树突细胞联合细胞因子诱导的杀伤细胞对急性白血病细胞的体外杀伤作用

目的:研究细胞因子诱导的杀伤细胞(CIK)与同源树突状细胞(DC)共培养后CIK细胞的表型、增殖活性的变化,及抗急性白血病细胞活性.方法:正常人外周血单个核细胞诱导DC和CIK细胞,将DC与CIK共培养,以CIK细胞单独培养为对照.用台盼蓝活细胞计数计算细胞扩增倍数,MTT法测定杀伤活性,流式细胞术分析免疫表型.结果:DC-CIK细胞增殖能力明显高于CIK细胞(P＜0.05); DC、CIK细胞共培养后,CD3+ CD8+、CD3+ CD56+双阳性细胞比率较同条件下CIK细胞组显著增多(P＜0.05);在2.5∶1-20∶1的效靶比范围内,DC-CIK共培养物对AML细胞的杀伤率显著高于CIK细胞(P＜0.05),且杀伤率与效靶比呈正相关.结论:DC-CIK细胞的增殖能力、对AML细胞的杀伤活性均高于CIK细胞,为DC-CIK细胞免疫治疗提供了实验和理论依据.     

Sunitinib Indirectly Enhanced Anti-Tumor Cytotoxicity of Cytokine-Induced Killer Cells and CD3+CD56+ Subset through the Co-Culturing Dendritic Cells

Cytokine-induced killer (CIK) cells have reached clinical trials for leukemia and solid tumors. Their anti-tumor cytotoxicity had earlier been shown to be intensified after the co-culture with dendritic cells (DCs). We observed markedly enhanced anti-tumor cytotoxicity activity of CIK cells after the co-culture with sunitinib-pretreated DCs over that of untreated DCs. This cytotoxicity was reliant upon DC modulation by sunitinib because the direct exposure of CIK cells to sunitinib had no significant effect. Sunitinib promoted Th1-inducing and pro-inflammatory phenotypes (IL-12, IFN-γ and IL-6) in DCs at the expense of Th2 inducing phenotype (IL-13) and regulatory phenotype (PD-L1, IDO). Sunitinib-treated DCs subsequently induced the upregulation of Th1 phenotypic markers (IFN-γ and T-bet) and the downregulation of the Th2 signature (GATA-3) and the Th17 marker (RORC) on the CD3⁺CD56⁺ subset of CIK cells. It concluded that sunitinib-pretreated DCs drove the CD3⁺CD56⁺ subset toward Th1 phenotype with increased anti-tumor cytotoxicity.     

Autologous Tumor Lysate-Pulsed Dendritic Cell Immunotherapy with Cytokine-Induced Killer Cells Improves Survival in Gastric and Colorectal Cancer Patients

Gastric and colorectal cancers (GC and CRC) have poor prognosis and are resistant to chemo- and/or radiotherapy. In the present study, the prophylactic effects of dendritic cell (DC) vaccination are evaluated on disease progression and clinical benefits in a group of 54 GC and CRC patients treated with DC immunotherapy combined with cytokine-induced killer (CIK) cells after surgery with or without chemo-radiotherapy. DCs were prepared from the mononuclear cells isolated from patients using IL-2/GM-CSF and loaded with tumor antigens; CIK cells were prepared by incubating peripheral blood lymphocytes with IL-2, IFN-γ, and CD3 antibodies. The DC/CIK therapy started 3 days after low-dose chemotherapy and was repeated 3–5 times in 2 weeks as one cycle with a total of 188.3±79.8×10⁶ DCs and 58.8±22.3×10⁸ CIK cells. Cytokine levels in patients'' sera before and after treatments were measured and the follow-up was conducted for 98 months to determine disease-free survival (DFS) and overall survival (OS). The results demonstrate that all cytokines tested were elevated with significantly higher levels of IFN-γ and IL-12 in both GC and CRC cohorts of DC/CIK treated patients. By Cox regression analysis, DC/CIK therapy reduced the risk of post-operative disease progression (p<0.01) with an increased OS (<0.01). These results demonstrate that in addition to chemo- and/or radiotherapy, DC/CIK immunotherapy is a potential effective approach in the control of tumor growth for post-operative GC and CRC patients.     

