Nanobody-based trispecific T cell engager (Nb-TriTE) enhances therapeutic efficacy by overcoming tumor-mediated immunosuppression.

BACKGROUND: T cell engagers (TCEs) have been established as an emerging modality for hematologic malignancies, but solid tumors remain refractory. However, the upregulation of programmed cell death 1 (PD-1) is correlated with T cell dysfunction that confer tumor-mediated immunosuppression. Developing a novel nanobody-based trispecific T cell engager (Nb-TriTE) would be a potential strategy to improve therapeutic efficacy. METHODS: Given the therapeutic potential of nanobodies (Nbs), we first screened Nb targeting fibroblast activation protein (FAP) and successfully generated a Nb-based bispecific T cell engager (Nb-BiTE) targeting FAP. Then, we developed a Nb-TriTE by fusing an anti-PD-1 Nb to the Nb-BiTE. The biological activity and antitumor efficacy of the Nb-TriTE were evaluated in vitro and in both cell line-derived and patient-derived xenograft mouse models. RESULTS: We had for the first time successfully selected a FAP Nb for the generation of novel Nb-BiTE and Nb-TriTE, which showed good binding ability to their targets. Nb-TriTE not only induced robust tumor antigen-specific killing, potent T cell activation and enhanced T cell function in vitro, but also suppressed tumor growth, improved survival and mediated more T cell infiltration than Nb-BiTE in mouse models of different solid tumors without toxicity. CONCLUSIONS: This novel Nb-TriTE provides a promising and universal platform to overcome tumor-mediated immunosuppression and improve patient outcomes in the future.

A dendritic/tumor fusion cell vaccine enhances efficacy of nanobody-based CAR-T cells against solid tumor.

Background: Chimeric antigen receptor (CAR) T-cell therapy is practical in treating cancers of hematopoietic origin, but of that in solid tumors compromises efficacy for the loss of the antigen recognized by the CAR. However, dendritic cell (DC)/tumor fusion vaccines present a spectrum of known or unknown tumor antigens to stimulate T cell expansion and enhanced T cell response. Developing a new strategy of enhanced nanobody-based CAR-T (Nb-CAR-T) cells antitumor activity by DC/tumor fusion vaccines stimulation would provide guidance for more effective CAR-T cell therapies. Methods: Considering the therapeutic potential of nanobody (Nb), we first screened EGFRvIII Nb, then constructed and verified the function of EGFRvIII Nb-CAR-T cells in vitro and in vivo. We further combined DC/tumor fusion vaccines to boost EGFRvIII Nb-CAR-T cells antitumor effect, which was evaluated in vitro Nb-CAR-T cell function and in the tumor-bearing xenograft mouse models. Results: We had for the first time successfully selected EGFRvIII Nb for the generation of the novel EGFRvIII Nb-CAR-T cells. Importantly, our results suggested that DC/tumor fusion vaccines stimulate Nb-CAR-T cells response not only in improving T cell proliferation, T cell activation, cytokine secretion and tumor-specific cytotoxicity in vitro, but also significantly reducing tumor burden, prolonging survival and improving Nb-CAR-T cells infiltration. Conclusions: We have innovatively shown that DC/tumor fusion vaccines significantly enhance the efficacy of Nb-CAR-T cells against solid tumors. This new strategy has provided a promising therapeutic platform for promoting the clinical treatment of CAR-T cells therapy.

Macrophages Serve as Bidirectional Regulators and Potential Therapeutic Targets for Liver Fibrosis.

Liver fibrosis is a dynamic pathological process in which the structure and function of the liver abnormally change due to long-term complex inflammatory reactions and chronic liver injury caused by multiple internal and external factors. Previous studies believed that the activation of hepatic stellate cells is a critical part of the occurrence and development of liver fibrosis. However, an increasing number of studies have indicated that the macrophage plays an important role as a central regulator in liver fibrosis, and it directly affects the development and recovery of liver fibrosis. Studies of macrophages and liver fibrosis in the recent 10 years will be reviewed in this paper. This review will not only clarify the molecular mechanism of liver fibrosis regulated by macrophages but also provide new strategies and methods for ameliorating and treating liver fibrosis.

