Anti-CD19 CAR-T Cells(SongGe Biotechnology)

Chimeric antigen receptor T (CAR-T) cells represent a promising approach for cancer immunotherapy, yet their efficacy is hindered by immunosuppressive signals in the tumor microenvironment. Casitas B-cell lymphoma protein b (Cbl-b) is a key negative regulator of T cell function. This study investigated whether inhibiting Cbl-b enhances the antitumor activity of human CAR-T cells. The Cbl-b inhibitor NX-1607 was shown to significantly improve CAR-T cell production and function. When applied during the manufacturing phase, NX-1607 increased the yield of anti-CD19 CAR-T cells. Treatment during the expansion phase enhanced cytokine secretion and cytotoxic activity. Notably, continuous NX-1607 treatment throughout manufacturing and expansion maximized CAR-T cell yield, cytokine production, and cytotoxicity. In vivo, NX-1607-treated CAR-T cells exhibited superior efficacy against hematological malignancies. These findings highlight Cbl-b as a therapeutic target for enhancing CAR-T cell manufacturing efficiency and antitumor efficacy, underscoring its potential for clinical applications.

Dysregulated B-cell activation plays pivotal roles in IgG4-related disease (IgG4-RD), which makes B-cell depletion a potential strategy for IgG4-RD treatment. In this study, we aimed to investigate the feasibility of applying anti-CD19 chimeric antigen receptor T(CAR-T) cell therapy to IgG4-RD treatment in a mouse disease model based on LatY136F knock-in (Lat) mice. We constructed murine anti-CD19 CARs with either CD28 or 4-1BB as the intracellular costimulatory motif and evaluated the therapeutic function of the corresponding CAR-T cells by infusing them into Lat mice. Next, we assessed the safety of CAR-T infusion by evaluating the risk of cytokine release syndrome (CRS) and the antiviral capabilities in a mouse influenza infection model. Finally, we performed human anti-CD19 CAR-T manufacturing from IgG4-RD patients and evaluated its activation level and functional effects in vitro. Compared with 1D3 antibody treatment, the adoptive transfer of anti-CD19 CAR-T cells with CD28 costimulatory motif showed comparable B-cell-depletion effect in Lat mice. Furthermore, the transfer of syngeneic anti-CD19 CAR-T cells also decreased the percentage of plasma cells as well as IL-4 secreting Th cells, therefore attenuating the inflammation and fibrosis condition. CAR-T cells with CD28 costimulatory motif showed better therapeutic efficiency without the incidence of serious CRS events or increasing the risk of infection. In addition, we validated the feasibility of human CAR-T preparation in vitro from IgG4-RD patients. Taken together, these results show that anti-CD19 CAR-T therapy was effective in the treatment of a murine model of IgG4-RD, indicating its potential for clinical use in patients.