B7-H3 chimeric antigen receptor-modified T cell shows potential for targeted treatment of acute myeloid leukaemia.

BACKGROUND AND AIMS: Chimeric antigen receptor (CAR)-T cell therapy is a novel type of immunotherapy. However, the use of CAR-T cells to treat acute myeloid leukaemia (AML) has limitations. B7-H3 is expressed in several malignancies, including some types of AML cells. However, its expression in normal tissues is low. Therefore, B7-H3 is ideal for targeted AML therapy. MATERIALS AND METHODS: First, we constructed B7-H3 CAR that can target B7-H3, and then constructed B7-H3-CAR-T cells in vitro, which were co-incubated with six AML cell lines expressing different levels of B7-H3, respectively. The toxicity and cytokines were detected by flow cytometry. In vivo, AML model was established in B-NSG mice to study the toxicity of B7-H3-CAR T on AML cells. RESULTS: In vitro functional tests showed that B7-H3-CAR-T cells were cytotoxic to B7-H3-positive AML tumor cells and had good scavenging effect on B7-H3-expressing AML cell lines, and the cytokine results were consistent. In vivo, B7-H3-CAR-T cells significantly inhibited tumor cell growth in a mouse model of AML, prolonging mouse survival compared with controls. CONCLUSION: B7-H3-CAR-T cells may serve as a novel therapeutic method for the targeted treatment of AML.

Pharmacological Effect of Panax notoginseng Saponins on Cerebral Ischemia in Animal Models.

Panax notoginseng saponins (PNS), bioactive compounds, are commonly used to treat ischemic heart and cerebral diseases in China and other Asian countries. Most previous studies of PNS have focused on the mechanisms underlying their treatment of ischemic cardiovascular diseases but not cerebral ischemic diseases. This study sought to explore the pharmacological mechanisms underlying the effectiveness of PNS in treating cerebral ischemic diseases. Different experimental cerebral ischemia models (including middle cerebral artery occlusion (MCAO) and the blockade of four arteries in rats, collagen-adrenaline-induced systemic intravascular thrombosis in mice, thrombosis of carotid artery-jugular vein blood flow in the bypass of rats, and hypoxia tolerance in mice) were used to investigate the mechanisms underlying the actions of PNS on cerebral ischemia. The results indicated that (1) PNS improved neurological function and reduced the cerebral ischemia infraction area in MCAO rats; (2) PNS improved motor coordination function in rats with complete cerebral ischemia (blockade of four arteries), decreased Ca2+ levels, and ameliorated energy metabolism in the brains of ischemia rats; (3) PNS reduced thrombosis in common carotid artery-jugular vein blood flow in the bypass of rats; (4) PNS provided significant promise in antistroke hemiplegia and hypoxia tolerance in mice. In conclusion, PNS showed antagonistic effects on ischemic stroke, and pharmacological mechanisms are likely to be associated with the reduction of cerebral pathological damage, thrombolysis, antihypoxia, and improvement in the intracellular Ca2+ overload and cerebral energy metabolism.

MUC1-Tn-targeting chimeric antigen receptor-modified Vγ9Vδ2 T cells with enhanced antigen-specific anti-tumor activity.

