Junjun Lu

Immune checkpoint therapy has resulted in remarkable improvements in the outcome for certain cancers. To broaden the clinical impact of checkpoint targeting, we devised a strategy that couples targeting of the cytokine-inducible Src homology 2-containing (CIS) protein, a key negative regulator of interleukin 15 (IL-15) signaling, with fourth-generation "armored" chimeric antigen receptor (CAR) engineering of cord blood-derived natural killer (NK) cells. This combined strategy boosted NK cell effector function through enhancing the Akt/mTORC1 axis and c-MYC signaling, resulting in increased aerobic glycolysis. When tested in a lymphoma mouse model, this combined approach improved NK cell antitumor activity more than either alteration alone, eradicating lymphoma xenografts without signs of any measurable toxicity. We conclude that targeting a cytokine checkpoint further enhances the antitumor activity of IL-15-secreting armored CAR-NK cells by promoting their metabolic fitness and antitumor activity. This combined approach represents a promising milestone in the development of the next generation of NK cells for cancer immunotherapy.

Abstract Virus-specific T cells have proven highly effective for the treatment of severe and drug-refractory infections after hematopoietic stem cell transplant (HSCT). However, the efficacy of these cells is hindered by the use of glucocorticoids, often given to patients for the management of complications such as graft-versus-host disease. To address this limitation, we have developed a novel strategy for the rapid generation of good manufacturing practice (GMP)–grade glucocorticoid-resistant multivirus-specific T cells (VSTs) using clustered regularly interspaced short palindromic repeats (CRISPR)–CRISPR-associated protein 9 (Cas9) gene-editing technology. We have shown that deleting the nuclear receptor subfamily 3 group C member 1 (NR3C1; the gene encoding for the glucocorticoid receptor) renders VSTs resistant to the lymphocytotoxic effect of glucocorticoids. NR3C1-knockout (KO) VSTs kill their targets and proliferate successfully in the presence of high doses of dexamethasone both in vitro and in vivo. Moreover, we developed a protocol for the rapid generation of GMP-grade NR3C1 KO VSTs with high on-target activity and minimal off-target editing. These genetically engineered VSTs promise to be a novel approach for the treatment of patients with life-threatening viral infections post-HSCT on glucocorticoid therapy.

BACKGROUND: B cells play a pivotal role in regulating the immune response. The induction of B cell-mediated immunosuppressive function requires B cell activating signals. However, the mechanisms by which activated B cells mediate T-cell suppression are not fully understood. METHODS: We investigated the potential contribution of metabolic activity of activated B cells to T-cell suppression by performing in vitro experiments and by analyzing clinical samples using mass cytometry and single-cell RNA sequencing. RESULTS: Here we show that following activation, B cells acquire an immunoregulatory phenotype and promote T-cell suppression by metabolic competition. Activated B cells induced hypoxia in T cells in a cell-cell contact dependent manner by consuming more oxygen via an increase in their oxidative phosphorylation (OXPHOS). Moreover, activated B cells deprived T cells of glucose and produced lactic acid through their high glycolytic activity. Activated B cells thus inhibited the mammalian target of rapamycin pathway in T cells, resulting in suppression of T-cell cytokine production and proliferation. Finally, we confirmed the presence of tumor-associated B cells with high glycolytic and OXPHOS activities in patients with melanoma, associated with poor response to immune checkpoint blockade therapy. CONCLUSIONS: We have revealed for the first time the immunomodulatory effects of the metabolic activity of activated B cells and their possible role in suppressing antitumor T-cell responses. These findings add novel insights into immunometabolism and have important implications for cancer immunotherapy.

To investigate the effects of different anesthetic methods on postoperative immune function in patients undergoing gastrointestinal tumor resection. Ninety patients undergoing laparoscopic gastrointestinal tumor resection were divided into 3 groups. Patients in the GA group were anesthetized by total intravenous anesthesia. The GE group was anesthetized by general anesthesia combined with epidural anesthesia. The GN group was anesthetized by general anesthesia combined with bilateral Transversus Abdominis Plane block (TAP) and rectus sheath nerve blocks. General anesthesia is total intravenous anesthesia in all three groups. Blood samples were taken to test the changes of peripheral lymphocyte subtype analysis, and levels of plasma cortisol, epinephrine, norepinephrine. Also, the dosage of anesthetic drugs, recovery time, and visual analog scale (VAS) scores were recorded. Postoperative immune indexes, including CD4 count, CD8 count, B, and NK cells, in the GE group were significantly higher than those in NA and GA groups (P < 0.01). Perioperative stress indices, including epinephrine levels, norepinephrine level and aldosterone level, in the GE group were significantly lower than in the GA group and GN group (P < 0.01). The intraoperative/total sufentanil dosage and remifentanil dosage in the GE group were significantly lower than those in the GA and GN groups (P < 0.01). The VAS scores in the GE group were significantly better than those in GA and GN groups (P < 0.01). General anesthesia combined with epidural anesthesia attenuates the increase in inflammatory mediators. Its possible mechanisms include reducing perioperative stress response and reducing perioperative opioid use.