Rosmarinic acid interferes with influenza virus A entry and replication by decreasing GSK3ß and phosphorylated AKT expression levels.

BACKGROUND: The purpose of this study was to examine the in vivo activity of rosmarinic acid (RA) - a phytochemical with antioxidant, anti-inflammatory, and antiviral properties - against influenza virus (IAV). An antibody-based kinase array and different in vitro functional assays were also applied to identify the mechanistic underpinnings by which RA may exert its anti-IAV activity. METHODS: We initially examined the potential efficacy of RA using an in vivo mouse model. A time-of-addition assay and an antibody-based kinase array were subsequently applied to investigate mechanism-of-action targets for RA. The hemagglutination inhibition assay, neuraminidase inhibition assay, and cellular entry assay were also performed. RESULTS: RA increased survival and prevented body weight loss in IAV-infected mice. In vitro experiments revealed that RA inhibited different IAV viruses - including oseltamivir-resistant strains. From a mechanistic point of view, RA downregulated the GSK3ß and Akt signaling pathways - which are known to facilitate IAV entry and replication into host cells. CONCLUSIONS: RA has promising preclinical efficacy against IAV, primarily by interfering with the GSK3ß and Akt signaling pathways.

Promoter usage regulating the surface density of CAR molecules may modulate the kinetics of CAR-T cells in vivo.

Although chimeric antigen receptor T (CAR-T) cell therapy achieves high remission rates, challenges (e.g., toxicity management and relapse prevention) remain. The major risks are cytokine release syndrome and related neurological toxicity. The influence of the CAR surface density on the efficacy/safety of CAR-T cell therapy and the factors determining CAR density were not elucidated comprehensively. Here, we discovered that the use of the MND promoter increased the transduction rate and reduced the CAR surface density. Additionally, MND-driven CAR-T cells had prolonged antileukemia activity in a mouse model. In an initial dual-armed anti-CD19 CAR-T cell pilot study (ClinicalTrials.gov: NCT03840317), eight and six subjects were infused with MND and EF1α promoter-driven autologous CAR-T cells (3 × 105 CAR-T cells/kg), respectively. MND subjects developed mild fever and lower interferon gamma (IFN-γ) concentrations than in the EF1A19 group. All but one subject in each cohort reached minimal residual disease (MRD)-negative complete remission after the first month of evaluation. These results represent the first comprehensive study on the promoter-driven modulation of CAR-T cell functionality. These findings encourage further evaluation of the potential of the MND promoter to drive CAR-T cells as a broadly applicable cellular product for anticancer immunotherapy.

Dual specific CD19/CD22-targeted chimeric antigen receptor T-cell therapy for refractory diffuse large B-cell lymphoma: A case report.

Clinical trials of chimeric antigen receptors (CARs) targeting CD19 have produced impressive results in hematological malignancies, including diffuse large B-cell lymphoma (DLBCL). However, a notable number of patients with DLBCL fail to achieve remission after CD19 CAR T-cell therapy and may therefore require a dual targeted CAR T-cell therapy. A 31-year-old man with refractory DLBCL was assessed in the present case report. The patient was treated with sequential infusion of single CD19 CAR T cells followed by dual CD19/CD22-targeted CAR T cells. The outcome was that the patient achieved partial remission after the first single CD19 CAR T-cell infusion and complete remission after the dual CD19/CD22-targeted CAR T-cell infusion. Grade 1 cytokine release syndrome (CRS) was observed after the single CD19 CAR T-cell infusion, while grade 3 CRS and hemophagocytic syndrome were observed after the dual targeted CAR T-cell infusion, but these adverse effects alleviated after the treatments. To the best of our knowledge, the present case report is the first to describe the successful application of dual CD19/CD22-targeted CAR T-cell therapy for the treatment of refractory DLBCL. The report suggests that dual CD19/CD22-targeted CAR T-cell therapy may represent a promising option for the treatment of refractory DLBCL; however, caution should be taken due to potential CRS development.

Evidence of long-lasting anti-CD19 activity of engrafted CD19 chimeric antigen receptor-modified T cells in a phase I study targeting pediatrics with acute lymphoblastic leukemia.

Ninety percent of relapse/refractory B-cell acute lymphatic leukemia (R/R B-ALL) patients can achieve complete remission (CR) after CD19-targeting chimeric antigen receptor T (CAR-T) cell therapy. However, around 50% of them relapse in 1 year. Persistent CAR-T cell engraftment is considered as the key to remain durable remission. Here, we initiated a phase I study to treat 10 pediatric B-ALL patients using a CD19-targeted second generation CAR with a 4-1BB intracellular costimulatory domain. All patients received a standard fludarabine and cyclophosphamide (FC) preconditioning regiment, followed by a CAR-T infusion with a median number of 0.5 (0.3-1.58) × 106 CAR+ T cells/kg. The pretreatment tumor burdens were high with a median bone marrow (BM) blasts percentage of 59.2% (7.31%-86.2%), excluding one patient only with brain infiltration of leukemia cells (0% BM blasts). The initial CR rate was 80% (n = 8/10). Four patients (40%) experienced serious (grade > 2) cytokine release syndrome (CRS) and three patients (30%) with obvious neurotoxicity. Monthly assessments of CD19+ minimal residual disease (MRD) and CAR-T engraftment demonstrated the anti-CD19 activity of long-term engrafted CAR-T cell clones in one patient for more than 2 years.