Therapeutic and specific antitumor immunity induced by co-administration of immature dendritic cells and adenoviral vector expressing biologically active IL-18

Interleukin-18 is a potent cytokine expressed early in the immune response following cleavage in activated composes. We have investigated the in vivo antitumor effects of intratumoral (i.t.) administration of an adenoviral vector expressing biologically active murine interleukin (IL)-18 (Ad.PTH.IL-18). Substantial antitumor effects were observed when established MCA205 fibrosarcoma was treated in syngeneic immunocompetent mice with intratumoral injection of Ad.PTH.IL-18 (P = 0.0025 versus control vector treatment), generating potent cytotoxic T lymphocytes (CTLs) in culture. In contrast, the antitumor effect was absent, and cytotoxic activity was significantly less (P = 0.021) in gld mice (Fas ligand deficient). To enhance the in vivo antitumor activity of the treatment using Ad.PTH.IL-18, we co-injected immature DC and Ad.PTH.IL-18 i.t. into established, day 7 MCA205 fibrosarcoma and MC38 adenocarcinoma. Co-injection of both Ad.PTH.IL-18 and DC was associated with complete abrogation of injected tumors. Furthermore, the antitumor effects were also observed on distant tumors inoculated i.d. in the contralateral flank of the animal. The induced cytolytic activity was tumor-specific and MHC class I-restricted. As we have previously demonstrated in vitro (Tanaka F et al, Cancer Res 2000; 60: 4838-4844) and consistent with these findings in vivo, NK, T and dendritic cells coactivately mediate the IL-18 enhanced antitumor effect. This study suggests that the coactivate strategy could be used in the clinical setting to treat patients with cancer. do     

Antitumor activity of interleukin-18 against the murine T-cell leukemia/lymphoma EL-4 in syngeneic mice

Interleukin (IL)-18 induces interferon (IFN)-gamma production by T cells and natural killer (NK) cells, and augments NK cell activity in mouse spleen cell cultures. It has recently been demonstrated that in vivo administration of IL-18 to mice results in considerable antitumor effects against syngeneic Meth A sarcoma. In this study, the antitumor effects of IL-18 against murine T-cell leukemia (EL-4) were evaluated. EL-4 proliferation was resistant in vitro to IL-18 and IFN-gamma. When 4 x 10(6) EL-4 cells were transplanted intravenously, the antitumor effects of IL-18 were not pronounced, and only a slight prolongation of the mean survival times was observed. The antitumor effects of IFN-gamma were even less apparent than those of IL-18. However, when mice were transplanted intravenously with 5 x 10(5) EL-4 cells, the extent of experimental visceral dissemination of EL-4 was markedly reduced in mice treated subcutaneously with IL-18, resulting in an increase in survival time with some mice even cured. Although IL-18 was highly effective at inhibiting the development of EL-4 lymphoma dissemination in C57BL/6 mice, it could not inhibit the development of dissemination in mutant C57BL/6 beige (bg/bg) mice lacking NK cell activity. The efficacy of IL-18 was also significantly reduced in nude mice lacking T cells. These results suggest that antitumor efficacy of IL-18 is mediated primarily by NK cells, but that T cells are also required for the complete antitumor efficacy of IL-18.     