S100A8/A9 Molecular Complexes Promote Cancer Migration and Invasion via the p38 MAPK Pathway in Nasopharyngeal Carcinoma.

Nasopharyngeal carcinoma (NPC) is one type of malignancy associated with migration and invasion through a currently unclear mechanism. We previously discovered S100A8/A9 levels were roughly elevated in the plasma of NPC patients as the promising biomarkers. However, their expressions and underlying functions in NPC tissues are still unknown. In the present study, we analyzed 49 NPC tissues and 20 chronic pharyngitis (CP) tissues. Immunohistochemical staining was performed in different tissues and analyzed by the Mann-Whitney U test statistically. Transwell migration and invasion experiments were further performed to determine S100A8/A9 effects on NPC. Our results showed that S100A8/A9 in NPC tissues were significantly higher than those in CP tissues, closely associated with NPC clinical stages. Intriguingly, exogenous S100A8/A9 protein stimulation could dramatically enhance NPC migration and invasion abilities. In addition, p38 MAPK pathway blockade could diminish the migration and invasion of NPC cells stimulated by S100A8/A9 proteins. The downstream tumor invasion and migration associated proteins (e.g., MMP7) were also elevated in NPC tissues, consistent with S100A8/A9 overexpression. Taken together, our present findings suggest that the secreted soluble inflammatory factors S100A8/A9 might promote cancer migration and invasion via the p38 MAPK signaling pathway along with invasion/migration associated proteins overexpression in the tumor microenvironment of NPC. This may shed light on the mechanism understanding of NPC prognosis and provide more novel clues for NPC diagnosis and therapy.

miRNA-34b is directly involved in the aging of macrophages.

BACKGROUND: MicroRNAs (miRNAs) are a class of short noncoding RNA that play important regulatory roles in living organisms. These RNA molecules are implicated in the development and progression of malignant diseases such as cancer and are closely associated with cell aging. Findings demonstrating that microRNA is associated with aging in macrophages have nevertheless rarely been reported. AIMS: This study's objective was to investigate if miRNA-34 is linked to aging process of macrophages. METHODS: We built a cell aging model in mouse RAW264.7 macrophages using D-galactose and determined the expression levels of miRNA-34a, miRNA-34b, and miRNA-34c in aging and normal macrophages by fluorescence quantitative polymerase chain reaction (q-PCR). We predicted a target gene of miRNA-34 using biological information techniques and constructed the recombinant plasmid pGL3-E2f3 for the putative target gene E2f3. RESULTS: The expression level of miRNA-34b was 5.23 times higher in aging macrophages than in normal macrophages. The luciferase activity decreased by nearly 50 % in cells transfected with miRNA-34b mimics, while no significant decrease in luciferase activity was noted in cells transfected with the miRNA-34b inhibitor or unrelated sequences. DISCUSSION: Our findings provide the groundwork for further research into the molecular mechanisms whereby miRNA-34b regulates the aging of macrophages. CONCLUSIONS: miRNA-34b is associated with the aging of RAW264.7 macrophages, and E2f3 is a target gene of miRNA-34b.

Radiation Changes the Metabolic Profiling of Melanoma Cell Line B16.