重组人纤维蛋白片段诱导CIK的增殖及对肺癌耐顺铂细胞的杀伤作用

为探讨重组人纤维蛋白片段(RetroNectin)对CIK(Cytokine-induced killer cells)细胞活化、增殖的影响及CIK细胞的免疫学特性和对肺癌耐药细胞DDP-A549 (DDP: Cisplatin)的杀伤作用。提取健康人外周血中单个核细胞, Ⅰ组细胞接种于前一天用RetroNectin和CD3MAb包被好的培养瓶中, Ⅱ组接种于单独用CD3MAb包被好的培养瓶中, 接种当天加入IFN-γ, 第二天加入IL-2诱导CIK细胞。细胞计数法测定CIK细胞的增殖,并绘制细胞生长曲线, MTT法测定细胞杀伤活性,流式细胞术分析细胞表型。扫描电镜和透射电镜下观察CIK细胞对DDP-A549的杀伤和DDP-A549细胞的改变。RetroNectin对CIK细胞有很强的激活作用, 可使其细胞增殖总数达524.77倍, 其主要效应细胞CD3+CD56+可达(31.40±1.91)%; 对肺癌耐顺铂细胞DDP-A549的杀伤作用明显高于其亲代药物敏感株A549(P<0.01)。但两组CIK细胞对靶细胞的杀伤率在相同效靶比时无明显差异(P>0.05)。RetroNectin能显著增强CIK增殖活性, 但对CIK细胞的杀伤活性并无明显影响。CIK能够显著抑制DDP-A549的生长, 可用于耐顺铂肺腺癌的免疫治疗。     

Combined Therapy with Cytokine-Induced Killer Cells and Oncolytic Adenovirus Expressing IL-12 Induce Enhanced Antitumor Activity in Liver Tumor Model

Both adoptive immunotherapy and gene therapy hold a great promise for treatment of malignancies. However, these strategies exhibit limited anti-tumor activity, when they are used alone. In this study, we explore whether combination of cytokine-induced killer (CIK) adoptive immunotherapy with oncolytic adenovirus-mediated transfer of human interleukin-12 (hIL-12) gene induce the enhanced antitumor potency. Our results showed that oncolytic adenovirus carrying hIL-12 (AdCN205-IL12) could produce high levels of hIL-12 in liver cancer cells, as compared with replication-defective adenovirus expressing hIL-12 (Ad-IL12). AdCN205-IL12 could specifically induce cytotoxocity to liver cancer cells. Combination of CIK cells with AdCN205-IL12 could induce higher antitumor activity to liver cancer cells in vitro than that induced by either CIK or AdCN205-IL12 alone, or combination of CIK and control vector AdCN205-GFP. Furthermore, treatment of the established liver tumors with the combined therapy of CIK cells and AdCN205-IL12 resulted in tumor regression and long-term survival. High level expression of hIL-12 in tumor tissues could increase traffic of CIK cells to tumor tissues and enhance their antitumor activities. Our study provides a novel strategy for the therapy of cancer by the combination of CIK adoptive immunotherapy with oncolytic adenovirus-mediated transfer of immune stimulatory molecule hIL-12.     

Effectiveness and Safety of Chemotherapy Combined with Dendritic Cells Co-Cultured with Cytokine-Induced Killer Cells in the Treatment of Advanced Non-Small-Cell Lung Cancer: A Systematic Review and Meta-Analysis

Background

Lung cancer, particularly non-small-cell lung cancer (NSCLC) is the leading cause of cancer mortality. Chemotherapy combined dendritic cells co-cultured with cytokine-induced killer cells (DC-CIK) immunotherapy has been applied in advanced NSCLC patients'' treatment, but couldn''t provide consistent beneficial results. Therefore, it is necessary to evaluate the efficiency and safety of combination therapy to promote the application.

Methods

A literature search for randomized controlled trials of NSCLC was conducted in PubMed database. Before meta-analysis was performed, studies were evaluated heterogeneity. Pooled risk ratios (RRs) were estimated and 95% confidence intervals (CIs) were calculated using a fixed-effect model. Sensitivity analysis was also performed.