IL-2和IL-15激活供者自然杀伤细胞在异基因造血干细胞移植应用的实验研究

目的 探讨IL-2和IL-15激活的供者自然杀伤(NK)细胞在异基因造血干细胞移植(allo-HSCT)中减轻移植物抗宿主病(GVHD)发挥移植物抗白血病效应方面的作用.方法 采用免疫磁珠分选小鼠脾NK细胞,采用添加IL-2和IL-15的培养基扩增NK细胞并测定NK细胞杀伤活力.C57BL/6小鼠作为供鼠,BALB/c小鼠作为受鼠,部分小鼠移植前8天静脉接种EL9611白血病细胞.异基因移植小鼠输注骨髓细胞5×106 和脾细胞5 × 106.NK细胞治疗组输注骨髓细胞和脾细胞各5×106 以及激活的NK细胞1 × 107,并且给予腹腔注射IL-2和IL-15.移植后观察GVHD发生、生存期、嵌合度、免疫重建.结果 分选NK细胞纯度为95.7%～97.1%.培养后NK细胞杀伤活力较静息时增加3倍.单纯异基因骨髓细胞输注组小鼠未见GVHD发生,异基因骨髓及脾细胞移植对照组移植后1周起开始出现GVHD表现.实验组小鼠发生GVHD的严重程度明显低于脾细胞输注小鼠(P＜0.05).单纯全身照射预处理小鼠生存期9.5～14.0 d.白血病模型中对照组移植后100 d生存率10%,其余死于白血病;实验组80%生存期超过100 d,实验组生存期明显长于对照组(P＜0.01).实验组小鼠移植后2周外周血NK细胞占4.8%,对照组外周血NK细胞占2.8%,实验组NK细胞恢复早于对照组(P＜0.05).实验组TRBV基因重建比对照组快,而且TRBV家族基因表达数比对照组多,对照组小鼠多见单克隆及寡克隆表达.结论 IL-2和IL-15在体外可以有效促进NK细胞增殖与激活.allo-HSCT时给予激活的供者NK细胞输注以及相关细胞因子处理可以促进免疫重建、减轻GVHD发生、降低白血病复发.     

白细胞介素12单独或联合白细胞介素2对人脐血单个核细胞抗肿？…

目的 探讨白细胞介素１２（ＩＬ－１２）单独或联合白细胞介素２（ＩＬ－２）对人脐血单个核细胞（ＣＲＭＣ）抗肿瘤作用的影响。方法 采用＾３Ｈ－ＴｄＲ释放法测定经ＩＬ－１２和（或）ＩＬ－２刺激的ＣＢＭＣ和人外周血单个核细胞（ＰＢＭＣ）的抗肿瘤活性,及在电镜下观察激活的ＣＢＭＣ所杀伤的Ｋ５６２细胞的形态特征。结果 ①ＩＵ／ｍｌＩＬ－１２激活的ＧＢＭＣ即产生较强的杀伤活性,对Ｋ５６２及Ｒａｊｉ细胞的杀伤率分     

白细胞介素2基因和白细胞介素3基因共转染白血病瘤苗的抗白…

目的：研究白细胞介素２（ＩＬ－２）和白细胞介素３（ＩＬ－３）基因共转染的白血病细胞瘤苗对白血病的小鼠的治疗效果。方法：用ＩＬ－２重组腺病毒（Ａｄ－ＩＬ－２）和（或）ＩＬ－３重组腺病毒转染红白轿病细胞株ＦＢＬ－３，＾６０Ｃｏ射后制备成瘤苗对实验性白血病小鼠进行治疗，观察肿瘤生长，小鼠生存期及治疗后小鼠腹腔巨噬细胞，ＮＫ细胞，诱导杀伤性Ｔ淋巴细胞（ＣＴＬ）杀伤活性，并与低剂量环磷酰胺合用，观察其抗肿瘤     

Local IL-21 Promotes the Therapeutic Activity of Effector T cells by Decreasing Regulatory T Cells Within the Tumor Microenvironment

The eradication of tumors by the immune system depends on the generation of antigen-specific T cells which can migrate to sites of tumor growth and maintain their effector functions despite local tumor-derived T-cell inhibitory factors. Interleukin-21 (IL-21) is an IL-2-related cytokine that has shown limited evidence of antitumor activity in murine models and early phase clinical trials. Effect of local IL-21 on T-cell responses within the tumor microenvironment, however, has not been extensively evaluated. Thus, we developed a stably transfected IL-21-secreting B16 melanoma cell line to test the effects of local IL-21 on endogenous and adoptively transferred T-cell responses. Tumors expressing IL-21 exhibited delayed growth in vivo, which was associated with an increase in activated systemic effector and memory CD8⁺ T–cell responses. Local IL-21 also enhanced the therapeutic effects of adoptively transferred gp100-specific T cells and was synergistic with IL-2. The effect was also associated with an increased proliferation of local CD8⁺ T cells and decreased accumulation of regulatory CD4⁺FOXP3⁺ T cells within the tumor microenvironment. These data suggest that local IL-21 enhances endogenous and adoptively transferred T-cell immunity through increased effector CD8⁺ T cells and decreased CD4⁺ regulatory T cells in the tumor microenvironment.     

