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.

Evaluating distinct KRAS subtypes as potential biomarkers for immune checkpoint inhibitor efficacy in lung adenocarcinoma.

Background: Despite the acknowledged predictive value of KRAS in immune checkpoint inhibitor (ICI) responses, the heterogeneous behavior of its mutations in this sphere remains largely unexplored. As of now, no studies have definitively categorized KRAS subtype variations as independent prognostic indicators for ICI responses in lung cancer patients. Methods: We analyzed a cohort of 103 patients, all harboring different KRAS mutation subtypes, and complemented this data with information from TCGA and GEO databases. Our research focused on delineating the relationships between KRAS mutation subtypes and factors like immunotherapy markers and immune cell composition, in addition to examining survival rates, drug sensitivity, and PD-L1 responses corresponding to distinct KRAS subtypes. Results: We found that the G12V and G12D subtypes demonstrated elevated expressions of immunotherapy markers, implying a potentially enhanced benefit from immunotherapy. Significant variations were identified in the distribution of naive B cells, activated CD4+ memory T cells, and regulatory T cells (Tregs) across different KRAS mutant subtypes. A notable difference was observed in the Tumor Mutation Burden (TMB) levels across the four KRAS subtypes, with the G12D subtype displaying the lowest TMB level. Furthermore, G12C subtype showcased the worst prognosis in terms of progression-free intervals (PFI), in stark contrast to the more favorable outcomes associated with the G12A subtype. Conclusion: Our study reveals that KRAS mutations exhibit considerable variability in predicting outcomes for LUAD patients undergoing ICI treatment. Thus, the evaluation of KRAS as a biomarker for ICIs necessitates recognizing the potential diversity inherent in KRAS mutations.

Single-Cell Profiling of Tumor-Associated Neutrophils in Advanced Non-Small Cell Lung Cancer.

Purpose: Neutrophils act as a non-negligible regulator in the initiation and progression of malignancies, playing bifacial roles in the process. Thus, to understand the heterogeneity of tumor-associated neutrophils (TANs) comprehensively in advanced non-small cell lung cancer (NSCLC) at single-cell resolution is necessary and urgent. Materials and Methods: We applied single-cell RNA-sequencing (scRNA-seq) to portray the subtype-specific transcriptome landscape of TANs in advanced NSCLC using nine freshly obtained specimens. The scRNA-seq data were further processed for pseudo-time analysis to depict the developmental trajectory of TANs. Meanwhile, the interplay between TANs and other cell types within tumor microenvironment (TME) was revealed by intercellular interaction analysis. Results: Seven distinct TAN subtypes were defined, of which, the N3 cluster was considered inflammatory phenotype expressing genes encoding multiple chemotactic cytokines, and correlated with inferior overall survival, indicating that N3 might be a pro-tumorigenic TAN subtype. N1 and N5 clusters were considered to be well differentiated and mature neutrophils based on CXCR2 expression and pseudo-time patterns, and both accounted for relatively high proportions in lung adenocarcinoma. In addition, genes related to neutrophil differentiation were discovered. We also found that TAN subtypes interacted most closely with macrophages through chemokine signaling pathways within TME. Conclusion: Our study refined TAN subtypes and mapped the transcriptome landscape of TANs at single-cell resolution in advanced NSCLC, collectively indicating the heterogeneity of TANs in NSCLC. Neutrophil differentiation- and maturation-related genes were also discovered, which shed light on different functions of TAN subclones in tumor immune escape, and may further provide novel targets for immunotherapy.

Efficacy of immune checkpoint inhibitors in advanced non-small cell lung cancer harboring BRAF mutations.

