A CTLA-4 blocking strategy based on Nanobody in dendritic cell-stimulated cytokine-induced killer cells enhances their anti-tumor effects

Abstract

Background Cytokine-induced killer cells induced with tumor antigen-pulsed dendritic cells (DC-CIK) immunotherapy is a promising strategy for the treatment of malignant tumors. However, itsefficacy isrestricted by the immunosuppression, which is mediated by the cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) pathway. In order to overcome the negative co-stimulation from these T cells,we screened a nanobody targeted for CTLA-4 (Nb36) and blocked the CTLA-4 signaling with Nb36. Methods Peripheral blood mononuclear cells (PBMCs) were collected from healthy donors to beused to induce CIK cells in vitro, after which they were co-cultured with DC cells that had received tumor antigens. In addition, wetested whether blocking CTLA-4 signaling with Nb36 could promote in vitro DC-CIK cells proliferation, pro-inflammatory cytokine production and cytotoxicity,or not. For the in vivo experiments, we constructed a subcutaneously transplanted tumor model and placed it in NOD/SCID mice to verify the anti-tumor effect of this therapy. Results After stimulation with Nb36, the DC-CIK cells presented enhanced proliferation and production of IFN-γ in vitro, which strengthened the killing effect on the tumor cells. For the in vivo experiments, it was found that Nb36-treated DC-CIK cells significantly inhibited the growth of subcutaneously transplanted livercancer tumors, as well as reduced the tumor weight and prolonged the survival of tumor-bearing NOD/SCID mice. Conclusions Ourfindings demonstrated that in response to CTLA-4 specific nanobody stimulation, DC-CIK cells exhibited a better anti-tumor effect. In fact, this Nb-based CTLA-4 blocking strategy achieved an anti-tumor efficacy close to that of monoclonal antibodies. Our findings suggest that DC-CIK cells + Nb36 have the potential totreatmalignant tumors through in vivo adoptive therapy.

The safety and anti-tumor effect of multiple peptides-pulsed dendritic cells combined with induced specific cytotoxic T lymphocytes for patients with solid tumors

“…CTLs can directly kill tumor cells quickly, efficiently and specifically through the cytokine secretion ( 33 , 34 ). As reported, the secretion of IFN-γ was associated with the response of tumor-specific T cells, and exerts anti-tumor effects by inhibiting tumor-cell proliferation and promoting tumor cell apoptosis ( 35 – 38 ). As a consequence, the production of IFN-γ exhibits an intensely synergistic boost to antigen-specific immune responses during immunotherapy ( 39 ).…”

Single-cell transcriptome analysis profiles the expression features of TMEM173 in BM cells of high-risk B-cell acute lymphoblastic leukemia

“…As an important member of immune regulation, DC is essential for the anti-tumor immune response [ 47 ]. DCs were then isolated from BM cells and subjected to feature analysis.…”

Visual analysis of global research on immunotherapy for gastric cancer: A literature mining from 2012 to 2022

“…The early period focused on “#3 cytokine-induced killer” and “#8 myeloid-derived suppressor cells.” Current study suggested that compared to other immune cells, CIKs have stronger antitumor activity, broader antitumor spectrum and higher proliferation rate. 50 The latest meta-analysis suggested that CIKs or combined dendritic cell (DC)-CIKs has advantages in enhancing immune function, alleviating adverse events and prolonging the survival in GC patients. 51 The early period also focused on myeloid-derived suppressor cells (MDSCs).…”