Zeb2 regulates differentiation of long-lived effector of invariant natural killer T cells.

After activation, some invariant natural killer T (iNKT) cells are differentiated into Klrg1+ long-lived effector NKT1 cells. However, the regulation from the effector phase to the memory phase has not been elucidated. Zeb2 is a zinc finger E homeobox-binding transcription factor and is expressed in a variety of immune cells, but its function in iNKT cell differentiation remains also unknown. Here, we show that Zeb2 is dispensable for development of iNKT cells in the thymus and their maintenance in steady state peripheral tissues. After ligand stimulation, Zeb2 plays essential roles in the differentiation to and maintenance of Klrg1+ Cx3cr1+GzmA+ iNKT cell population derived from the NKT1 subset. Our results including single-cell-RNA-seq analysis indicate that Zeb2 regulates Klrg1+ long-lived iNKT cell differentiation by preventing apoptosis. Collectively, this study reveals the crucial transcriptional regulation by Zeb2 in establishment of the memory iNKT phase through driving differentiation of Klrg1+ Cx3cr1+GzmA+ iNKT population.

Combination of cancer vaccine with CD122-biased IL-2/anti-IL-2 Ab complex shapes the stem-like effector NK and CD8+ T cells against tumor.

BACKGROUND: A key to success of cancer immunotherapy is the amplification and sustenance of various effector cells. The hallmark of prominent antitumor T cells is their long-term effector function. Although interleukin (IL)-2 is an attractive cytokine, several attempts have been made towards developing IL-2 modalities with improved effectiveness and safety that enhance natural killer (NK) cells or T cells in cancer models. However, whether such IL-2 modalities can simultaneously support long-term innate and adaptive immunity, particularly stem-like memory, has not been shown. To resolve this issue, we compared the antitumor cellular mechanism with two IL-2/anti-IL-2 complexes (IL-2Cxs) administered in combination with a therapeutic cancer vaccine, which we had previously established as an in vivo dendritic cell-targeting therapy. METHODS: Two types of IL-2Cxs, CD25-biased IL-2Cx and CD122-biased IL-2Cx, together with a Wilms' tumor 1-expressing vaccine, were evaluated in a leukemic model. The immunological response and synergistic antitumor efficacy of these IL-2Cxs were then evaluated. RESULTS: When CD25-biased or CD122-biased IL-2Cxs in combination with the vaccine were assessed in an advanced-leukemia model, the CD122-biased IL-2Cx combination showed 100% survival, but the CD25-biased IL-2Cx did not. We first showed that invariant natural killer T (NKT) 1 cells are predominantly activated by CD122-biased IL-2Cx. In addition, in-depth analysis of immune responses by CD122-biased IL-2Cx in lymphoid tissues and the tumor microenvironment revealed a dramatic increase in the distinct subsets of NK and CD8+ T cells with stem-like phenotype (CD27+Sca-1hi, CXCR3hi, CD127+TCF-1+T-bet+ Eomes+). Moreover, CD122-biased IL-2Cx combination therapy maintained long-term memory CD8+ T cells capable of potent antitumor protection. After the high dimensional profiling analysis of NK and CD8+T cells, principal component analysis revealed that the stem-like-NK cell and stem-like-CD8+T cell state in the combination were integrated in the same group. CONCLUSIONS: CD122-biased IL-2Cx combined with the vaccine can induce a series of reactions in the immune cascade, including activation of not only NKT1 cells, but also NK and CD8+ T cells with a stem-like memory phenotype. Since it can also lead to a long-term, strong antitumor response, the combination of CD122-biased IL-2Cx with a vaccine may serve as a potential and competent strategy for patients with advanced cancer.

A single immunization with cellular vaccine confers dual protection against SARS-CoV-2 and cancer.

The efficacy of current coronavirus disease 2019 (COVID-19) vaccines has been demonstrated; however, emerging evidence suggests insufficient protection in certain immunocompromised cancer patients. We previously developed a cell-based anti-cancer vaccine platform involving artificial adjuvant vector cells (aAVCs) capable of inducing a strong adaptive response by enhancing the innate immunity. aAVCs are target antigen-transfected allogenic cells that simultaneously express the natural killer T-cell ligand-CD1d complex on their surface. In the present study, we applied this system for targeting the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein (CoV-2-S) using CoV-2-S-expressing aAVCs (aAVC-CoV-2) and evaluated the immune response in a murine model. A single dose of aAVC-CoV-2 induced a large amount of CoV-2-S-specific, multifunctional CTLs in addition to CD4+ T-cell-dependent anti-CoV-2-S-specific Abs. CoV-2-S-specific CTLs infiltrated the lung parenchyma and persisted as long-term memory T cells. Furthermore, we immunized mice with CoV-2-S- and tumor-associated antigen (TAA)-co-expressing aAVCs (aAVC-TAA/CoV-2) and evaluated whether the anti-SARS-CoV-2 and antitumor CTLs were elicited. We found that the aAVC-TAA/CoV-2-S therapy exerted apparent antitumor effects and induced CoV-2-S-specific CTLs. These findings suggest aAVC-TAA/CoV-2-S therapy as a promising vaccine candidate for preventing COVID-19, as well as enhancing the effectiveness of cancer therapies.

Effects of structural and electronic characteristics of chalcones on the activation of peroxisome proliferator-activated receptor gamma.

Chalcones share some structural similarities with GW-1929, a highly-selective and potent agonist for peroxisome proliferator-activated receptor-gamma (PPARγ). In this study, we tested 53 structurally diverse chalcones to identify characteristics essential for PPARγ activation in a GAL4-based transactivation assay. This screen identified several novel chalcone agonists of PPARγ. Our results indicate that chalcones with an electron rich group or sterically large groups such as naphthyl on the carbonyl side tend to activate PPARγ. The absence of any strict structural or electronic requirements suggests that the flexibility of the PPARγ ligand binding pocket may allow binding of diverse chalcones with some preference for a slightly larger electron-rich group on the carbonyl side. We predict that further structure-activity relationship studies on chalcones with naphthalene or electron-rich groups near the carbonyl moiety will lead to the development of more potent PPARγ agonists.