ABT-263 and rapamycin act cooperatively to kill lymphoma cells in vitro and in vivo

ABT-263 is a potent, orally bioavailable inhibitor of the antiapoptotic Bcl-2 family members Bcl-2, Bcl-x(L), and Bcl-w, which is currently in phase I clinical trials. Previous work has shown that this compound has low nanomolar cell-killing activity in a variety of lymphoma and leukemia cell lines, many of which overexpress Bcl-2 through a variety of mechanisms. Rapamycin is a macrolide antibiotic that inhibits the mammalian target of rapamycin complex, leading to cell cycle arrest and inhibition of protein translation. Rapamycin (and its analogues) has shown activity in a variety of tumor cell lines primarily through induction of cell cycle arrest. Activity has also been shown clinically in mantle cell lymphoma and advanced renal cell carcinoma. Here, we show that treatment of the follicular lymphoma lines DoHH-2 and SuDHL-4 with 100 nmol/L rapamycin induces substantial G(0)-G(1) arrest. Addition of as little as 39 nmol/L ABT-263 to the rapamycin regimen induced a 3-fold increase in sub-G(0) cells. Combination of these agents also led to a significant increase in Annexin V staining over ABT-263 alone. In xenograft models of these tumors, rapamycin induced a largely cytostatic response in the DoHH-2 and SuDHL-4 models. Coadministration with ABT-263 induced significant tumor regression, with DoHH-2 and SuDHL-4 tumors showing 100% overall response rates. Apoptosis in these tumors was significantly enhanced by combination therapy as measured by staining with an antibody specific for cleaved caspase-3. These data suggest that combination of ABT-263 and rapamycin or its analogues represents a promising therapeutic strategy for the treatment of lymphoma.     

白细胞介素2激活的骨髓及脐血单个核细胞体外抗肿瘤活性的…

目的：比较白细胞介素２激活的骨髓及脐血单个核细胞的抗肿瘤活性性，并探讨其其杀伤机制。方法：采用＾３Ｈ－ＴｄＲ前标记释放法和半固体培养等方法研究ＩＬ－２激活的骨髓和脐血的单个核细胞对白血病细胞株ＨＬ－６０细胞Ｋ５６２细胞的抗肿瘤活及ＡＢＭ和ＡＣＢ的造血社细胞活性。     

Humanized anti-human IL-6 receptor antibody, tocilizumab

Interleukin-6 (IL-6) is a multifunctional cytokine that regulates immune response and inflammatory reaction. IL-6 has been shown to play pathological roles in the autoimmune reaction, inflammation, and joint destruction in rheumatoid arthritis, and, therefore, an agent blocking IL-6 actions can be a therapeutics of the disease. Tocilizumab is a humanized anti-human IL-6 receptor antibody designed using genetic engineering technology and the first therapeutic monoclonal antibody developed in Japan. Tocilizumab specifically blocks IL-6 actions and ameliorates the diseases with IL-6 overproduction. It has been clinically developed for rheumatoid arthritis and shown to be effective not only for improving signs and symptoms but also for preventing joint destruction of the disease. In this chapter, immunopharmacology and clinical utility of tocilizumab in rheumatoid arthritis is addressed.     

