Tumor-specific donor lymphocyte infusion therapy with allogeneic T cells utilizing novel retrovirus vector silencing endogenous TCR expression

Background Donor Lymphocyte infusion (DLI) is a therapy for the patients with relapsed hematological malignancy after allogeneic hematopoetic stem cell transplantation. However, the development of Graft-Versus-Host Disease (GVHD) is a serious adverse event and the efficacy is limited when one needs to control the GVHD. To inhibit the development of GVHD with increased tumor-specificity of transferred allogeneic lymphocytes, here we demonstrate the development of DLI with lymphocytes engineered to express tumor-specific T cell receptor (TCR) in combination with decreased GVHD-inducing potential utilizing the novel retrovirus vector (siTCR vector) that specifically silences endogenous TCR in gene-engineered T cells.