Results

Six eligible trials were enrolled. Efficiency and safety of chemotherapy followed by DC-CIK immunotherapy (experimental group) and chemotherapy alone (control group) were compared. 1-year overall survival (OS) (P = 0.02) and progression free survival (PFS) (P = 0.005) in the experimental group were significantly increased compared with the control. Disease control rate (DCR) (P = 0.006) rose significantly in experimental group. However, no significant differences between the two groups were observed in 2-year OS (P = 0.21), 2-year PFS (P = 0.10), overall response rate (ORR) (P = 0.76) and partial response (PR) (P = 0.22). Temporary fever, anemia, leukopenia and nausea were the four major adverse events (AEs) treated by chemotherapy. The incidence of anemia, leukopenia and nausea in the experimental group was obviously lower than the control group. Temporary fever rate was higher in experimental group than that in the control, but could be alleviated by taking sufficient rest.

Conclusions

Chemotherapy combined with DC-CIK immunotherapy showed superiority in DCR, 1-year OS and PFS, and no more AEs appeared, however, there was no significant improvement in ORR, PR, 2-year OS and PFS. As a whole, the combination therapy is safer but modest in efficacy for advanced NSCLC patients.     

Decreased Plasma IL-35 Levels Are Related to the Left Ventricular Ejection Fraction in Coronary Artery Diseases

Background

Accumulating evidence shows that the novel anti-inflammatory cytokine IL-35 can efficiently suppress effector T cell activity and alter the progression of inflammatory and autoimmune diseases. The two subunits of IL-35, EBI3 and p35, are strongly expressed in human advanced plaque, suggesting a potential role of IL-35 in atherosclerosis and coronary artery disease (CAD). However, the plasma levels of IL-35 in patients with CAD have yet to be investigated.

Methods

Plasma IL-35, IL-10, TGF-β1, IL-12 and IL-27 levels were measured using an ELISA in 43 stable angina pectoris (SAP) patients, 62 unstable angina pectoris (UAP) patients, 56 acute myocardial infarction (AMI) patients and 47 chest pain syndrome patients as a control group.

Results

The results showed that plasma IL-35 levels were significantly decreased in the SAP group (90.74±34.22 pg/ml), the UAP group (72.20±26.63 pg/ml), and the AMI group (50.21±24.69 pg/ml) compared with chest pain syndrome group (115.06±32.27 pg/ml). Similar results were also demonstrated with IL-10 and TGF-β1. Plasma IL-12 and IL-27 levels were significantly increased in the UAP group (349.72±85.22 pg/ml, 101.75±51.42 pg/ml, respectively) and the AMI group (318.05±86.82 pg/ml, 148.88±68.45 pg/ml, respectively) compared with chest pain syndrome group (138.68±34.37 pg/ml, 63.60±22.75 pg/ml, respectively) and the SAP group (153.84±53.86 pg/ml, 70.84±38.77 pg/ml, respectively). Furthermore, lower IL-35 levels were moderately positively correlated with left ventricular ejection fraction (LVEF) in CAD patients (R = 0.416, P<0.01), whereas higher IL-27 levels were weakly negatively correlated with LVEF in CAD patients(R = −0.205, P<0.01).

Conclusions

The results of the present study show that circulating IL-35 is a potentially novel biomarker for coronary artery disease. Regulating the expression of IL-35 also provides a new possible target for the treatment of atherosclerosis and CAD.     

GMP-Compliant,Large-Scale Expanded Allogeneic Natural Killer Cells Have Potent Cytolytic Activity against Cancer Cells In Vitro and In Vivo

Ex vivo-expanded, allogeneic natural killer (NK) cells can be used for the treatment of various types of cancer. In allogeneic NK cell therapy, NK cells from healthy donors must be expanded in order to obtain a sufficient number of highly purified, activated NK cells. In the present study, we established a simplified and efficient method for the large-scale expansion and activation of NK cells from healthy donors under good manufacturing practice (GMP) conditions. After a single step of magnetic depletion of CD3⁺ T cells, the depleted peripheral blood mononuclear cells (PBMCs) were stimulated and expanded with irradiated autologous PBMCs in the presence of OKT3 and IL-2 for 14 days, resulting in a highly pure population of CD3⁻CD16⁺CD56⁺ NK cells which is desired for allogeneic purpose. Compared with freshly isolated NK cells, these expanded NK cells showed robust cytokine production and potent cytolytic activity against various cancer cell lines. Of note, expanded NK cells selectively killed cancer cells without demonstrating cytotoxicity against allogeneic non-tumor cells in coculture assays. The anti-tumor activity of expanded human NK cells was examined in SCID mice injected with human lymphoma cells. In this model, expanded NK cells efficiently controlled lymphoma progression. In conclusion, allogeneic NK cells were efficiently expanded in a GMP-compliant facility and demonstrated potent anti-tumor activity both in vitro and in vivo.     

