Chimeric antigen receptor (CAR)-expressing macrophages (CAR-M) have a great potential to improve cancer therapy, as shown from several recent preclinical studies. However, unlike CAR-T cell therapy, which has been widely studied, the efficacy and limitations of CAR-M cells remain to be established. To address this issue, in the present study, we compared three intracellular signaling domains (derived from common γ subunit of Fc receptors (FcRγ), multiple EGF-like-domains protein 10 (Megf10), and the CD19 cytoplasmic domain that recruits the p85 subunit of phosphoinositide-3 kinase (PI3K), respectively) for their ability to promote primary CAR-M functions, and investigated the potential synergistic effect between CAR-M and CAR-T cells in their ability to kill tumor cells. We found that CAR-MFcRγ exerted more potent phagocytic and tumor-killing capacity than CAR-MMegf10 and CAR-MPI3K. CAR-M and CAR-T demonstrated synergistic cytotoxicity against tumor cells in vitro. Mechanistically, the inflammatory factors secreted by CAR-T increased the expression of costimulatory ligands (CD86 and CD80) on CAR-M and augmented the cytotoxicity of CAR-M by inducing macrophage M1 polarization. The upregulated costimulatory ligands may promote the fitness and activation of CAR-T cells in turn, achieving significantly enhanced cytotoxicity. Taken together, our study demonstrated for the first time that CAR-M could synergize with CAR-T cells to kill tumor cells, which provides proof-of-concept for a novel combinational immunotherapy.

Remarkable improvement relative to traditional approaches in the treatment of hematological malignancies by chimeric antigen receptor (CAR) T-cell therapy has promoted sequential approvals of eight commercial CAR T products within last 5 years. Although CAR T cells’ productization is now rapidly boosting their extensive clinical application in real-world patients, the limitation of their clinical efficacy and related toxicities inspire further optimization of CAR structure and substantial development of innovative trials in various scenarios. Herein, we first summarized the current status and major progress in CAR T therapy for hematological malignancies, then described crucial factors which possibly compromise the clinical efficacies of CAR T cells, such as CAR T cell exhaustion and loss of antigen, and finally, we discussed the potential optimization strategies to tackle the challenges in the field of CAR T therapy.

Aim: To investigate the influence of DDX11-AS1 on paclitaxel (PTX) resistance in lung adenocarcinoma (LUAD). Methods: LncRNA expression and functional enrichment analyses were processed via bioinformatics methods. DDX11-AS1 expression was detected via quantitative real-time PCR. Cell counting kit-8, colony formation, flow cytometry and comet assays were manipulated to measure cell proliferation, apoptosis, cell cycle and DNA damage repair, respectively. Western blot was used to assess DNA damage-related protein expression. Results: DDX11-AS1 was in a high expression status in LUAD, and could promote LUAD cell proliferation and PTX resistance, while suppressing cell apoptosis. DNA damage repairing ability was also modulated by the change of DDX11-AS1 expression. Conclusion: LncRNA DDX11-AS1 promotes DNA damage repair to enhance PTX resistance in LUAD.