Radiation therapy can be an effective way to kill cancer cells using ionizing radiation, but some tumors are resistant to radiation therapy and the underlying mechanism still remains elusive. It is therefore necessary to establish an appropriate working model to study and monitor radiation-mediated cancer therapy. In response to cellular stress, the metabolome is the integrated profiling of changes in all metabolites in cells, which can be used to investigate radiation tolerance mechanisms and identify targets for cancer radiation sensibilization. In this study, using 1H nuclear magnetic resonance for untargeted metabolic profiling in radiation-tolerant mouse melanoma cell line B16, we comprehensively investigated changes in metabolites and metabolic network in B16 cells in response to radiation. Principal component analysis and partial least squares discriminant analysis indicated the difference in cellular metabolites between the untreated cells and X-ray radiated cells. In radiated cells, the content of alanine, glutamate, glycine and choline was increased, while the content of leucine, lactate, creatine and creatine phosphate was decreased. Enrichment analysis of metabolic pathway showed that the changes in metabolites were related to multiple metabolic pathways including the metabolism of glycine, arginine, taurine, glycolysis, and gluconeogenesis. Taken together, with cellular metabolome study followed by bioinformatic analysis to profile specific metabolic pathways in response to radiation, we deepened our understanding of radiation-resistant mechanisms and radiation sensibilization in cancer, which may further provide a theoretical and practical basis for personalized cancer therapy.

Folate-Modified Chitosan Nanoparticles Coated Interferon-Inducible Protein-10 Gene Enhance Cytotoxic T Lymphocytes' Responses to Hepatocellular Carcinoma.

Adoptive therapy using tumor antigen-specific cytotoxic T lymphocytes (CTLs) is a promising approach for treatment of human cancers. Due to immune suppression in cancer patients, it is difficult for tumor antigen-specific CTLs to arrive at tumor tissues. Interferon-inducible protein-10 (IP-10) is a powerful chemokine that effectively attracts CTLs to tumor tissues and improves their anti-tumor activity. Increase over expression of IP-10 in tumor tissues can efficiently promote efficacy of adoptive therapy. Folate-modified chitosan nanoparticles coating the human IP-10 gene (FA-CS-hIP-10) were therefore developed in this study. The FA-CS-hIP-10 nanoparticles were specifically bound to folate receptors on hepatoma cells and promoted the expression of IP-10, to improve the activity of pMAGE-A1(278-286) specific CTLs. Combination of the FA-CS-hIP-10 and pMAGE-A1(278-286) specific CD8+ CTLs efficiently increased secretion of IFN-γ, inhibited tumor growth and extended survival of nude mice with subcutaneously transplanted human hepatocellular carcinoma. Our results demonstrated that the mechanism behind this novel therapeutic approach involved inhibition of angiogenesis and proliferation, and also promoted apoptosis of tumor cells. Our study provides a potentially novel approach for treatment of human hepatocellular carcinoma by improving the activity of tumor antigen-specific CTLs.

Folate-modified Chitosan Nanoparticles Containing the IP-10 Gene Enhance Melanoma-specific Cytotoxic CD8(+)CD28(+) T Lymphocyte Responses.

BACKGROUND: Adoptive immunotherapy with cytotoxic T lymphocytes (CTLs) has great potential for the treatment of some malignant cancers. Therefore, augmenting the responses of tumor-specific CTLs is significant for the adoptive immunotherapy of melanoma. This study aimed to investigate the anti-tumor response of a combination therapy employing folate-modified chitosan nanoparticles containing IP-10 (interferon-γ-inducible protein-10) plus melanoma TRP2-specific CD8(+)CD28(+) T cells. METHODS: We prepared folate-modified chitosan nanoparticles containing the mouse IP-10 gene (FA-CS-mIP-10), and induced melanoma TRP2-specific CD8(+)CD28(+) T cells by co-culturing them with artificial antigen-presenting cells. B16-bearing mice were treated with FA-CS-mIP-10, melanoma TRP2-specific CD8(+)CD28(+) T cells, a combination of both, and the saline control. Tumor volumes and the survival time of mice were recorded. The proportion of myeloid-derived suppressor cells (MDSCs) infiltrating the tumor microenvironment and regulatory T cells (Tregs) in the spleen was analyzed by flow cytometry. We also detected the proliferation and angiogenesis of tumors by immunohistochemistry and apoptosis by TUNEL. RESULTS: The combination therapy inhibited the progression of melanoma in vivo. Compared with other treatments, it more efficiently inhibited tumor growth and increased the survival time of mice. After treatment with combination therapy, the proportion of MDSCs and Tregs decreased, while the percentage of CXCR3(+)CD8(+) T cells increased. Furthermore, combination therapy inhibited proliferation and promoted apoptosis of tumor cells and significantly inhibited tumor angiogenesis in vivo. CONCLUSION: We describe a novel strategy for improving the anti-tumor response of CD8(+)CD28(+) CTLs by combining them with FA-CS-mIP-10 nanoparticles.