Isolation of Sphingoid Bases of Sea Cucumber Cerebrosides and Their Cytotoxicity against Human Colon Cancer Cells

Sea cucumber is a health-beneficial food, and contains a variety of physiologically active substances including glycosphingolipids. We show here the sphingoid base composition of cerebrosides prepared from sea cucumber and the cytotoxicity against human colon cancer cell lines. The composition of sphingoid bases prepared from sea cucumber was different from that of mammals, and the major constituents estimated from mass spectra had a branched C17–19 alkyl chain with 1–3 double bonds. The viability of DLD-1, WiDr and Caco-2 cells treated with sea cucumber sphingoid bases was reduced in a dose-dependent manner and was similar to that of cells treated with sphingosine. The sphingoid bases induced such a morphological change as condensed chromatin fragments and increased the caspase-3 activity, indicating that the sphingoid bases reduced the cell viability by causing apoptosis in these cells. Sphingolipids of sea cucumber might therefore serve as bioactive dietary components to suppress colon cancer.     

Sonicated Bordetella bronchiseptica Bacterin Can Protect Dendritic Cells from Differential Cytotoxicity Caused by Doxorubicin and Vincristine and Enhance Their Antigen-Presenting Capability

Doxorubicin (DOX) and vincristine (VC) are anti-cancer drugs commonly used for lymphoma in veterinary and human medicine. However, there are several side effects caused by these drugs. In this study, the protective effects of sonicated Bordetella bronchiseptica bacterin (sBb) on dendritic cells (DCs) damaged by two anti-cancer drugs were investigated. DCs play important roles in the innate and adaptive immunity of hosts, especially activating T cells that can suppress tumor growth. The metabolic activity of DCs significantly increased after the treatment with sBb compared to that of control DCs. In addition, there was a marked change in mitochondrial integrity between DOX-treated DC and DOX + sBb-treated DCs. Flow cytometric analysis also demonstrated that sBb upregulated the expression of the surface markers of DCs, particularly CD54. In mixed lymphocyte responses, sBb significantly increased the antigen-presenting capability of DCs. In particular, sBb increased the capability of control DCs by approximately 150% and that of VC-treated DCs by 221%. These results suggest that sBb can be used as a potential immunostimulatory agent to protect DCs from anti-cancer drug-induced damage and provide fundamental information about using a combination of DCs and vincristine in immunotherapy.     

Increased Serum Levels of IL-17A and IL-23 Are Associated with Decreased Vitamin D3 and Increased Pain in Osteoarthritis

IntroductionOsteoarthritis (OA) is the most common type of arthritis and proinflammatory cytokines have been considered as the main etiologic factor in the pathogenesis of the disease. Serum levels of cytokines, that are associated with innate immunity and TH1 cells, have been analyzed in OA patients, however, there is limited research that profiles cytokines associated with Th17 cells and their relation to vitamin D3 and pain.ResultsSerum levels of IL-17A, and IL-23 were statistically higher in OA patients than in healthy controls, while IL-21 and vitamin D3 were significantly lower in OA patients when compared to controls. A significant positive correlation was found between the serum levels of IL-17A and IL-23 using WOMAC pain scores and vitamin D3 serum levels.DiscussionThe results suggest that IL-17A plays a significant role in OA pathogenesis and the induction of pain. Decreased serum levels of vitamin D3 may reflect a positive role played by the factor in the regulation of immune responses in OA patients.     

Type III Interferons,IL-28 and IL-29, Are Increased in Chronic HCV Infection and Induce Myeloid Dendritic Cell-Mediated FoxP3+ Regulatory T Cells

Background & Aims

Hepatitis C virus (HCV) is difficult to eradicate and type III interferons (IFN-λ, composed of IL-28A, IL-28B and IL-29) are novel therapeutic candidates. We hypothesized that IFN-λ have immunomodulatory effects in HCV- infected individuals.