Background: Despite immune checkpoint inhibitors (ICI) being widely used to treat patients with advanced non-small cell lung cancer (NSCLC), few studies examine the role of ICI in patients with proto-oncogene B-Raf, serine/threonine kinase (BRAF) mutations. Methods: A retrospective study was conducted for patients with BRAF-mutant NSCLC who received treatment at Shanghai Pulmonary Hospital between 2014 and 2022. Primary end point was progression-free survival (PFS). Secondary end point was best response (RECIST, version 1.1). Results: The study involved a total of 34 patients with 54 treatments recorded. The median PFS for the whole cohort was 5.8 months and the overall objective response rate (ORR) was 24%. Patients who were treated with ICI combined with chemotherapy reported a median PFS of 12.6 months and an ORR of 44%. Those who were treated with non-ICI therapy came with a median PFS of 5.3 months and an ORR of 14%. Specifically, patients had better clinical benefits with first-line ICI-combined therapy. The PFS was 18.5 months whereas that of non-ICI group was 4.1 months. The ORR was 56% in ICI-combined group and 10% in non-ICI cohort. Conclusions: The findings observed an evidential and significant susceptibility to ICIs combined therapy in patients with BRAF-mutant NSCLC, especially in first-line treatment.

Computational recognition of LncRNA signatures in tumor-associated neutrophils could have implications for immunotherapy and prognostic outcome of non-small cell lung cancer.

Cancer immune function and tumor microenvironment are governed by long noncoding RNAs (lncRNAs). Nevertheless, it has yet to be established whether lncRNAs play a role in tumor-associated neutrophils (TANs). Here, a computing framework based on machine learning was used to identify neutrophil-specific lncRNA with prognostic significance in squamous cell carcinoma and lung adenocarcinoma using univariate Cox regression to comprehensively analyze immune, lncRNA, and clinical characteristics. The risk score was determined using LASSO Cox regression analysis. Meanwhile, we named this risk score as "TANlncSig." TANlncSig was able to distinguish between better and worse survival outcomes in various patient datasets independently of other clinical variables. Functional assessment of TANlncSig showed it is a marker of myeloid cell infiltration into tumor infiltration and myeloid cells directly or indirectly inhibit the anti-tumor immune response by secreting cytokines, expressing immunosuppressive receptors, and altering metabolic processes. Our findings highlighted the value of TANlncSig in TME as a marker of immune cell infiltration and showed the values of lncRNAs as indicators of immunotherapy.

Shuangxinfang Prevents S100A9-Induced Macrophage/Microglial Inflammation to Improve Cardiac Function and Depression-Like Behavior in Rats After Acute Myocardial Infarction.

Background: Depression is a common complication of cardiovascular disease, which deteriorates cardiac function. Shuangxinfang (psycho-cardiology formula, PCF) was reported to alleviate myocardial ischemia injury and improve depression-like behavior. Interestingly, our previous proteomics study predicted that the protein S100A9 appeared as an important target, and macrophage/microglial inflammation might be involved in the process of PCF improving depression induced by acute myocardial infarction (AMI). This study aims to validate the proteomics results. Methods: AMI rat models were established in vivo, followed by the administration of PCF or ABR-215757 (also named paquinimod, inhibiting S100A9 binding to TLR4) for 5 days. Forced swimming test (FST) and open field test (OFT) were applied to record depression-like behavior, and echocardiography was employed to evaluate cardiac function. Morphological changes of cardiomyocytes were assessed by HE staining and TUNEL staining on day 7 after cardiac surgery, as well as Masson trichrome staining on day 21. Hippocampal neurogenesis was determined by Nissl staining, while 5-hydroxytryptamine (5-HT), tryptophan/kynurenine ratio, and brain-derived neurotrophic factor (BDNF) in the hippocampus were analyzed as biochemical indicators of depression. We employed RT-qPCR, western blotting, and immunofluorescence to detect the expression of pathway-related genes and proteins. Myocardial and hippocampal expression of inflammatory factors were performed by ELISA. The activation of macrophage and microglia was assessed via immunoreaction using CD68 and Iba1, respectively. For in vitro confirmation, BV2 cells were primed with recombinant protein S100A9 and then treated with PCF serum or ferulic acid to determine alterations in microglial inflammation. Results: Rats in the AMI group showed heart function deterioration and depression-like behavior. Coronary ligation not only brought about myocardial inflammation, cell apoptosis, and fibrosis but also reduced the neurogenesis, elevated the tryptophan/kynurenine ratio, and decreased the content of 5-HT. PCF could ameliorate the pathological and phenotypic changes in the heart and brain and inhibit the expression of the S100A9 protein, the activation of the microglial cell, and the secretion of IL-1ß and TNF-α raised by AMI. ABR-215757 showed therapeutic effect and molecular biological mechanisms similar to PCF. Treatment with PCF serum or ferulic acid in vitro was proved to efficiently block the hyperactivation of BV2 cells and increment of cytokine contents induced by recombinant protein S100A9. Conclusion: We identify S100A9 as a novel and potent regulator of inflammation in both the heart and brain. Macrophage/microglia inflammation mediated by S100A9 is considered a pivotal pathogenic in depression after AMI and a major pathway for the treatment of PCF, suggesting that PCF is a promising therapeutic candidate for psycho-cardiology disease.