T cell regulation of natural killer cells

In light of their role in the immune response against tumors and viruses, natural killer (NK) cells represent a promising target for immunotherapy. Before this target is reached, the various mechanisms that control NK cell activity must first be identified and understood. In the past decades, studies have identified two critical processes that prevent spontaneous NK cell–mediated autoimmune activation while maximizing the efficiency of these cells during an immune response. First is the education process, whereby NK cells adapt to their environment by sensing ligands for inhibitory and activating receptors. Second is the priming phase of NK cell activation, which arms NK cells with appropriate cytotoxic molecules during inflammation. New studies now indicate that NK cell proliferation, accumulation, and activation are also under the control of regulatory T cells that restrict availability of IL-2 released by activated CD4⁺ T cells. Together with other recent studies, these data highlight the importance of the adaptive immune system in the regulation of NK cell activity.With more than 200 clinical trials involving NK cells over the last decade, it is clear that these cells represent a promising tool in immunotherapy with a strong emphasis on cancer (Vivier et al., 2012). Indeed, many studies in mice have highlighted the potential of NK cells to eradicate developing as well as established tumors of various origins. Their antitumor potential has also been highlighted in humans in the context of hematopoietic stem cell transplantation for acute myeloid leukemia. Despite the fact that genetic depletion models have only recently become available, and that cases of human NK cell deficiencies are rare, a large body of work has demonstrated that this innate immune cell population is also critical in the control of several viral, bacterial, and parasitic infections. Nevertheless, like many other immune cell types, NK cells can also be detrimental for the host and can contribute to the development of immune disorders. The most compelling evidence of a “dark side” for NK cells comes from studies supporting a role for pancreas-infiltrating NK cells in the development of type-1 diabetes (Feuerer et al., 2009). To develop successful NK cell–based therapies, it is critical to clearly understand how their activity is regulated. New data adds to this understanding by showing how regulatory T (T reg) cells and effector CD4⁺ T cells team up to control NK cell activation.     

AZD7762, a novel checkpoint kinase inhibitor, drives checkpoint abrogation and potentiates DNA-targeted therapies

Insights from cell cycle research have led to the hypothesis that tumors may be selectively sensitized to DNA-damaging agents resulting in improved antitumor activity and a wider therapeutic margin. The theory relies on the observation that the majority of tumors are deficient in the G1-DNA damage checkpoint pathway resulting in reliance on S and G2 checkpoints for DNA repair and cell survival. The S and G2 checkpoints are regulated by checkpoint kinase 1, a serine/threonine kinase that is activated in response to DNA damage; thus, inhibition of checkpoint kinase 1 signaling impairs DNA repair and increases tumor cell death. Normal tissues, however, have a functioning G1 checkpoint signaling pathway allowing for DNA repair and cell survival. Here, we describe the preclinical profile of AZD7762, a potent ATP-competitive checkpoint kinase inhibitor in clinical trials. AZD7762 has been profiled extensively in vitro and in vivo in combination with DNA-damaging agents and has been shown to potentiate response in several different settings where inhibition of checkpoint kinase results in the abrogation of DNA damage-induced cell cycle arrest. Dose-dependent potentiation of antitumor activity, when AZD7762 is administered in combination with DNA-damaging agents, has been observed in multiple xenograft models with several DNA-damaging agents, further supporting the potential of checkpoint kinase inhibitors to enhance the efficacy of both conventional chemotherapy and radiotherapy and increase patient response rates in a variety of settings.     

Association of single nucleotide polymorphisms in IL-12 and IL-27 genes with colorectal cancer risk

ObjectivesInterleukin-12 (IL-12) plays an important role in antitumor immunity. Interleukin-27 (IL-27) is a novel IL-12 family member. The present studies demonstrate that IL-27 mediates potent antitumor activity. However, No studies have examined the association of these polymorphism with colorectal cancer (CRC). Therefore, we investigated the relationship of IL-12 and IL-27 gene polymorphisms and CRC.Design and methodsWe analyzed polymorphisms of IL-12 gene 16974 A/C and IL-27 gene ? 964 A/G, 2905 T/G, 4730 T/C in 410 patients with CRC and 450 controls, using PCR-RFLP method.ResultsThere were no significant differences in the genotype and allele frequencies of IL-12 and IL-27 gene polymorphisms between the group of patients with CRC and the controls. Furthermore, no association was found between IL-12 family gene polymorphisms and different clinical stages in patients with CRC.ConclusionThese findings suggest that IL-12 and IL-27 gene polymorphisms may not be involved in susceptibility to CRC.     

