IL-2 and IL-15 play an important roles in regulating the lymphocyte function and homeostasis. Advances in understanding of the cellular and molecular biology of IL-2 and IL-15 and their receptor complex have provided rationale to better utilize them to expand and activate immune effectors in patients with cancer. These two cytokines stimulate similar responses from lymphocytes in vitro, but play markedly distinct roles in lymphoid biology in vivo. Their distinct physiological functions can be ascribed to distinct signaling pathways initiated by distinct cytokine receptor subunits, differential expression patterns of their receptors. Recently, the discovery of a novel mechanism of IL-15 cytokine signaling, trans-presentation, has provided insights into the divergent ways of these cytokine function. Although their heterotrimeric receptors have two receptor subunits in common, these two cytokines have contrasting roles in adaptive immune responses. The unique role of interleukin 2 is in the elimination of self-reactive T cells to prevent autoimmunity. By contrast, interleukin 15 is dedicated to the prolonged maintenance of memory T-cell responses to pathogens. As discussed in this article, the biology of IL-2 and IL-15 two cytokines will affect the development of novel treatment for malignancies and autoimmune diseases.
Humans ; Immunotherapy ; Interleukin-15 ; immunology ; metabolism ; Interleukin-2 ; immunology ; metabolism

The study aims to explore the active molecules of traditional Chinese medicine that specifically bind to interleukin-15 receptor α (IL-15Rα) using molecular docking and surface plasmon resonance (SPR) technology. AutoDock molecular docking software was used to perform simulated docking of more than 3 000 compounds from 48 traditional Chinese medicines at IL-15Rα and screen the specific binding compounds. Then Biocore T200 biomolecular interaction analysis system of SPR was used to confirm the binding specificity of the selected target compounds. Finally, the biological effects of the target compounds on IL-15Rα were verified by cell biological experiments. The results showed that neoprzewaquinone A (Neo) possessed the highest specific binding affinity among the active molecules from traditional Chinese medicine, and the dissociation constant (K_D) value was (0.62 ± 0.20) µmol/L. The results of cell experiment showed that Neo significantly inhibited the proliferation of Mo7e cells induced by IL-15, and the IC₅₀ was 1.075 µmol/L, approximately 1/120 of the IC₅₀ of Cefazolin (IL-15 specific antagonist). These results suggest that Neo is a specific inhibitor of IL-15Rα and may be a potential active drug for the treatment of diseases related to the dysfunction of the IL-15Rα signaling.
Molecular Docking Simulation ; Interleukin-15/pharmacology* ; Surface Plasmon Resonance ; Interleukin-15 Receptor alpha Subunit/metabolism* ; Protein Binding

This review attempts to define the relationship between IL-15 and autoimmune disease (AID) from IL-15's tissue distribution, expression regulation and biologic function. Meanwhile, five IL-15 dysregulation-related AIDs and four IL-15/IL-15R-targeted AID therapies are described.
Animals ; Autoimmune Diseases ; metabolism ; Humans ; Interleukin-15 ; metabolism ; Lupus Erythematosus, Systemic ; metabolism ; Multiple Sclerosis ; metabolism

The aim of this study was to investigate the functional characteristics and in vitro specific killing effect of EGFRvIII CAR-T cells co-expressing interleukin-15 and chemokine CCL19, in order to optimize the multiple functions of CAR-T cells and improve the therapeutic effect of CAR-T cells targeting EGFRvIII on glioblastoma (GBM). The recombinant lentivirus plasmid was obtained by genetic engineering, transfected into 293T cells to obtain lentivirus and infected T cells to obtain the fourth generation CAR-T cells targeting EGFRvIII (EGFRvIII-IL-15-CCL19 CAR-T). The expression rate of CAR molecules, proliferation, chemotactic ability, in vitro specific killing ability and anti-apoptotic ability of the fourth and second generation CAR-T cells (EGFRvIII CAR-T) were detected by flow cytometry, cell counter, chemotaxis chamber and apoptosis kit. The results showed that compared with EGFRvIII CAR-T cells, EGFRvIII-IL-15-CCL19 CAR-T cells successfully secreted IL-15 and CCL19, and had stronger proliferation, chemotactic ability and anti-apoptosis ability in vitro (all P < 0.05), while there was no significant difference in killing ability in vitro. Therefore, CAR-T cells targeting EGFRvIII and secreting IL-15 and CCL19 are expected to improve the therapeutic effect of glioblastoma and provide an experimental basis for clinical trials.
Humans ; Receptors, Chimeric Antigen/metabolism* ; Glioblastoma/metabolism* ; Interleukin-15/metabolism* ; Chemokine CCL19/metabolism* ; Cell Line, Tumor ; T-Lymphocytes/metabolism*