Materials and Methods

We analyzed the expression of IFN-λ and its receptor (composed of IL-10R2 and IFN-λR subunits) in the blood and livers of patients with chronic (c)HCV infection compared to controls (those who cleared HCV by sustained virological response, SVR, and those with liver inflammation of non-viral origin, non-alcoholic steatohepatitis, NASH). We also compared the proliferative capacity of dendritic cells (DCs) obtained from healthy individuals and those with chronic HCV using a mixed leukocyte reaction combined with 3H-Td incorporation. In addition, the composition of the IFN-λ receptor (IFN-λR) on myeloid DCs, plasmacytoid DCs, PBMCs, and T cells was determined by FACS analysis.

Results

We report that the expression of IFN-λ protein in serum and mRNA in liver is increased in cHCV patients, but not in those with HCV SVR or NASH, compared to controls. Liver level of IFN-λR mirrored the expression of serum IFN-λ and was higher in cHCV, compared to controls and HCV-SVR patients, suggesting that elevation of IFN-λ and IFN-λR are HCV-dependent. We further identified that innate immune cell populations expressed complete IFN-λ receptor. In vitro, recombinant IFN-λ promoted differentiation of monocyte-derived dendritic cells (DCs) into a phenotype with low T cell stimulatory capacity and high PD-L1 expression, which further promoted expansion of existing regulatory T cells. IFN-λ-DCs failed to induce de novo generation of regulatory T cells. The inhibitory capacity of IFN-λ-DCs was counteracted by recombinant IL-12 and by neutralization of the PD-1/PD-L1 system.

Conclusions

Our novel findings of the immunomodulatory effect of IFN-λ contribute to the understanding of the anti-inflammatory and/or anti-viral potential of IFN-λ in cHCV.     

IL-4 and IL-4 Receptor Expression Is Dispensable for the Development and Function of Natural Killer T Cells

CD4 T cells acquire functional properties including cytokine production upon antigenic stimulation through the T cell receptor (TCR) and differentiate into T helper (Th) cells. Th1 cells produce interferon (IFN)-γ and Th2 cells produce interleukin (IL)-4. Th1 and 2 cells utilize IFN-γ and IL-4 for further maturation and maintenance, respectively. Promyelocytic leukemia zinc finger (PLZF)-expressing invariant natural killer T (iNKT) cells develop in the thymus and acquire functional ability to produce IL-4 and IFN-γ in the thymus in the absence of antigenic stimulation. In response to antigenic stimulation, iNKT cells rapidly produce IFN-γ and IL-4. However, it is still unknown as to whether iNKT cells require these cytokines for maturation or survival in vivo. In this study, using IL-4- and IL-4 receptor- (IL-4R) deficient mice, we demonstrate that IL-4 as well as IL-4R expression is dispensable for the development, function and maintenance of iNKT cells.     

CD86 and IL-12p70 Are Key Players for T Helper 1 Polarization and Natural Killer Cell Activation by Toll-Like Receptor-Induced Dendritic Cells

Background

Dendritic cells (DCs) determine the activation and polarization of T cells via expression of costimulatory molecules and secretion of cytokines. The function of DCs derived from monocytes ex vivo strongly depends on the composition of the maturation cocktail used.

Methodology/Principal Findings

We analyzed the effect of costimulatory molecule expression and cytokine secretion by DCs on T and natural killer (NK) cell activation by conducting a head-to-head comparison of a Toll-like receptor (TLR) agonist-based cocktail with the standard combination of proinflammatory cytokines or IL-10 alone. We could show that TLR-induced DCs are characterized by a predominance of costimulatory over coinhibitory molecules and by high secretion of IL-12p70, but not IL-10. Functionally, these signals translated into an increase in IFN-γ secreting Th1 cells and a decrease in regulatory T cells. T cell activation and polarization were dependent on IL-12p70 and CD86, but remarkably not on CD80 signaling. By means of IL-12p70 secretion, only TLR-induced DCs activated NK cells.

Conclusions/Significance

TLR-matured DCs are highly suitable for application in immunotherapeutic strategies that rely on strong type 1 polarization and NK cell activation. Their effects particularly depend on high CD86 expression and IL-12p70 secretion.     