Antitumor and antimetastatic activity of interleukin 12 against murine tumors

It has recently been demonstrated that in vivo administration of murine interleukin 12 (IL-12) to mice results in augmentation of cytotoxic natural killer (NK)/lymphocyte-activated killer cell activity, enhancement of cytolytic T cell generation, and induction of interferon gamma secretion. In this study, the in vivo activity of murine IL-12 against a number of murine tumors has been evaluated. Experimental pulmonary metastases or subcutaneous growth of the B16F10 melanoma were markedly reduced in mice treated intraperitoneally with IL-12, resulting in an increase in survival time. The therapeutic effectiveness of IL-12 was dose dependent and treatment of subcutaneous tumors could be initiated up to 14 d after injection of tumor cells. Likewise, established experimental hepatic metastases and established subcutaneous M5076 reticulum cell sarcoma and Renca renal cell adenocarcinoma tumors were effectively treated by IL-12 at doses which resulted in no gross toxicity. Local peritumoral injection of IL-12 into established subcutaneous Renca tumors resulted in regression and complete disappearance of these tumors. IL-12 was as effective in NK cell-deficient beige mice or in mice depleted of NK cell activity by treatment with antiasialo GM1, suggesting that NK cells are not the primary cell type mediating the antitumor effects of this cytokine. However, the efficacy of IL-12 was greatly reduced in nude mice suggesting the involvement of T cells. Furthermore, depletion of CD8+ but not CD4+ T cells significantly reduced the efficacy of IL-12. These results demonstrate that IL-12 has potent in vivo antitumor and antimetastatic effects against murine tumors and demonstrate as well the critical role of CD8+ T cells in mediating the antitumor effects against subcutaneous tumors.     

Oncolytic adenovirus co-expressing IL-12 and IL-18 improves tumor-specific immunity via differentiation of T cells expressing IL-12Rβ2 or IL-18Rα

The oncolytic adenovirus (Ad) is currently being advanced as a promising antitumor remedy as it selectively replicates in tumor cells and can transfer and amplify therapeutic genes. Interleukin (IL)-12 induces a potent antitumor effect by promoting natural killer (NK) cell and cytotoxic T cell activities. IL-18 also augments cytotoxicity of NK cells and proliferation of T cells. This effect further enhances the function of IL-12 in a synergistic manner. Therefore, we investigated for the first time an effective cancer immunogene therapy of syngeneic tumors via intratumoral administration of oncolytic Ad co-expressing IL-12 and IL-18, RdB/IL-12/IL-18. Intratumoral administration of RdB/IL-12/IL-18 improved antitumor effects, as well as increased survival, in B16-F10 murine melanoma model. The ratio of T-helper type 1/2 cytokine as well as the levels of IL-12, IL-18, interferon-γ and granulocyte-macrophage colony-stimulating factor was markedly elevated in RdB/IL-12/IL-18-treated tumors. Mice injected with RdB/IL-12/IL-18 also showed enhanced cytotoxicity of tumor-specific immune cells. Consistent with these results, immense necrosis and infiltration of NK cells, as well as CD4+ and CD8+ T cells, were observed in RdB/IL-12/IL-18-treated tumor tissues. Importantly, tumors treated with RdB/IL-12/IL-18 showed an elevated number of T cells expressing IL-12Rβ2 or IL-18Rα. These results provide a new insight into therapeutic mechanisms of IL-12 plus IL-18 and provide a potential clinical cancer immunotherapeutic agent for improved antitumor immunity.     

Low-dose adenoviral immunotherapy of rat hepatocellular carcinoma using single-chain interleukin-12