Psycho-cardiology therapeutic effects of Shuangxinfang in rats with depression-behavior post acute myocardial infarction: Focus on protein S100A9 from proteomics.

BACKGROUND: Depressive disorders induced by acute myocardial infarction (AMI) play a pivotal role in the deterioration of cardiac function, and Shuangxinfang (Psycho-cardiology Formula, PCF) was reported to alleviate heart function damage and improve depression-like behavior, but the complex mechanism in such process has not been clarified. METHODS: AMI models were established and PCF was administered in rats. Subjects were then assessed in open field test (OFT) and forced swimming test (FST) recapitulating symptoms of depressive disorder. Afterward, pharmacoproteomic profiling of the hippocampus and peri-infarct border zone (BZ) was performed using a label-free liquid chromatography-tandem mass spectrometry (LC-MS/MS) technique, to identify contributing proteins and pathways responsible for myocardial ischemia and behavioral allostasis. Bioinformatics analysis was processed for further investigation, while western blotting was employed for testing dominating proteins to validate proteomic results. RESULTS: Rats in the AMI group showed depression-like behavior in OFT and FST, which was improved by PCF. There were 131 differentially expressed proteins (DEPs) in BZ and 64 proteins in the hippocampus being detected and quantified shared by the sham group, the AMI group, and the PCF group. Subsequently, pertinent pathways and molecular functions were further identified. Altered molecules were discovered to be enriched in the apoptotic process, innate immune response, and NF-κB transcription factor activity in BZ, as well as chemical synaptic transmission, axon, collagen binding, cell adhesion, response to carbohydrate, laminin binding, and cellular response to nitric oxide in the hippocampus. Groups of signal transducers were also able to select multiple pathways, including innate immunity and arginine biosynthesis in the heart, also integrin signaling in the brain. DEPs were intersected from the myocardium and hippocampus to screen out the protein S100A9, which was up-regulated in the AMI group compared with the sham, and showed a down-regulation trend after treatment with PCF. CONCLUSION: Taken together, we present a comprehensive proteomics analysis of rat models with depression post-AMI. Reviewing the literatures concerned, it's hypothesized that macrophage/microglia inflammation mediated by S100A9 might be the pivotal pathogenic process of psycho-cardiology disease, as well as potential mechanisms for the treatment of PCF.

Nanobody-based chimeric antigen receptor T cells designed by CRISPR/Cas9 technology for solid tumor immunotherapy.

Chimeric antigen receptor-based T-cell immunotherapy is a promising strategy for treatment of hematological malignant tumors; however, its efficacy towards solid cancer remains challenging. We therefore focused on developing nanobody-based CAR-T cells that treat the solid tumor. CD105 expression is upregulated on neoangiogenic endothelial and cancer cells. CD105 has been developed as a drug target. Here we show the generation of a CD105-specific nanobody, an anti-human CD105 CAR-T cells, by inserting the sequences for anti-CD105 nanobody-linked standard cassette genes into AAVS1 site using CRISPR/Cas9 technology. Co-culture with CD105+ target cells led to the activation of anti-CD105 CAR-T cells that displayed the typically activated cytotoxic T-cell characters, ability to proliferate, the production of pro-inflammatory cytokines, and the specific killing efficacy against CD105+ target cells in vitro. The in vivo treatment with anti-CD105 CAR-T cells significantly inhibited the growth of implanted CD105+ tumors, reduced tumor weight, and prolonged the survival time of tumor-bearing NOD/SCID mice. Nanobody-based CAR-T cells can therefore function as an antitumor agent in human tumor xenograft models. Our findings determined that the strategy of nanobody-based CAR-T cells engineered by CRISPR/Cas9 system has a certain potential to treat solid tumor through targeting CD105 antigen.