Natural Killer Cells Mediate Protection against Yersinia pseudotuberculosis in the Mesenteric Lymph Nodes

Natural killer cells play a crucial role in the initial defense against bacterial pathogens. The crosstalk between host cells infected with intracellular pathogens and NK cells has been studied intensively, but not much attention has been given to characterize the role of NK cells in the response to extracellular bacterial pathogens such as yersiniae. In this study we used antibody-mediated NK cell depletion to address the importance of this immune cell type in controlling a Y. pseudotuberculosis infection. Analysis of the bacterial counts was used to follow the infection and flow cytometry was performed to characterize the composition and dynamic of immune cells. Depletion of NK cells led to higher bacterial loads within the mesenteric lymph nodes. We further show that in particular CD11b⁺ CD27⁺ NK cells which express higher levels of the activation marker CD69 increase within the mesenteric lymph nodes during a Y. pseudotuberculosis infection. Moreover, in response to the activation NK cells secrete higher levels of IFNy, which in turn triggers the production of the proinflammatory cytokine TNFα. These results suggest, that NK cells aid in the clearance of Y. pseudotuberculosis infections mainly by triggering the expression of proinflammatory cytokines manipulating the host immune response.     

The Use of Wavelength Modulated Raman Spectroscopy in Label-Free Identification of T Lymphocyte Subsets,Natural Killer Cells and Dendritic Cells

Determining the identity of cells of the immune system usually involves destructive fixation and chemical staining, or labeling with fluorescently labeled antibodies recognising specific cell surface markers. Completely label-free identification would be a significant advantage in conditions where untouched cells are a priority. We demonstrate here the use of Wavelength Modulated Raman Spectroscopy, to achieve label-free identification of purified, unfixed and untouched populations of major immune cell subsets isolated from healthy human donors. Using this technique we have been able to distinguish between CD4⁺ T lymphocytes, CD8⁺ T lymphocytes and CD56⁺ Natural Killer cells at specificities of up to 96%. Additionally, we have been able to distinguish between CD303⁺ plasmacytoid and CD1c⁺ myeloid dendritic cell subsets, the key initiator and regulatory cells of many immune responses. This demonstrates the ability to identify unperturbed cells of the immune system, and opens novel opportunities to analyse immunological systems and to develop fully label-free diagnostic technologies.     

Natural Killer Cells in Obesity: Impaired Function and Increased Susceptibility to the Effects of Cigarette Smoke

Background

Obese individuals who smoke have a 14 year reduction in life expectancy. Both obesity and smoking are independantly associated with increased risk of malignancy. Natural killer cells (NK) are critical mediators of anti-tumour immunity and are compromised in obese patients and smokers. We examined whether NK cell function was differentially affected by cigarette smoke in obese and lean subjects.

Methodology and Principal Findings

Clinical data and blood were collected from 40 severely obese subjects (BMI>40 kg/m²) and 20 lean healthy subjects. NK cell levels and function were assessed using flow cytometry and cytotoxicity assays. The effect of cigarette smoke on NK cell ability to kill K562 tumour cells was assessed in the presence or absence of the adipokines leptin and adiponectin. NK cell levels were significantly decreased in obese subjects compared to lean controls (7.6 vs 16.6%, p = 0.0008). NK function was also significantly compromised in obese patients (30% +/− 13% vs 42% +/−12%, p = 0.04). Cigarette smoke inhibited NK cell ability to kill tumour cell lines (p<0.0001). NK cells from obese subjects were even more susceptible to the inhibitory effects of smoke compared to lean subjects (33% vs 28%, p = 0.01). Cigarette smoke prevented NK cell activation, as well as perforin and interferon-gamma secretion upon tumour challenge. Adiponectin but not leptin partially reversed the effects of smoke on NK cell function in both obese (p = 0.002) and lean controls (p = 0.01).

Conclusions/Significance

Obese subjects have impaired NK cell activity that is more susceptible to the detrimental effects of cigarette smoke compared to lean subjects. This may play a role in the increase of cancer and infection seen in this population. Adiponectin is capable of restoring NK cell activity and may have therapeutic potential for immunity in obese subjects and smokers.     

