Project description:CD137 cis-costimulation is superior to trans-costimulation at inducing transcriptomic differences in T-cell proliferation and DNA repair programs We used microarrays to detail differentially expressed genes of cis- and trans CD137-costimulated CD8 T cells with respect to CD3-TCR stimulation
Project description:The cell surface glycoprotein CD137, which is also known as 4-1BB, belongs to the group of co-stimulatory immune receptors and is a member of the TNF receptor superfamily (TNFRSF). It is preferentially found on activated T-cells and regulatory T-cells. In T-cells, CD137-crosslinking delivers a potent co-stimulatory signal as it promotes T-cell proliferation, formation of memory cells and enhances survival. Despite numerous studies investigating the effects of co-stimulatory CD137 in T-cells, little is known regarding the role of CD137 in human monocytes/macrophages. To investigate the effect of CD137 triggering on human monocytes, monocytes were isolated and treated with an agonistic CD137 mAb and subsequently analyzed by RNA-seq.
Project description:We report the differences of gene expression pattern of tumor-infiltrating CD8 T cells between CD137 expressing cells and CD137 non-expressing cells in human metastatic ovarian cancer. Samples are obtained from 3 ovarian cancer patients, and we sorted CD137 expressing cells and CD137 non-expressing cells in CD39 expressing CD8 T cells for RNA sequencing. We found that even though the CD39 expression and PD-1 expression levels are similar, CD137 expressing cells showed more activated and less exhausted phenotypes than CD137 non-expressing cells.
Project description:CD137 (4-1BB) is a member of the TNFR superfamily that represents a promising target for cancer immunotherapy. Recent insights into the function of TNFR agonist antibodies implicate epitope, affinity, and IgG subclass as critical features, and these observations help explain the limited activity and toxicity seen with clinically tested CD137 agonists. Here we describe the preclinical characterization of CTX-471, a fully human IgG4 agonist of CD137 that engages a unique epitope that is shared by human, cynomolgus monkey, and mouse and is associated with a differentiated pharmacology and toxicology profile. In vitro, CTX-471 increased IFN-γ production by human T cells in an FcγR-dependent manner, displaying an intermediate level of activity between two clinical-stage anti-CD137 antibodies. In mice, CTX-471 exhibited curative monotherapy activity in various syngeneic tumor models and showed a unique ability to cure mice of very large (~500 mm3) tumors compared to validated antibodies against checkpoints and TNFR superfamily members. Extremely high doses of CTX-471 were well-tolerated, with no signs of hepatic toxicity. Collectively, these data demonstrate that CTX-471 is a unique CD137 agonist that display an excellent safety profile and an unprecedented level of monotherapy efficacy against very large tumors.
Project description:Rationale: Bone is the most common metastatic site of breast cancer. CD137(4-1BB), a member of the tumor necrosis factor (TNF) receptor superfamily, is mainly expressed in activated leukocytes. Previous study demonstrates the effect of CD137-CD137L bidirectional signaling pathway on RANKL-mediated osteoclastogenesis. However, the role of CD137 in bone metastasis of breast cancer needs further study. Methods: Stable monocyte/macrophage cell lines with Cd137 overexpression and silencing were established. Western blot, real-time PCR, transwell and tartrate-resistant acid phosphatase staining were used to detect the regulatory effect of CD137 on migration and osteoclastogenesis of monocytes/macrophages in vitro. Spontaneous bone metastasis mouse model was established, bioluminescent images, immunohistochemistry and histology assay were performed to detect the function of CD137 in bone metastasis in vivo. Results: We found that CD137 promotes the migration of monocytes/macrophages to tumor microenvironment by upregulating the expression of Fra1. It also promoted the differentiation of monocytes/macrophages into osteoclasts at the same time, thus providing a favorable microenvironment for the colonization and growth of breast cancer cells in bone. Based on these findings, a novel F4/80-targeted liposomal nanoparticle encapsulating the anti-CD137 Ab blocking antibody (NP-aCD137 Ab-F4/80) was synthesized. This nanoparticle could inhibit both bone and lung metastases of 4T1 breast cancer cells with high efficacy in vivo. In addition, it increased the therapeutic efficacy of Fra1 inhibitor on tumor metastasis. Conclusions: Taken together, these findings reveal the promotion effect of macrophage/monocyte CD137 on bone metastases and provide a promising therapeutic strategy for metastasis of breast cancer.
Project description:CD137 is a costimulatory receptor expressed on natural killer cells, T cells, and subsets of dendritic cells. An agonistic monoclonal antibody (mAb) against CD137 has been used to reduce tumor burden or reverse autoimmunity in animal models and clinical trials. When testing the ability of agonistic anti-CD137 mAb to promote clearance of persistent virus infection, we recently reported reduced numbers of germinal center B (GC B) cells and follicular dendritic cells (FDC) in lymphoid tissues. Here, we show that agonistic anti-CD137 agonistic mAb treatment impairs antibody responses with multiple T cell-dependent antigens including virus infection, recombinant viral antigens, and conjugated haptens but not with a T cell-independent antigen or at homeostasis. These effects were not due to enhanced apoptosis or impaired proliferation of B cells but instead correlated with disorganization of the stromal cell compartment of the GC, and were mediated by CD137 signaling in CD4+ and CD8+ T cells. Anti-CD137 treatment in the context of acute infection also resulted in reduced numbers of marginal zone B cells, greater numbers of antibody-secreting plasmablasts, and pro-inflammatory signatures in several myeloid and lymphoid cell populations of the spleen. Our experiments in mice suggest that agonistic anti-CD137 mAbs used in cancer and autoimmunity therapy may alter stromal cell populations to causes GC collapse and impaired long-term antibody and B cell memory responses.