A novel method for endothelial cell isolation.

The present study aimed to develop a quick and efficient method for purification of newborn endothelial cells from tumor tissues. Fresh tissues were separated from C57BL/6 mice bearing tumors derived from mouse lung cancer Lewis cells, fully minced and divided into two parts. One part was subjected to collagenase type I digestion with a vortex to form a single-cell suspension, while another part was digested but without a vortex. Then, the CD105+ cells were isolated using anti-CD105 antibody-coated Dynabeads. The isolated CD105+ cells were grown in culture medium and examined for the surface expression of CD105 by a fluorescence-activated cell sorter (FACS). The uptake of acetylated LDL and the ability to maintain capillary tube-like structure formation in the CD105+ cells were also examined by Dil-Ac-LDL uptake assay and tube formation assay. The expression of tumor newborn endothelial cells (CD105+) was tested in Lewis xenografts by immunohistochemistry. The number of cells which were obtained by the digestion process with a vortex was 5.70±0.23x10(4) much higher than the number without a vortex (0.32±0.04x10(4)) (P<0.01). The purity of CD105+ cell digestion with a vortex was significantly higher than that without a vortex. Dil-Ac-LDL uptake assay and tube formation assay confirmed that the CD105+ cells digested with a vortex exhibited typical functions of endothelial cells. In conclusion, the CD105+ cells isolated by the new method had high purity and displayed features of vascular endothelial cells. The modified method provides CD105+ cells with superior conditions for mechanistic research on the development of vessel-based disease.

A Smart Detection System Based on Specific Magnetic and Rolling Cycle Amplification Signal-Amplified Dual-Aptamers to Accurately Monitor Minimal Residual Diseases in Patients with T-ALL.

It is a major clinical challenge for clinicians how to early find out minimal residual diseases (MRD) of leukemia. Here, we developed a smart detection system for MRD involving magnetic aptamer sgc8 probe (M-sgc8 probe) to capture CEM cells and rolling cycle amplification probe (RCA-sgc8 probe) to initiate RCA, producing a single-stranded tandem repeated copy of the circular template. The DNA products were hybridized with molecular beacon to generate the amplified fluorescence signal. An in vitro model to mimic MRD was established to evaluate the sensitivity of the smart detection system. The smart detection system was used to detect MRD in patients with T-ALL peri-chemotherapy, which could not only specifically captured T-ALL cells, but also significantly amplified fluorescence signals on them. The sensitivity was 1/20,000. These results indicate that the smart detection system with high specificity and sensitivity could more efficiently monitor the progress of T-ALL peri-chemotherapy.

[The influence of microcystin-LR on monocytes and lymphocytes of mice].

