Engineered Immune Cells and Synthetic Immunotherapy最新文献

{"title":"Abstract A47: Superior expansion of central memory CD8+ T cells using NKG2D-targeted delivery of IL-2: Implications for adoptive T cell immunotherapy","authors":"Kang Li, Lei Shi, Qing Wang, O. Onyema, Yizhan Guo, A. Krupnick","doi":"10.1158/2326-6074.TUMIMM17-A47","DOIUrl":"https://doi.org/10.1158/2326-6074.TUMIMM17-A47","url":null,"abstract":"Infusion of activated autologous lymphocytes or CAR-T cells is a promising clinical treatment for both solid and liquid tumors. Traditional methods for ex vivo T cell expansion have relied on transient stimulation of the T cell receptor in the presence of the common γ-chain cytokines. Although it has been routine for most clinical and experimental laboratories to rely on interleukin-2 (IL2) to support T cell expansion, this cytokine can result in expansion of regulatory T cells (Tregs) and activation induced death of effector cells. Furthermore, prolonged exposure to IL2 may result in differentiation of CD8+ T cells toward an effector phenotype, a terminally differentiated state that provides only short-lived and highly limited protection from malignancy. Alternate gamma chain cytokines, such as IL7 and IL15, do not expand Tregs and may offer an advantage for the expansion of central memory CD8+ T cells, that are superior in mediating tumor regression. Nevertheless, optimal protocols for T cell expansion have yet to be defined. We have recently demonstrated that IL2 targeted to NKG2D-expressing cells using the viral decoy ligand known as orthopox major histocompatibility complex class I-like protein (or OMCP for short), offers a superior method for NK cell expansion and NK mediated immunotherapy (Nat Commun 2016 Sep 21;7. doi: 10.1038/ncomms12878). The possibility of using this redirected cytokine (called OMCP-IL2 for short) for ex vivo CD8+ T cell expansion has not been explored. To directly compare several common gamma cytokines bulk T cells from C57BL/6 mice were cultured with transient CD3/CD28 stimulation in the presence of wild-type IL2, OMCP-IL2 or combination IL15/IL7 at 100IU/ml. While both IL2 and IL15/IL7 resulted in substantial T cell expansion by day 12 of culture (5.8±0.7 and 3.4±0.16-fold expansion respectively) OMCP-IL2 treated cultures resulted in 10±0.8 fold expansion by the same time point. Furthermore, IL2 and IL15/IL7-treated cultures did not expand further after two weeks of cytokine treatment while OMCP-IL2 treated cultures expanded for 40 days (reaching a 27±0.7-fold expansion). Flow cytometric analysis revealed that the higher CD8+ T cell numbers in OMCP-IL2 treated cultures were due to both increased proliferation (%KI67 positivity in 49±9%, 70±2% and 86±3% of CD8+ T cells for IL2, IL15/IL7 and OMCP-IL2 treated cultures respectively) and improved viability (27±2%, 20±2% and 79±1.8% viable cells for IL2, IL15/IL7 and OMCP-IL2-treated cultures respectively). While wild-type IL2 expanded both CD8+ and CD4+ T cells OMCP-IL2 preferentially expanded CD8+ T cells. Phenotypic analysis revealed that the majority of CD8+ T cells expanded in OMCP-IL2 were CD44hiCD62Lhi central memory T cells while those expanded in IL2 were primarily CD44hiCD62Llow effector cells. Consistent with this a starting population of 1 million T cells resulted in 60,756±21,813; 368,756±30,217; and 7,605,870±872,870 CD8+ central memory T cells after three w","PeriodicalId":323684,"journal":{"name":"Engineered Immune Cells and Synthetic Immunotherapy","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132310789","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Abstract A59: Expression of membrane-bound IL-15/IL-15Rα complex in chimeric antigen receptor-engineered natural killer cells for enhanced efficacy against solid tumors","authors":"Elizabeth L. Siegler, Pin Wang","doi":"10.1158/2326-6074.TUMIMM17-A59","DOIUrl":"https://doi.org/10.1158/2326-6074.TUMIMM17-A59","url":null,"abstract":"The natural killer cell line NK92 has shown exciting potential as an anticancer immunotherapeutic tool in both preclinical models and in clinical trials. Preclinical studies have demonstrated improved antitumor responses after modifying NK92 cells with chimeric antigen receptors (CARs), which redirect immune cell activity to target cancer cells. CARs typically contain an antibody-derived extracellular domain, which binds to the desired tumor-associated antigen (TAA) and triggers an intracellular signaling cascade to activate the immune cell against the target cell. While CAR-based therapies have had remarkable success in treating hematological cancers, treatment of solid tumors has encountered many obstacles, including a lack of persistence and immunosuppression within the tumor microenvironment. Researchers have tried to circumvent these issues through the systemic delivery of cytokines such as IL-2 and IL-15. However, the delivery of supraphysiological cytokine concentrations is inefficient and has led to toxicities and unwanted side effects in the clinic. More recently, immune cells have been modified to ectopically express cytokines such as IL-15 to provide autocrine stimulation. IL-15 has been shown to activate and promote the proliferation of immune cells such as T and NK cells upon binding to its receptor, IL-15Rα. Recombinant IL-15 bound to IL-15Rα has been tested in clinical trials to boost antitumor immunity, as it imitates the physiological transpresentation of endogenous IL-15. We have transduced NK92 cells with either a CAR targeted against the human TAA mesothelin (αmeso.NK) or a bicistronic vector containing the αmeso CAR and a membrane-bound human IL-15/IL-15Rα complex (αmeso.mbIL15.NK). Both retroviral vectors demonstrated efficient transduction of NK92 cells, with 55% and 40% transduction efficiency, respectively. CAR+ populations were further selected via fluorescence activated cell sorting. The inclusion of the mbIL15 complex allowed the αmeso.mbIL15.NK cells to continue to proliferate in vitro in the absence of exogenous IL-2 and further enriched CAR expression when tested in an unsorted population. In contrast, αmeso.NK cells without the mbIL15 complex were unable to proliferate without exposure to IL-2 in culture, resulting in cell death and loss of CAR expression within five days. We will compare αmeso.NK and αmeso.mbIL15.NK cells to determine if the mbIL15 complex enhances cytokine secretion and cytotoxicity in the presence of mesothelin-expressing cancer cells in vitro. We further hypothesize that αmeso.mbIL15.NK cells will demonstrate superior proliferation and persistence in a mouse model without additional cytokine supplementation when compared to αmeso.NK cells. NK92 cells represent a viable allogenic, off-the-shelf anticancer immunotherapy, and CAR-engineered NK92 cells have shown promise in preclinical solid tumor models. The addition of membrane-bound IL-15/IL-15Rα complex may further enhance cytotoxic effects as ","PeriodicalId":323684,"journal":{"name":"Engineered Immune Cells and Synthetic Immunotherapy","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130845810","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}