Generation of antitumor immunity by adenoviral gene transfer of interleukin-12 (IL-12) is a very promising concept in cancer gene therapy. Systemically, IL-12 has provoked toxic side effects at therapeutically relevant doses. Native IL-12 lacks effectiveness in clinical trials even when expressed intratumorally from adenoviral vectors. Our strategy was to increase the therapeutic efficacy of IL-12 by expressing a fusion protein of its two subunits (scIL-12) in an adenoviral vector and to evaluate the effects after intratumoral administration. In a rat model of hepatocellular carcinoma, this vector revealed antitumor effects even at a low dosage of 4.6 x 10(5) i.u. in a dose-dependent manner. Long-term antitumor effects were determined at 2.3 x 10(6) and 2.3 x 10(7) i.u. per animal, resulting in 82% and 90% surviving animals, respectively. Magnetic resonance imaging (MRI) enabled individual tumor size follow-up and revealed the scIL-12 effects on large tumors. Treating one hepatic lesion also led to tumor elimination in a second non-treated hepatic lesion. Animals rechallenged with tumor cells remained tumor-free. Compared to studies applying native IL-12, our data show that the fusion of IL-12 subunits provides approximately 1000-fold higher biological activity. As a consequence of the observed gain in activity, scIL12 promises a substantially improved antitumor efficacy and safety profile of intratumoral adenoviral IL-12 immunotherapy, supporting its clinical use.     

Systemic administration of rIL-12 synergistically enhances the therapeutic effect of a TNF gene-transduced cancer vaccine

Interleukin-12 (IL-12) is a potent antitumor cytokine, which induces and enhances the activity of natural killer (NK) cells, lymphokine activated killer (LAK) cells and cytotoxic T lymphocytes (CTL). IL-12 also stimulates IFN-gamma production from both T cells and NK cells. In this study, we transfected methylcholanthrene-induced fibrosarcoma (MCA-D) with TNF gene and investigated the therapeutic effect of TNF gene-transduced cancer vaccine and whether the vaccination effect is enhanced by systemic administration of recombinant IL-12 (rIL-12), in a murine model. TNF gene-transduced cancer vaccine or systemic administration of rIL-12 showed slight or moderate inhibition of pre-established tumor. However, simultaneous application of the vaccine and rIL-12 resulted in complete eradication. The cytotoxicity of CTL against parental tumor cells was enhanced with the combination of the vaccine and rIL-12, and IFN-gamma production from spleen cells also increased synergistically. Our findings show that synergistic enhancement of CTL activity and IFN-gamma production could play an important role in the antitumor effect of combination therapy using TNF gene-transduced cancer vaccine and rIL-12.     

Specifically targeted killing of interleukin-13 (IL-13) receptor-expressing breast cancer by IL-13 fusion cytotoxin in animal model of human disease

Interleukin-13 receptor (IL-13R) alpha2 chain binds IL-13 with high affinity and can internalize after binding to ligand. We have exploited this property of IL-13Ralpha2 chain by receptor-targeted breast cancer therapy. Previous studies have demonstrated that in vivo intratumoral (i.t.) gene transfer of this chain followed by IL-13 cytotoxin [comprised of IL-13 and Pseudomonas exotoxin (IL13-PE38QQR)] therapy causes regression of established human tumors in xenografted models. Breast carcinoma cells do not express IL-13Ralpha2 chain and are resistant to the antitumor effect of IL-13 cytotoxin. To determine whether IL-13Ralpha2 chain can render sensitivity of breast cancer to IL-13 cytotoxin, we injected IL-13Ralpha2 plasmid in s.c. established tumors by i.t. route, followed by systemic or i.t. IL-13 cytotoxin administration. This combination approach showed profound antitumor activity against human breast tumors in xenografted immunodeficient mice. Interestingly, there was dominant infiltration of inflammatory cells in regressing tumors, which were identified to be macrophages producing nitric oxide (NO) and natural killer cells. The partial role of inducible nitric oxide synthase (iNOS)-positive macrophages was confirmed by in vivo macrophage depletion experiments. Serum chemistry, hematology, and organ histology from treated mice did not show any remarkable toxicity resulting from the combination therapy. Taken together, local gene transfer of IL-13Ralpha2 followed by receptor-targeted IL-13 cytotoxin therapy may be applied safely and effectively to the treatment of localized breast cancer.     