Chimeric antigen receptor (CAR) αß T cell adoptive immunotherapy has shown great promise for improving cancer treatment. However, there are several hurdles to overcome for the wide clinical application of CAR-αß T cells therapy, including side effects and a limited T cells source from cancer patients. Therefore, we sought to identify an alternative T cell subset that could avoid these limitations and improve the effectiveness of CAR-T immunotherapy. γδ T cells are a minor subset of T cells, which share the characteristic of innate immune cells and adaptive immune cells. Vγ9Vδ2 T cells are a predominant γδ T subset in the circulating peripheral blood. In this study, we investigated the antigen-specific antitumor activity of CAR-Vγ9Vδ2 T cells targeting MUC1-Tn antigen. Vγ9Vδ2 T cells were expanded from peripheral blood mononuclear cells of healthy volunteers with zoledronic acid and interleukin-2. CAR-Vγ9Vδ2 T cells were generated by transfection of lentivirus encoding MUC1-Tn CAR. Cytotoxicity assays with various cancer cell lines revealed that CAR-Vγ9Vδ2 T cells could effectively lyse tumor cells in an antigen-specific manner, with similar or stronger effects than CAR-αß T cells. However, CAR-Vγ9Vδ2 T cells had shorter persistence, which could be improved with the addition of IL-2 to maintain the function of CAR-Vγ9Vδ2 T cells with consecutive stimulation of tumor cells. Using a xenograft mouse model, we further showed that CAR-Vγ9Vδ2 T cells more effectively suppressed tumor growth in vivo than Vγ9Vδ2 T cells. Therefore, MUC1-Tn CAR-modified Vγ9Vδ2 T cells may represent a novel, promising ready-to-use product for cancer allogeneic immunotherapy.

Research progression on the first-line biological target therapy of advanced / 中国肿瘤生物治疗杂志

@#[Abstract] Objective: To develop a new type of CD7 chimeric antigen receptor modified T cell (CD7-CAR-T) for the treatment of CD7 positive acute myeloid leukemia (AML), and to observe its killing effect on CD7 positive AML cells. Methods: The CD7-CAR lentiviral vector was constructed based on the CD7 Nanobody sequence and costimulatory domain sequence of CD28 and 4-1BB. The lentiviral particles were packaged and used to co-transfect human T cells with protein expression blocker (PEBL), so as to prepare CD7- CAR-T cells. Real time cellular analysis (RTCA) was used to monitor the cytotoxicity of CD7-CAR-T cells on CD7 overexpressed 293T cells. Flow cytometry assay was used to detect the effect of CD7-CAR-T cells on proliferation and cytokine secretion of AML cells with high, medium and low CD7 expressions (KG-1, HEL and Kasumi-1 cells, respectively). Results: CD7-CAR-T cell was successfully constructed and its surface expression of CD7 was successfully blocked. Compared with T cells, CD7-CAR-T cells could significantly inhibit the proliferation of CD7-293T cells and promote the release of TNF, Granzyme B and INF-γ; in addition, CD7-CAR-T cells also significantly promoted the apoptosis (t=147.1, P<0.01; t=23.57, P<0.01) and cytokine release (P<0.05 or P<0.01) in CD7 positive KG-1 and HEL cells, but had little effect on Kasumi-1 cells that only expressed minimal CD7 antigen (t=0.7058, P>0.05). Conclusion: CD7-CAR-T cells can specifically kill CD7-positive AML cells in vitro.

Phase 1 clinical trial demonstrated that MUC1 positive metastatic seminal vesicle cancer can be effectively eradicated by modified Anti-MUC1 chimeric antigen receptor transduced T cells.

Recent progress in chimeric antigen receptor-modified T-cell (CAR-T cell) technology in cancer therapy is extremely promising, especially in the treatment of patients with B-cell acute lymphoblastic leukemia. In contrast, due to the hostile immunosuppressive microenvironment of a solid tumor, CAR T-cell accessibility and survival continue to pose a considerable challenge, which leads to their limited therapeutic efficacy. In this study, we constructed two anti-MUC1 CAR-T cell lines. One set of CAR-T cells contained SM3 single chain variable fragment (scFv) sequence specifically targeting the MUC1 antigen and co-expressing interleukin (IL) 12 (named SM3-CAR). The other CAR-T cell line carried the SM3 scFv sequence modified to improve its binding to MUC1 antigen (named pSM3-CAR) but did not co-express IL-12. When those two types of CAR-T cells were injected intratumorally into two independent metastatic lesions of the same MUC1(+) seminal vesicle cancer patient as part of an interventional treatment strategy, the initial results indicated no side-effects of the MUC1 targeting CAR-T cell approach, and patient serum cytokines responses were positive. Further evaluation showed that pSM3-CAR effectively caused tumor necrosis, providing new options for improved CAR-T therapy in solid tumors.