Effect and safety of Chinese patent medicine capsules for recurrent angina pectoris after percutaneous coronary intervention: A protocol for systematic review and meta-analysis.

INTRODUCTION: Recurrent angina pectoris after percutaneous coronary intervention (PCI) is a common clinical syndrome, which seriously reduces the quality of life and health of patients, increases medical costs, and causes the risk of cardiogenic death. The efficacy of various western medicine improving angina symptoms has not been fully confirmed at the moment, whereas Chinese patent medicine capsules (CPMC) have been generally used in clinical practice due to the therapeutic efficacy and safety. This study evaluates the efficacy and safety of CPMC for stable angina after PCI, designed to provide more evidence for clinical treatment. METHODS: This protocol was based on the previous reporting items. We will search 3 English databases (PubMed, Excerpta Medica Database, and the Cochrane Library) and 3 Chinese databases (China Network Knowledge Infrastructure, Wan Fang Database, and Chinese Biomedicine) until January 2020. RCTs to evaluate the efficacy and safety of CPMC for recurrent stable angina pectoris after PCI will be included. The primary outcome will be assessed by major adverse cardiovascular events and angina attack frequency. We will use the criteria provided by Cochrane risk of bias tool for quality evaluation and risk assessment, and use the Revman 5.3 for meta-analysis. ETHICS AND DISSEMINATION: Ethical approval is not required for systematic review and meta-analysis. The results of this review will be disseminated in a peer-review journal. PROSPERO REGISTRATION NUMBER: CRD42020164005.

Efficacy and safety of the traditional Chinese medicine tonifying kidney (bu shen) therapy in patients with hypertension: A protocol for systematic review and meta-analysis.

BACKGROUND: Hypertension becomes increasingly an alarming global health concern. There is a growing interest in treatment of traditional Chinese medicine (TCM), and tonifying kidney therapy (bushen, TKT) has been extensively used in the treatment of hypertension according to TCM theory. In this article, we outline the protocol of research projects and methods to examine comprehensively the effectiveness and safety of TKT in treating hypertensive patients. METHODS: We will collect randomized controlled trails (RCTs) that report the application of TKT for patients with hypertension from electronic databases including PubMed, EMBASE, CENTRAL, CNKI, VIP, CBM, and Wanfang database. Time of literature retrieval is set from the beginning of database construction to the end of June, 2020. Two reviewers will independently perform literature screening, data extraction, and quality assessment of included literature, and any divergences will be worked out via discussion. The primary outcomes include total efficacy rate, systolic and diastolic blood pressure change will be assessed. The secondary outcomes include clinical symptoms and adverse events will also be assessed. RevMan5.3 software will be applied to analyzing data included studies. RESULTS: This study will synthesize and analyze all collated data in order to evaluate TKT for the treatment of hypertension involves different aspects in total efficacy rate, systolic and diastolic blood pressure change, clinical symptoms, and adverse events. CONCLUSION: This study will determine the efficacy of TKT in the treatment of hypertension and recommend its clinical value based on the evaluated the effectiveness and security results. REGISTRATION NUMBER: INPLASY202050044.

A Nanobody Against Cytotoxic T-Lymphocyte Associated Antigen-4 Increases the Anti-Tumor Effects of Specific CD8+ T Cells.

Adoptive cell-based immunotherapy typically utilizes cytotoxic T lymphocytes (CTLs), expanding these cells ex vivo. Such expansion is traditionally accomplished through the use of autologous APCs that are capable of interactions with T cells. However, incidental inhibitory program such as CTLA-4 pathway can impair T cell proliferation. We therefore designed a nanobody which is specific for CTLA-4 (CTLA-4 Nb 16), and we then used this molecule to assess its ability to disrupt CTLA-4 signaling and thereby overcome negative costimulation of T cells. With CTLA-4 Nb16 stimulation, dendritic cell/hepatocellular carcinoma fusion cells (DC/HepG2-FCs) enhanced autologous CD8+ T cell proliferation and production of IFN-γ in vitro, thereby leading to enhanced killing of tumor cells. Using this approach in the context of adoptive CD8+ immunotherapy led to a marked suppression of tumor growth in murine NOD/SCID hepatocarcinoma or breast cancer xenograft models. We also observed significantly increased tumor cell apoptosis, and corresponding increases in murine survival. These findings thus demonstrate that in response to nanobody stimulation, DC/tumor cells-FC-induced specific CTLs exhibit superior anti-tumor efficacy, making this a potentially valuable means of achieving better adoptive immunotherapy outcomes in cancer patients.