Cancer Immunotherapy Using a Membrane-bound Interleukin-12 With B7-1 Transmembrane and Cytoplasmic Domains

Interleukin-12 (IL-12) has potent antitumor activity, but its clinical application is limited by severe systemic toxicity, which might be alleviated by the use of membrane-anchored IL-12. In the present study, a new membrane-bound IL-12 containing murine single-chain IL-12 and B7-1 transmembrane and cytoplasmic domains (scIL-12-B7TM) was constructed and its efficacy in cancer treatment examined and its protective antitumor mechanism investigated. Surface expression of scIL-12-B7TM on colon adenocarcinoma cells significantly inhibited the growth of subcutaneous tumors, suppressed lung metastasis, and resulted in local and systemic suppression of unmodified tumors. Intratumoral injection of an adenoviral vector encoding scIL-12-B7TM not only resulted in complete regression of a majority of local tumors, but also significantly suppressed the growth of distant, untreated tumors. Moreover, mice that had been treated with scIL-12-B7TM developed memory responses against subsequent tumor challenge. Immunohistochemical staining and in vivo depletion of lymphocyte subpopulations demonstrated that both CD8⁺ T cells and CD4⁺ T cells contributed to the antitumor activity of scIL-12-B7TM. Importantly, the potent antitumor activities of scIL-12-B7TM were achieved with only negligible amounts of IL-12 in the circulation. Our data demonstrate that cancer immunotherapy using membrane-bound IL-12 has the advantage of minimizing systemic IL-12 levels without compromising its antitumor efficacy.     

IL-12 upregulates TIM-3 expression and induces T cell exhaustion in patients with follicular B cell non-Hodgkin lymphoma

The cytokine IL-12 induces IFN-γ production by T and NK cells. In preclinical models, it contributes to antitumor immunity. However, in clinical testing, it has shown limited benefit in patients with any one of a variety of malignancies. Moreover, in a clinical trial testing a combination of IL-12 and rituximab in patients with follicular B cell non-Hodgkin lymphoma (FL), those treated with IL-12 showed a lower response rate, suggesting that IL-12 actually plays a detrimental role. Here, we investigated whether the failure of IL-12 treatment for FL was due to T cell exhaustion, a condition characterized by reduced T cell differentiation, proliferation, and function, which has been observed in chronic viral infection. We found that extended exposure to IL-12 induced T cell exhaustion and contributed to the poor prognosis in FL patients. Long-term exposure of freshly isolated human CD4+ T cells to IL-12 in vitro caused T cell dysfunction and induced expression of TIM-3, a T cell immunoglobulin and mucin domain protein with a known role in T cell exhaustion, via an IFN-γ-independent mechanism. TIM-3 was required for the negative effect of IL-12 on T cell function. Importantly, TIM-3 also was highly expressed on intratumoral T cells that displayed marked functional impairment. Our findings identify IL-12- and TIM-3-mediated exhaustion of T cells as a mechanism for poor clinical outcome when IL-12 is administered to FL patients.     

GITRL联合IL-21基因真核表达载体的构建及体外研究

本研究构建人糖皮质激素诱导的肿瘤坏死因子受体配体（GITRL）联合白介素-21（IL-21）基因真核表达载体,为探讨目的基因对慢性髓系白血病（CML）来源树突状细胞（DC）的影响.应用脂质体介导法将重组真核表达载体转染至纯化的DC,而此纯化的DC来源于经伊马替尼治疗有效或无效的慢性期CML患者或健康志愿者.应用ELISA法检测转染后DC细胞因子的浓度变化.将转染后的DC与纯化的自体NK混合培养使之成为DC-CIK.以DC-CIK细胞为效应细胞,应用乳酸脱氢酶释放法观察其对靶细胞的杀伤率.结果表明：所获目的基因经测序 与GenBank比对序列一致,PCR及限制性核酸内切酶检测显示,真核表达载体质粒经限制性酶切鉴定片段大小正确,并均可转染至伊马替尼治疗有效、无效的慢性期CML患者及健康志愿者来源的DC细胞.成功转染相应载体后的DC分别表现出IL-2和IFN-γ分泌量增加;细胞毒活性试验表明,转染后的DC可增加自体NK细胞对K562细胞的杀伤活性.结论：DC能够通过转染IL-21和GITRL基因的方式获得自我活化、上调自身细胞因子分泌的能力,为酪氨酸激酶抑制剂治疗无效的CML患者的免疫治疗奠定了理论依据和实验基础.