immunized with TRAIL-R2 ectodomain. Apoptosis-inducing activities of unfractionated or purified monomeric IgG of KMTR2 was evaluated in the presence or absence of cross-linkers, secondary antibodies or Fc receptor^expressing effector cells, against human colorectal adenocarcinoma Colo205. Oligomerization ofTRAIL-R2 was analyzed by size exclusion chromatography and confocal microscopy, and in vivo efficacy was examined in Colo205 xenograft model. Results: KMTR2 specifically recognized TRAIL-R2 and induced apoptosis with or without cross-linking. Size exclusion chromatography showed that the apoptosis activity coeluted with monomeric IgG and was effective independent of secondary antibody or Fc receptor^expressing effector cells. The antibody formed supracomplexes with soluble recombinant and membraneanchored TRAIL-R2 and enhanced clustering of TRAIL-R2 on cell surface without cross-linking. KMTR2 was dramatically efficacious in reducing established human tumor. Conclusion: Our findings indicate that novel agonist antibody KMTR2 can direct antibodydependent oligomerization of TRAIL-R2 and initiates efficient apoptotic signaling and tumor regression independent of host effector function. Thus, the direct agonist would be a lead candidate for cancer therapeutics.

Tissue Prognostic Factors in Melanoma: Expression of B7 Family Members B7-H3 and B7-H4 and Death Receptors TRAIL-R1 and TRAILR2

“…Another hypothesis is that a part of the TRAIL-R2 expression is related to the T lymphocytes of the microenvironment with induction by tumor cells of apoptosis of these T lymphocytes in a similar manner than PDL1 expression by the melanoma cells induces an apoptosis of PDL1+ lymphocytes. Our results support the ongoing development of therapeutic agents specifically targeting TRAIL receptors or TRAIL agonists [34,35]. The main weakness of our work it that in vivo we cannot eliminate the fact that the increased expression of these 3 proteins is partially related to other cells in the tumor micro environment.…”

The Design and Characterization of Receptor-selective APRIL Variants

“…Directed evolution methods employing phage display were also used to generate receptorselective TRAIL variants (37), a receptor-selective TNF␣ antagonist (38), and a LIGHT/LT␤ variant that does not bind DcR3 (39). In addition, selective receptor activation can also be achieved by the use of receptor-specific agonistic antibodies (40,41) or other binding scaffolds (42). Although these approaches can be equally useful, factors such as stoichiometry of receptor activation (40) and prolonged activation due to a longer half-life must be taken into account.…”

p53-Mediated upregulation of DcR1 impairs oxaliplatin/TRAIL-induced synergistic anti-tumour potential in colon cancer cells

“…These findings might be particularly relevant to ongoing clinical trials aiming at evaluating the anti-tumoural properties of TRAIL combined with chemotherapy. Alternatively, patients exhibiting wild-type p53 tumours could benefit from ongoing phases I-II clinical trials using either agonistic anti-DR4 or anti-DR5 Oxaliplatin/TRAIL combination in colon cancer F Toscano et al antibodies in human colon cancers (Motoki et al, 2005;Pukac et al, 2005;Mita et al, 2006). We have demonstrated recently that an agonistic antibody targeting DR5 in vitro could trigger apoptosis in cells expressing the corresponding agonistic receptor even when cells harbour either of the antagonistic receptors, DcR1 or DcR2, at their cell surface (Merino et al, 2006).…”