Opportunities and Challenges for Antibodies against Intracellular Antigens.

Therapeutic antibodies are one most significant advances in immunotherapy, the development of antibodies against disease-associated MHC-peptide complexes led to the introduction of TCR-like antibodies. TCR-like antibodies combine the recognition of intracellular proteins with the therapeutic potency and versatility of monoclonal antibodies (mAb), offering an unparalleled opportunity to expand the repertoire of therapeutic antibodies available to treat diseases like cancer. This review details the current state of TCR-like antibodies and describes their production, mechanisms as well as their applications. In addition, it presents an insight on the challenges that they must overcome in order to become commercially and clinically validated.

Enhanced cytotoxic T lymphocytes recruitment targeting tumor vasculatures by endoglin aptamer and IP-10 plasmid presenting liposome-based nanocarriers.

Background: Adequate recruitment of highly active tumor antigen-specific cytotoxic T lymphocytes (CTLs) remains a major challenge in cancer immunotherapy. Objective: To construct liposome (LP)-based nanocapsules with surface endoglin aptamer (ENG-Apt) encapsulating mouse interferon-inducible protein-10 (mIP-10), with the ability to target mouse tumor vascular endothelial cells (mTECs) and enhance CTLs targeting and recruitment to the tumor vasculature. Methods: ENG-Apt/mIP-10-LP nanocapsules were prepared by grafting DSPE-PEG2000-ENG-Apt on the surface of liposomes containing mIP-10 plasmids, characterized and assessed for the cell binding specificity in vitro. The tumor-targeting ability of ENG-Apt/mIP-10-LP nanocapsules was evaluated in vivo. The anti-tumor efficacy of ENG-Apt/mIP-10-LP nanocapsules treatment, as well as the combination treatment of ENG-Apt/mIP-10-LP nanocapsules and adoptive TRP2CD8+ T cells, were both tested in melanoma-bearing mice, by evaluation of the tumor volume and the mouse survival time. To discuss the anti-tumoral mechanism of ENG-Apt/mIP-10-LP nanocapsules-based therapies, IFN-γ secretion, proportion of TRP2CD8+ T cells among TILs, MDSCs in the tumor microenvironment and Tregs in the spleen, were determined after the treatments. Proliferation and apoptosis of tumor cells, and tumor angiogenesis were also assessed. Results: The prepared ENG-Apt/mIP-10-LP nanocapsules possess an adequate nanometric size, good stability, high specificity to mTECs and tumor sites, along with the ability to induce mIP-10 expression in vitro and in vivo. Treatment of ENG-Apt/mIP-10-LP nanocapsules demonstrated CTLs enrichment into the tumor site, which inhibited tumor cell proliferation and angiogenesis, as well as promoted tumor-cell apoptosis, leading to a decrease in tumor progression and prolonged survival time in melanoma tumor-bearing mice. In addition, the proportion of MDSCs and Tregs was found to decrease. The combination of ENG-Apt/mIP-10-LP nanocapsules with adoptive TRP2CD8+ T cells, showed stronger abilities in inhibiting tumor growth and increasing animal survival time, thereby displayed an enhanced anti-melanoma tumor efficacy, due to the recruitment of both endogenous CD8+ T cells and exogenous TRP2CD8+ T cells in vivo. Conclusion: ENG-Apt/mIP-10-LP nanocapsules could enhance the recruitment of both endogenous and exogenous CTLs specifically targeting melanoma tumor vasculatures and exert anti-tumoral effect, therefore provides a potentially novel strategy for tumor immunotherapy.

Highly sensitive detection of CTLA-4-positive T-cell subgroups based on nanobody and fluorescent carbon quantum dots.

