Chimeric antigen receptor (CAR)-modified T cell therapy has achieved remarkable efficacy in treating hematological malignancies, but it confronts many challenges in treating solid tumors, such as the immunosuppressive microenvironment of the solid tumors. These factors reduce the antitumor activity of CAR-T cells in clinical trials. Therefore, we used the immunocytokine interleukin-12(IL-12) to enhance the efficacy of CAR-T cell therapy. In this study, we engineered CAR-IL12R54 T cells that targeted mesothelin (MSLN) and secreted a single-chain IL-12 fused to a scFv fragment R54 that recognized a different epitope on mesothelin. The evaluation of the anti-tumor activity of the CAR-IL12R54 T cells alone or in combination with anti-PD-1 antibody in vitro and in vivo was followed by the exploration of the functional mechanism by which the immunocytokine IL-12 enhanced the antitumor activity. CAR-IL12R54 T cells had potency to lyse mesothelin positive tumor cells in vitro. In vivo studies demonstrated that CAR-IL12R54 T cells were effective in controlling the growth of established tumors in a xenograft mouse model with fewer side effects than CAR-T cells that secreted naked IL-12. Furthermore, combination of PD-1 blockade antibody with CAR-IL12R54 T cells elicited durable anti-tumor responses. Mechanistic studies showed that IL12R54 enhanced Interferon-γ (IFN-γ) production and dampened the activity of regulatory T cells (Tregs). IL12R54 also upregulated CXCR6 expression in the T cells through the NF-κB pathway, which facilitated T cell infiltration and persistence in the tumor tissues. In summary, the studies provide a good therapeutic option for the clinical treatment of solid tumors.

Introduction: B7-H6, a tumor-specific immune checkpoint molecule within the B7 family, represents a promising therapeutic target due to its selective overexpression in malignancies and negligible expression in normal tissues.Method: Here, we developed bispecific antibodies (BsAbs) targeting B7-H6 to redirect T and NK cells against solid tumors. Through phage display, 15 high-affinity B7-H6 monoclonal antibodies were generated.Results: Two optimized BsAbs, B7-H6M4-OKT3 (T cell-engaging) and B7-H6M4-LC21 (NK cell-engaging), were constructed in and scFv-hFc-scFv format. Both demonstrated nanomolar affinity (EC50: 0.04–1.22 nM) and selective cytotoxicity against B7-H6+ cells (H446, Huh-7, HepG2), while showing minimal cytotoxicity against B7-H6-negative cells (A431). B7-H6M4LC21 exhibited enhanced tumor-killing efficacy (IC50: 5 ng/mL) compared to B7H6M4-OKT3(IC50: 1 ng/mL) when combined with an IL-15/IL-15Ra sushi fusion protein, which augmented NK cell proliferation and cytotoxicity. In H446 xenograft models, both BsAbs suppressed tumor growth in a dose-dependent manner (0.1–20 mg/kg) without significant toxicity. Combination therapy with B7-H6M4-LC21 (10 mg/kg) and B7-H6M18/IL-15/IL-15Ra sushi (0.03 mg/kg) achieved synergistic tumor inhibition (p<0.05), surpassing the efficacy of T cell-based combinations.Discussion: These findings establish B7-H6-targeted BsAbs combined with cytokine engineering as a viable strategy for treating refractory solid tumors.

Canine distemper virus (CDV) remains a highly contagious and lethal pathogen, posing a severe global threat to domestic dogs and wild carnivores. To address the urgent need for effective interventions, we utilized a proprietary Vero-SLAM cell platform to isolate a wild-type CDV strain and generate neutralizing polyclonal antibodies. Subsequently, phage display technology was employed to screen for single-chain variable fragments (scFvs) targeting the CDV hemagglutinin protein (CDV-H). This approach led to the identification of a specific scFv with virus-binding affinity comparable to commercial antibodies, which effectively blocks CDV infection in Vero-SLAM cells. Molecular docking and molecular dynamics simulations were conducted to elucidate the interaction mechanism, suggesting that this scFv binds to a novel and unique epitope on the CDV-H. These findings not only expand our understanding of the antigenic properties of the CDV H protein but also provide a theoretical foundation and a promising candidate molecule for the development of future CDV diagnostics and antiviral strategies.

Metabolic dysregulation has been reported involving in the clinical outcomes of multiple cancers. However, systematical identification of the impact of metabolic pathways on cancer prognosis is still lacking. Here, we performed a pan-cancer analysis of popular metabolic checkpoint genes and pathways with cancer prognosis by integrating information of clinical survival with gene expression and pathway activity in multiple cancer patients. By discarding the effects of age and sex, we revealed extensive and significant associations between the survival of cancer patients and the expression of metabolic checkpoint genes, as well as the activities of three primary metabolic pathways: amino acid metabolism, carbohydrate metabolism, lipid metabolism, and eight nonprimary metabolic pathways. Among multiple cancers, we found the survival of kidney renal clear cell carcinoma and low-grade glioma exhibit high metabolic dependence. Our work systematically assesses the impact of metabolic checkpoint genes and pathways on cancer prognosis, providing clues for further study of cancer diagnosis and therapy.