IL-15 and IL-15 receptors (IL-15R) play a crucial role in the pathogenesis of adult T-cell leukemia (ATL), multiple myeloma and inflammatory autoimmune diseases. To develop a novel therapeutic agent capable of eliminating IL-15R-over-expressing abnormal cells, the gene coding for human IL-15 antagonist (IL-15M) was fused with a DNA fragment coding for the mutated form of Pseudomonas exotoxin, PEdelta293. The resulting gene fusion was cloned into pET16b under the control of T7 promoter, giving rise to the expression plasmid pET-IL15M-PEdelta293. Using Ni2+ -NTA affinity chromatography, IL15M-PEdelta293 was purified from E. coli BL21 (DE3) pLysS transformed with pET-IL15M-PEdelta293. The fusion toxin showed cytotoxicity to IL-15R-bearing myelogenous leukemia cell line K562 and K562-derived multidrug resistant cell line K562/AO2. However, IL-15R negative cell line Jurkat was insensitive to IL15M-PEdelta293. In addition, the toxic effect of IL15M-PEdelta293 on K562 was completely blocked by excessive amount of recombinant human IL-15. These results demonstrated that the selective cytotoxicity of IL15M-PEdelta293 correlated with the appropriate IL-15R expression on target cells. The present data suggest that the chimeric toxin constructed in this report may have therapeutic potential in the treatment of diseases associated with abnormal expression of IL-15/IL-15R, even in the treatment of chemotherapy refractory tumors.
Escherichia coli ; genetics ; metabolism ; Exotoxins ; biosynthesis ; genetics ; Genetic Vectors ; genetics ; metabolism ; Humans ; Interleukin-15 ; antagonists & inhibitors ; biosynthesis ; genetics ; K562 Cells ; Pseudomonas aeruginosa ; genetics ; metabolism ; Receptors, Interleukin-15 ; metabolism ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; pharmacology

The aim of this study was to compare cell proliferation and function of the T cells acquired under various culture conditions for establishing a simple, safe and efficient cell expansion protocol in vitro. The peripheral blood mononuclear cells (PBMNC) were isolated and stimulated with autologous dendritic cells (DC) and EBV-transformed B lymphoblastoid cell line (BLCL) weekly. The cell proliferation test, flow cytometry with PI and Annexin V double staining, Cr release test and ELISPOT test were used to detect the cell expansion level, frequency of IFN-γ producing T cells, killing activity of antigen-specific T cells, cell apoptotic status and cell differentiation potential, respectively. The results indicated that use of IL-2 combined with IL-7 and IL-15 resulted in the highest cell expansion comparing to the use of IL-2 alone and the use of CD3/28 Microbeads. Also the cells obtained under cultivating with IL-2, IL-7 and IL-15 together showed high frequency of IFN-γ producing cells, strong killing activity, high viability and high differentiation potential with large portion of CD3(+)CD8(+) population among the T cells. It is concluded that a protocol is established in which the use of IL-2 combined with IL-7 and IL-15 induces the biggest cell expansion, expanded cells show high viability, strong differentiation potential, high frequency of IFN-γ producing cells and strong killing activity.
Cell Line, Transformed ; Cell Proliferation ; Cell Separation ; Dendritic Cells ; cytology ; metabolism ; Humans ; Interleukin-15 ; pharmacology ; Interleukin-2 ; pharmacology ; Interleukin-7 ; pharmacology ; T-Lymphocytes ; cytology ; drug effects ; metabolism