Spontaneous Autoimmunity in the Absence of IL-2 Is Driven by Uncontrolled Dendritic Cells

BALB/c IL-2-deficient (IL-2-KO) mice develop systemic autoimmunity, dying within 3 to 5 wk from complications of autoimmune hemolytic anemia. Disease in these mice is Th1 mediated, and IFN-γ production is required for early autoimmunity. In this study, we show that dendritic cells (DCs) are required for optimal IFN-γ production by T cells in the IL-2-KO mouse. Disease is marked by DC accumulation, activation, and elevated production of Th1-inducing cytokines. IL-2-KO DCs induce heightened proliferation and cytokine production by naive T cells compared with wild-type DCs. The depletion of either conventional or plasmacytoid DCs significantly prolongs the survival of IL-2-KO mice, demonstrating that DCs contribute to the progression of autoimmunity. Elimination of Th1-inducing cytokine signals (type 1 IFN and IL-12) reduces RBC-specific Ab production and augments survival, indicating that cytokines derived from both plasmacytoid DCs and conventional DCs contribute to disease severity. DC activation likely precedes T cell activation because DCs are functionally activated even in an environment lacking overt T cell activation. These data indicate that both conventional and plasmacytoid DCs are critical regulators in the development of this systemic Ab-mediated autoimmune disease, in large part through the production of IL-12 and type 1 IFNs.     

Generation and Preclinical Characterization of an NKp80-Fc Fusion Protein for Redirected Cytolysis of Natural Killer (NK) Cells against Leukemia

The capacity of natural killer (NK) cells to mediate Fc receptor-dependent effector functions, such as antibody-dependent cellular cytotoxicity (ADCC), largely contributes to their clinical application. Given that activation-induced C-type lectin (AICL), an identified ligand for the NK-activating receptor NKp80, is frequently highly expressed on leukemia cells, the lack of therapeutic AICL-specific antibodies limits clinical application. Here we explore a strategy to reinforce NK anti-leukemia reactivity by combining targeting AICL-expressing leukemia cells with the induction of NK cell ADCC using NKp80-Fc fusion proteins. The NKp80-Fc fusion protein we generated bound specifically to leukemia cells in an AICL-specific manner. Cell binding assays between NK and leukemia cells showed that NKp80-Fc significantly increased NK target cell conjugation. In functional analyses, treatment with NKp80-Fc clearly induced the ADCC effect of NK cells. NKp80-Fc not only promoted NK-mediated leukemia cell apoptosis in the early stage of cell conjugation but also enhanced NK cell degranulation and cytotoxicity activity in the late stage. The bifunctional NKp80-Fc could redirect NK cells toward leukemia cells and triggered NK cell killing in vitro. Moreover, NKp80-Fc enhanced the lysis of NK cells against tumors in leukemia xenograft non-obese diabetic/severe combined immunodeficiency mice. Taken together, our results demonstrate that NKp80-Fc potently amplifies NK cell anti-leukemia effects in vitro and in vivo through induction of the NK cell ADCC effect. This method could potentially be useful for molecular targeted therapy, and the fusion proteins may be a promising drug for immunotherapy of leukemia.     

Killer Cell Immunoglobulin-like Receptors and Their HLA Ligands are Related with the Immunopathology of Chagas Disease

The aim of this study was to investigate the influence of killer cell immunoglobulin-like receptor (KIR) genes and their human leucocyte antigen (HLA) ligands in the susceptibility of chronic Chagas disease. This case-control study enrolled 131 serologically-diagnosed Chagas disease patients (59 men and 72 women, mean age of 60.4 ± 9.8 years) treated at the University Hospital of Londrina and the Chagas Disease Laboratory of the State University of Maringa. A control group was formed of 165 healthy individuals - spouses of patients or blood donors from the Regional Blood Bank in Maringa (84 men and 81 women, with a mean age of 59.0 ± 11.4 years). Genotyping of HLA and KIR was performed by PCR-SSOP. KIR2DS2-C1 in the absence of KIR2DL2 (KIR2DS2⁺/2DL2^-/C1⁺) was more frequent in Chagas patients (P = 0.020; Pc = 0.040; OR = 2.14) and, in particular, those who manifested chronic chagasic cardiopathy—CCC (P = 0.0002; Pc = 0.0004; OR = 6.64; 95% CI = 2.30–18.60) when compared to the control group, and when CCC group was compared to the patients without heart involvement (P = 0.010; Pc = 0.020; OR = 3.97). The combination pair KIR2DS2⁺/2DL2^-/KIR2DL3⁺/C1⁺ was also positively associated with chronic chagasic cardiopathy. KIR2DL2 and KIR2DS2 were related to immunopathogenesis in Chagas disease. The combination of KIR2DS2 activating receptor with C1 ligand, in the absence of KIR2DL2, may be related to a risk factor in the chronic Chagas disease and chronic chagasic cardiopathy.