The detection of cytotoxic T-lymphocyte antigen-4-positive (CTLA-4+) T-cell subgroups in peripheral blood samples and tumor tissues is of great significance. In the present study, a rapid, succinct and efficient method was designed for the detection of CTLA-4+ human T cells using a CTLA-4-specific nanobody-fluorescent carbon quantum dots complex (QDs-Nb36). QDs-Nb36 was used for high sensitivity detection of CTLA-4+ T cells by flow cytometry or immumofluorescent staining. The present study demonstrated that the novel technique was more specific and effective in the detection of CTLA-4+ T-cell ratio in the peripheral blood and tumor tissues compared with a traditional monoclonal antibody approach. Furthermore, no significant toxicity was identified in vitro and in vivo, thus suggesting that the method may have broad applications for the detection of certain lowly expressed targets.

Carotid plaque magnetic resonance imaging and recurrent stroke risk: A protocol for systematic review and meta-analysis.

BACKGROUND & AIMS: Carotid atherosclerotic plaque is an important cause of carotid artery stenosis. The features of carotid atherosclerotic plaque detected by relevant magnetic resonance imaging (MRI), such as lipid core, plaque hemorrhage, and fibrous cap rupture, have been confirmed to be associated with the occurrence of the first cerebral ischemic event. Meanwhile, the features of carotid atherosclerotic plaque can be used as biomarkers to predict the occurrence of cerebral ischemic event. However, the mechanism of recurrent stroke is still unclear. A systematic review and meta-analysis will be performed to summarize the association between features of carotid artery plaque detected by MRI and recurrent stroke, so as to find biomarkers that can predict recurrent stroke. METHODS: Electronic search will be performed in PUBMED, EMBASE, Cochrane Controlled Register of Trials (CENTRAL) from inception to October 30, 2018. We will include cohort studies with an average follow-up time of >1 month in which lipid-rich/necrotic cores (LRNC), intraplaque hemorrhage (IPH), and thinned or ruptured fibrous caps (TRFC) are associated with recurrent ipsilateral stroke or ischemic events. We will perform heterogeneity assessment before carrying out meta-analysis. According to the heterogeneity, we select random effect model or fixed effect model for meta-analysis of the included cohort studies. RESULTS: Review Manager 5.3 software will be used to calculate the combined hazard ratio value and 95% confidence interval (CI). This meta-analysis will provide high-quality data analysis of LRNC, IPH, and TRFC and ipsilateral recurrent stroke or ischemic events, including biomarkers as major predictors. CONCLUSION: The systematic review will provide evidence to assess the association between features of carotid plaque and ipsilateral recurrent stroke or ischemic events. PROSPERO REGISTRATION NUMBER: PROSPERO CRD42019124043.

Anti-Tumor Activity of Mannose-CpG-Oligodeoxynucleotides-Conjugated and Hepatoma Lysate-Loaded Nanoliposomes for Targeting Dendritic Cells In Vivo.

Dendritic cell (DC)-based tumor vaccines are a promising immunotherapeutic method of cancer treatment. However, their therapeutic applications are significantly limited by their weak immunogenicity, costly culturing steps, and easily degradable properties. Thus, the anti-tumor activity for the vaccines should be improved. In this study, a novel lipid nanoparticle (M/CpG-ODN-H22-Lipo) was developed, which was conjugated with synthetic CpG oligodeoxynucleotides (CpG-ODN) and mannose and then loaded with H22 hepatoma lysate. Our data corroborate that M/CpG-ODN-H22-Lipo selectively targeted DCs and significantly increased their induced-maturation. Besides, the vaccine halted tumor growth and extended survival of mice with hepatocellular carcinoma. Moreover, M/CpG-ODN-H22-Lipo treatment reduced the percentages of myeloid-derived suppressor cells (in the tumor and bone marrow) and regulatory T cells (Treg) in the spleen. In contrast, the number of IFN-gamma-positive cells in the spleen along with the serum IgG levels were up-regulated. Moreover, tumor angiogenesis and tumor-cell proliferation were halted by the treatment of M/CpG-ODN-H22-Lipo, whereas tumor cell apoptosis was up-regulated. Our data revealed that CD8 + T cells and NK cells were vital to mediate the anti-tumor immunity of M/CpG-ODN-H22-Lipo treatment. In sum, the results here proved M/CpG-ODN-H22-Lipo vaccine a safe, specific and effective DC-based anti-tumor immunotherapy with great potential for clinical applications.