BACKGROUND: Asbestos fibers possess tumorigenicity and are thought to cause mesothelioma. We have previously reported that exposure to asbestos fibers causes a reduction in antitumor immunity. Asbestos exposure in the mixed lymphocyte reaction (MLR) showed suppressed induction of cytotoxic T lymphocytes (CTLs), accompanied by a decrease in proliferation of CD8 METHODS: For MLR, human peripheral blood mononuclear cells (PBMCs) were cultured with irradiated allogenic PBMCs upon exposure to chrysotile B asbestos at 5 μg/ml for 7 days. After 2 days of culture, IL-15 was added at 1 ng/ml. After 7 days of MLR, PBMCs were collected and analyzed for phenotypic and functional markers of CD8 RESULTS: IL-15 addition partially reversed the decrease in CD3 CONCLUSION These findings indicate that CTLs induced upon exposure to asbestos possess dysfunctional machinery that can be partly compensated by IL-15 supplementation, and that IL-15 is more effective in the recovery of proliferation and granzyme B levels from asbestos-induced suppression of CTL induction compared with IL-2.
Asbestos/adverse effects* ; CD8-Positive T-Lymphocytes/metabolism* ; Humans ; Interleukin-15/pharmacology* ; Lymphocyte Activation/immunology* ; T-Lymphocytes, Cytotoxic/metabolism*

OBJECTIVETo explore the expansion method of high purity NK cells from human peripheral blood and explore the changes in biological functions of NK cells after ex vivo expansion.

METHODSNK cells were isolated from peripheral blood mononuclear cells (PBMNCs) by using miniMACS (Magnetic cell-selection) and NK Cell Isolation Kit II, and cultured in SCEM (Stemline Hematopoietic Stem Cell Expansion Medium, Sigma) supplemented with 10% human AB serum and different combinations of interleukin (IL)-2 and/or IL-12, IL-15 for 15 days. Cultures were semi-exchanged with fresh media and cytokines every 3 days. Evaluation for cell expansion, phenotype, perforin and granzyme B mRNA expressions, and IFN-gamma secretion before and after the culture period.

RESULTSCD3(-) CD56(+) cells concentration increased from (11.2 +/- 5.2)% to (94.2 +/- 3.5)%. In group IL-2 + IL-15 and IL-2 + IL-15 + IL-12 group, cells were expanded 50.5 +/- 4.3 and 52.3 +/- 6.7 - fold, respectively, being significantly higher than that in other three groups [(15.4 +/- 1.1 fold in IL-2 group, 19.9 +/- 3.9 fold in IL-2 + IL-12 group, 6.1 +/- 1.0 fold in control group)] (P<0.01), but no significant difference between each other (P>0.05). The purity of CD3(-) CD56(+) NK cells was over 94% in all groups except the control. The perforin and granzyme B mRNA expressions of expanded NK cells in four experimental groups were significantly higher than those of before expansion (P<0.01) and the expressions in IL-2 + IL-15 and in IL-2 + IL-12 + IL-15 group were significant higher than in other three groups (P<0.01) while no significant difference between each other (P>0.05). IFN-gamma levels in the supernatants of four experiment groups were significantly higher than that in control group (P<0.01) and its levels order was IL-2 + IL-15 + IL-12 group > IL-2 + IL-12 group > IL-2 + IL-15 group > IL-2 group (P<0.01).

CONCLUSIONHigh purity NK cells isolated by negative selection using miniMACS can be efficiently expanded with IL-2 + IL-15, and their biological functions were enhanced.

