Project description:Epigenetic alterations are common in both B cell and T cell lymphomas. These contribute to lymphomagenesis and treatment resistance, hence epigenetic therapy is being investigated. We evaluated the effects of the DNA-methyltrasferase inhibitor hydralazine and the histone deacetylase inhibitor valproate in T-cell lymphoma HuT78 cells and B-cell lymphoma Raji cells.
Project description:Adoptive T-cell therapy or oncolytic virotherapy has made significant progress, but the efficacy was limited by the lack of infiltration into solid tumors when used alone. Here, an oncolytic virus (rVSV-LCMVG) was designed and combined with adoptively transferred T cells. By turning cold tumors hot, in B16 tumor-bearing mice, combination therapy showed superior antitumor effects than monotherapy, whether rVSV-LCMVG was administered intratumorally or intravenously. Combination therapy significantly increased cytokine and chemokine levels within tumors and sensitized refractory tumors by boosting T-cell recruitment, down-regulating the expression of PD1, and restoring effector-T cell function. To offer a combination therapy with greater translational value, mRNA vaccines were introduced to induce tumor-specific T cells instead of adoptively transferred T cells, and exhibited comparable amplified anti-tumor effects. This study proposed a rational combination therapy of oncolytic virus with adoptive T-cell transfer or mRNA vaccines encoding tumor-associated antigens, in terms of synergistic efficacy and mechanism.
Project description:Adoptive T-cell therapy or oncolytic virotherapy has made significant progress, but the efficacy was limited by the lack of infiltration into solid tumors when used alone. Here, an oncolytic virus (rVSV-LCMVG) was designed and combined with adoptively transferred T cells. By turning cold tumors hot, in B16 tumor-bearing mice, combination therapy showed superior antitumor effects than monotherapy, whether rVSV-LCMVG was administered intratumorally or intravenously. Combination therapy significantly increased cytokine and chemokine levels within tumors and sensitized refractory tumors by boosting T-cell recruitment, down-regulating the expression of PD1, and restoring effector-T cell function. To offer a combination therapy with greater translational value, mRNA vaccines were introduced to induce tumor-specific T cells instead of adoptively transferred T cells, and exhibited comparable amplified anti-tumor effects. This study proposed a rational combination therapy of oncolytic virus with adoptive T-cell transfer or mRNA vaccines encoding tumor-associated antigens, in terms of synergistic efficacy and mechanism.
Project description:Purpose: Despite recent advances in the treatment of patients with aggressive lymphomas, still a significant fraction of patients will succumb to their disease. Thus, novel therapeutic strategies are urgently needed. As the anti-CD20 antibody rituximab and the CD19-targeting antibody tafasitamab share distinct modes of actions, we investigated if dual-targeting of aggressive lymphoma B-cells by combining rituximab and tafasitamab might increase cytotoxic effects. Experimental Design: Antibody single and combination efficacy was determined investigating different modes of action including direct cytotoxicity, antibody-dependent cell-mediated cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP) in vitro and in vivo models of aggressive B-cell lymphoma comprising diffuse large B-cell lymphoma (DLBCL) and Burkitt lymphoma (BL). Results: Overall, three different sensitivity profiles to antibody monotherapy or combination treatment were observed in in vitro models: while 2/11 cell lines were primarily sensitive to tafasitamab and 2/11 were predominantly sensitive to rituximab treatment, the combination of tafasitamab and rituximab resulted in enhanced cell death in 7/11 cell lines in at least one mode of action. Treatment with either antibody or the combination resulted in decreased expression of the oncogenic transcription factor MYC and inhibition of AKT signaling which mirrored the cell line-specific sensitivities to direct cytotoxicity. At last, the combinatorial approach of the two antibodies resulted in a synergistic survival benefit in a PBMC-humanized Ramos NOD/SCID mouse model. Conclusions: This study demonstrates that the combination of tafasitamab and rituximab improves efficacy compared to antibody mono treatment in models of aggressive B-cell lymphoma in vitro and in vivo. Translational Relevance: The immunochemotherapy of rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) remains the standard of care for newly diagnosed DLBCL patients. However, 30-40% of patients are refractory or relapse after initial response to the immunochemotherapy, indicating a high-unmet medical need for these patients. Tafasitamab and rituximab target the B-cell surface proteins CD19 and CD20, respectively, and both antibodies feature overlapping modes of action , namely direct cytotoxicity, ADCC and ADCP. In this study, we show that the combination of tafasitamab and rituximab had additive and synergistic efficacy both in vitro and in vivo. Our findings shed new light on the underlying mechanism of the combination of both antibodies and lay the ground to translate the results into improved outcome for patients with aggressive lymphoma in future clinical trials.
Project description:Combination therapy with oncolytic virus and adoptively transferred T cells or mRNA vaccine amplifies antitumor effects [scRNA-Seq]