OBJECTIVE: To investigate the influence of microcystin-LR (MC-LR) on monocytes and lymphocytes in blood of mice and to find a sensitive index of toxic effects. METHODS: Specific pathogen free Kunming male mice, aging 1 month-old,were randomly divided into 5 groups by weights, 7 mice for each group. The mice in 5 groups were exposed to MC-LR through intraperitoneal injection at 0, 3.125,6.250, 12.500 and 25.000 µg/kg respectively for 7 days. Then cytokine levels in the serum were measured by radioimmunoassay, DNA-protein crosslinks (DPC) was measured by the SDS/KCl precipitation technique, and the phagocytosis and ROS of leukocytes were detected by flow cytometry. RESULTS: The levels of interleukin 6 in the 6.250, 12.500 and 25.000 µg·kg(-1)·d(-1) dose groups were (346.837 ± 25.536), (360.847 ± 37.886) and (434.245 ± 35.858)pg/ml respectively, which were significantly higher than those in the control group which the value was (232.775 ± 32.816) pg/ml (t values were -7.258, -6.760 and -10.966 respectively, P values were all < 0.05).While the level of tumor necrosis factor-alpha was(10.782 ± 0.966) fmol/ml in 25 µg·kg(-1)·d(-1) dose group was statistically lower than it in the control group which the value was (16.878 ± 3.378) fmol/ml (t value was 4.591, P < 0.05). The DPC levels of lymphocytes in 6.250, 12.500 µg·kg(-1)·d(-1) dose group were (242.576 ± 7.545),(241.472 ± 2.793) ng/ml,higher than it in the control group while the value was (228.657 ± 4.130) ng/ml (t value was -4.282, -6.801, P values were all <0.05). The fluorescence intensity of DCF in lymphocytes in the 4 treated groups were separately 3299.37 ± 120.54, 3281.38 ± 58.34, 3308.06 ± 136.12 and 3346.92 ± 108.69, all significantly lower than 3770.81 ± 131.39 in the control group (t values were 6.995, 9.007, 6.472 and 6.577 respectively, and P values were all <0.05). The fluorescence intensity of DCF in monocytes in the 4 treated groups (3271.51 ± 140.79, 3270.05 ± 117.92, 3326.90 ± 114.39 and 3292.49 ± 145.97 respectively) were also significantly lower than the value in the control group was 3841.72 ± 130.92 (t values were 7.847, 8.584, 7.835 and 7.411 respectively, P values were all <0.05). There was no significant difference in other index among the four experiment groups and the control group. CONCLUSION: The MC-LR administered via intraperitoneal injection to mice induced the alterations of some cytokines of monocytes and lymphocytes in blood. By comparison, the ROS of leukocyte was the most sensitive index.

[The establishment and application of the method with virus concentration and detection in drinking water].

OBJECTIVE: This study aimed to construct an effective method to concentrate and detect virus in drinking water, and human adenovirus pollution status in actual water samples was monitored by constructed method. METHODS: The concentration efficient of NanoCeram filter for the first concentration with source water and drinking water and the concentration efficient of the different concentrations of PEG 8000 for the second concentration were assessed by spiking f2 bacteriophage into water samples. The standard of human adenovirus for real-time PCR was constructed by T-A clone. The plasmid obtained was identified through sequence analyzing and consistency check comparing to target gene fragment was conducted by using blast algorithm. Then, real-time PCR was constructed to quantify the concentration of human adenovirus using the plasmid as standard. Water samples were concentrated by using NanoCeram filter on the spot and then concentrated for the second time by PEG/NaCl in 2011. The DNA of concentrated samples were extracted for the quantification of human adenovirus in real-time PCR subsequently to monitor the pollution of human adenovirus in water. RESULTS: For the first concentration by NanoCeram filter, the recovery rates were (51.63 ± 26.60)% in source water and (50.27 ± 14.35)% in treated water, respectively. For the second concentration, the highest recovery rate was reached to (90.09 ± 10.50)% at the concentration of 0.13 kg/L of PEG 8000. The sequence identity score of standard of adenovirus for real time PCR and adenovirus gene was 99%, implying that it can be successfully used to quantification with human adenovirus. The levels of human adenovirus in the water samples sampled in 2011 ranged from 4.13×10³ to 2.20×106 copies/L in source water, while range from 5.57×10² to 7.52×105 copies/L in treated water and the removal efficiency range was (75.49 ± 11.71)%. CONCLUSION: NanoCeram filers combined with PEG/NaCl was an effective method to concentrate virus in aquatic environment. There was a large number of human adenovirus in source water, and it is not sufficient to remove them thoroughly through conventional water treatment processes.