Cell Culture Techniques ; Cell Proliferation ; Cell Separation ; Cells, Cultured ; Granzymes ; metabolism ; Humans ; Interferon-gamma ; metabolism ; Interleukin-12 ; pharmacology ; Interleukin-15 ; pharmacology ; Interleukin-2 ; pharmacology ; Interleukins ; pharmacology ; Killer Cells, Natural ; cytology ; drug effects ; immunology ; metabolism ; Perforin ; metabolism

This study was aimed to investigate the effects of different stimulatory factors on proliferation and function of cytokine induced killer (CIK) cells. Peripheral blood mononuclear cells (PBMNC) were separated by Ficoll-Hypacue gradient. According to supplement of different stimulatory factors (CD28 mAb, IL-15 and IL-21), the experiment was divided into five groups:control group (CIK), CB28+IL-15+IL-21 group, IL-15+IL-21 group, CD28+IL-15 group and CD28+IL-21 group. Effects of different stimulatory factors on the proliferation of CIK cells were assayed by an automated hematology analyzer. Changes of granzyme B,perforin and CD107a were detected by flow cytometry. IL-10, IL-12, INF-γ and TNF-α were quantified by ELISA. Cytotoxicities on lung cancer cell line A549, breast adenocarcinoma cell line MFC-7 and human melanoma cell line HME1 were examined by lactate dehydrogenase release method. The results showed that there were significant differences among different groups. The highest proliferation index on days 10 was observed in group CD28mAb, IL-15 and IL-21(255.3 ± 6.3), which was higher than control group, IL-21+IL-15 group and CD28 mAb+IL-21 group (166.6 ± 13.5, 199.4 ± 15.0 and 228.8 ± 16.6) (P < 0.05). The expression of perforin in CD28 mAb+IL-15 group was higher than the other groups. The expression of perforin,GranB and CD107a of costimulatory groups was higher than control group. The cytotoxicities of CD28 mAb+IL-15 group on A549, MFC-7 and HME1 cells (82.2%, 59.3% and 70.6%) were much higher than that of control group (60.9%, 49.6% and 48.4%) (P < 0.05). The highest IFN-γsecretion was found in CD28 mAb, IL-15 and IL-21 groups. It is concluded that there are significant difference of proliferative capacity, cytokine secretion and cytotoxicity after being activated by different stimulatory factors. Adding corresponding stimulatory factors into the culture system displays a great value for target cells culture.
Cell Line, Tumor ; Cell Proliferation ; drug effects ; Cytokine-Induced Killer Cells ; cytology ; drug effects ; Humans ; Interferon-gamma ; metabolism ; Interleukin-10 ; metabolism ; Interleukin-12 ; metabolism ; Interleukin-15 ; pharmacology ; Interleukins ; pharmacology ; Tumor Necrosis Factor-alpha ; metabolism

OBJECTIVETo obtain streptavidin-tagged human interleukin-15 (SA/hIL15) fusion protein and evaluate its bioactivity.

METHODSpET24a-6His-SA-hIL-15 and pET32a-hIL-15-SA-6His plasmids were constructed and expressed in BL 21(DE3) host bacteria to generate the fusion protein. The recombinant fusion protein IL-15/SA was purified using Ni-NTA affinity chromatography and refolded, and the efficiency of surface modification of the fusion protein on biotinylated cells was examined by fluorescence-activated cell sorting. CCK-8 method was used to evaluate the effect of IL-15/SA fusion protein in inducing the proliferation of human peripheral-blood lymphocyte (PBL) cells stimulated by PHA.

RESULTSThe recombinant SA-hIL-15 and hIL15-SA fusion proteins were highly expressed in BL21(DE3) at about 20% of the total bacterial proteins. The purified hIL15-SA fusion protein exhibited a bifunctionality by promoting the proliferation of PBL cells activated by PHA and high-affinity binding to biotinylated cell surface mediated by SA, with a cell surface modification efficiency exceeding 95%. SA-hIL-15 showed a 4-fold higher hIL15 bioactivity than hIL15-SA.

CONCLUSIONSA/hIL-15 bifunctional fusion protein has been successfully obtained to facilitate the future development of hIL-15-surface-modified cancer cell vaccine.

Cancer Vaccines ; genetics ; immunology ; Escherichia coli ; genetics ; metabolism ; Genetic Vectors ; Humans ; Interleukin-15 ; biosynthesis ; genetics ; Lymphocyte Activation ; drug effects ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; immunology ; Streptavidin ; biosynthesis ; genetics