Fusion of Dendritic Cells and Cancer-Associated Fibroblasts for Activation of Anti-Tumor Cytotoxic T Lymphocytes.

Here we explored the fusion of dendritic cells (DCs), potent antigen-presenting cells that initiate primary immune responses, with cancer-associated fibroblasts (CAFs), which are a stromal component needed for tumor progression, with the aim of stimulating T cells to inhibit tumor growth. Dendritic cells from the bone marrow of BALB/c mice were co-cultured with CAFs from H22 mouse hepatoma cells. CAFs were found to express fibroblast activation protein and α-smooth muscle actin by flow cytometry, Western blotting and immunofluorescence. Polyethylene glycol was added to the co-culture medium to encourage fusion, and the ability of the resulting fusion cells to produce TNF-α, IL-1ß, IL-6, and IL-12p70 was confirmed using ELISA. These fusion cells efficiently stimulated T lymphocytes in vitro, causing them to generate IFN-α and IFN-γ. T cells activated by DC/CAF fusion cells led to strong CTL response against CAFs in vitro. The activated T cells also inhibited growth of H22 xenografts in vivo. These results indicate that DC/CAF fusion cells show potential for stimulating T cells as a novel anti-tumor vaccine.

The enhanced antitumor-specific immune response with mannose- and CpG-ODN-coated liposomes delivering TRP2 peptide.

PURPOSE: Dendritic cell (DC)-based cancer vaccines is a newly emerging and potent form of immune therapy. As for any new technology, there are still considerable challenges that need to be addressed. Here, we investigate the antitumor potential of a novel liposomal vaccine, M/CpG-ODN-TRP2-Lipo. METHODS: We developed a vaccination strategy by assembling the DC-targeting mannose and immune adjuvant CpG-ODN on the surface of liposomes, which were loaded with melanoma-specific TRP2180-188 peptide as liposomal vaccine. M/CpG-ODN-TRP2-Lipo treatment was used to intendedly induce activation of DCs and antitumor- specific immune response in vivo. RESULTS: Our results demonstrated in vitro that the prepared liposomal particles were efficiently taken up by DCs. This uptake led to an enhanced activation of DCs, as measured by the upregulation of MHC II, CD80, and CD86. Furthermore, M/CpG-ODN-TRP2-Lipo effectively inhibited the growth of implanted B16 melanoma and prolonged the survival of mice. This therapy significantly reduced the number of myeloid-derived suppressor cells (MDSCs) and regulatory T cells, while simultaneously increasing the number of activated T cells, tumor antigen-specific CD8+ cytotoxic T cells, and interferon-γ-producing cells. At the same time, it was found to suppress tumor angiogenesis and tumor cell proliferation, as well as up-regulate their apoptosis. Interestingly, MyD88-knockout mice had significantly shorter median survival times compared to wild-type mice following the administration of M/CpG-ODN-TRP2-Lipo. CONCLUSIONS: The results suggested that the antitumor activities of the vaccine partially rely on the Myd88 signaling pathway. Interestingly, compared to whole tumor cell lysate-based vaccine, M/CpG-ODN-TRP2-Lipo, tumor specific antigen peptide-based vaccine, improved survival of tumor-bearing mice as well as enhanced their antitumor responses. All in all, we describe a novel vaccine formulation, M/CpG-ODN-TRP2-Lipo, with the aim of improving antitumor responses by alleviating the immunosuppressive environment in tumors.

Natural Single-Domain Antibody-Nanobody: A Novel Concept in the Antibody Field.

Since the serendipitous discovery of heavy-chain antibodies in Camelidae 20 years ago, the smallest single-domain antigen-binding fragment, known as VHH or nanobody, has received growing attention. In comparison with traditional antibodies, VHHs performs equally high specificity and affinity and low toxicity to targets, and has the ability to inhibit the formation of enzymes and enter the receptor gap. Hence, VHHs has been recently regarded as the highly valued protein and applied in multiple fields, including fundamental research, diagnosis, therapeutics, food science, etc. Today, based on the past achievements, an increasing number of academic and industrial groups begin to explore innovative VHH applications. In this review, we make a thorough retrospect of the unique features and explore novel implementations of VHHs in diverse forms in different fields. In addition, we also propose the potential future issues and problems of VHHs in many fields.