Multiple antigenic polypeptide composed of heparanase B-cell epitopes shrinks human hepatocellular carcinoma in mice

Complex TNF-α B cell epitope MAP vaccine alleviates murine ulcerative colitis

The present study aimed to develop a tumor necrosis factor‑α (TNF‑α) B‑cell epitope/IL‑1β helper T lymphocyte epitope complex MAP vaccine for the alleviation of ulcerative colitis (UC) in mice. The B cell epitopes of murine TNF‑α (mTNF‑α) were predicted in silico and coupled with the universal interleukin 1β (IL‑1β) helper T‑cell epitope peptide VQGEESNDK to synthesize the eight‑branched MAP vaccine. Then, the immunological effects of the MAP vaccine were assessed in vitro and in vivo, as well as its impacts on DAI index, serum DAO levels, colon tissue tight junction protein amounts, ultrastructural changes, and MPO activity in BALB/c mice with UC. The amino acids LTLRSSSQNSSDKPV at positions 78‑92 of mTNF‑α may constitute the dominant B cell epitope. Based on this finding, an eight‑branched peptide structure, the TNF‑α B‑cell epitope/IL‑1β helper T‑cell epitope complex MAP vaccine, was synthesized. Indirect ELISA confirmed that MAP had a high affinity with commercialized mTNF‑α antibodies. Meanwhile, MAP induced high specific antibody titers in vivo, reduced the DAI score, serum MPO activity, colorectal lymph node colony count, ultrastructural injuries, colon tissue histological index score and MPO activity in UC mice, while increasing the expression levels of occludin, claudin1 and ZO1 in colon tissues. The synthetic complex MAP vaccine has good antigenicity and immunogenicity, and can alleviate UC in mouse models.

Targeting Angiogenesis With Peptide Vaccines

Most cancer peptide vaccinations tested so far are capable of eliciting a strong immune response, but demonstrate poor clinical benefits. Since peptide vaccination is safe and well-tolerated, and several indications suggest that it has clear potential advantages over other modalities of treatment, it is important to investigate the reasons for these clinical failures. In this review, the current state of the art in targeting angiogenic proteins via peptide vaccines is presented, and the underlying reasons for both the successes and the failures are analyzed. The review highlights a number of areas critical for future success, including choice of target antigens, types of peptides used, delivery methods and use of proper adjuvants, and suggests ways to achieve better clinical results in the future.

Prediction and identification of B‑cell epitopes for tumor necrosis factor‑α

The aim of the present study was to predict and identify B‑cell epitopes for mouse tumor necrosis factor‑α (mTNF‑α). DNAStar and BcePred software were used to predict B‑cell epitopes for mTNF‑α. A predicted eight‑branch multiple antigenic polypeptide (MAP) was synthesized and used to immunize BALB/c mice, combined with a promiscuous helper interleukin‑1β epitope (VQGEESNDK, amino acids 163‑171). The serum titer was measured. The specificity and avidity were determined by western blotting and indirect enzyme‑linked immunosorbent assay (ELISA). Amino acids 54‑65 (MAP1) and 78‑92 (MAP2) of mTNF‑α were predicted as most likely to be B‑cell epitopes. Dynamic monitoring of antibody concentration demonstrated that MAP1 and MAP2 may induce the production of specific antibodies with a higher antibody level for MAP2. Furthermore, MAP1 and MAP2 were confirmed to induce mTNF‑α‑specific antibodies by western blotting. Indirect ELISA was used to confirm that MAP2 had the highest affinity with commercial anti‑mTNF‑α antibody. Amino acids 54‑65 and 78‑94 of mTNF‑α are B‑cell epitopes, wherein amino acids 78‑94 have the strongest immunogenicity. The present study provides a theoretical basis for further research into the mTNF‑α polypeptide antibody and a B‑cell MAP vaccine.

Inhibition of tumor growth and metastasis by EMMPRIN multiple antigenic peptide (MAP) vaccination is mediated by immune modulation

Previously, we have identified a new epitope in EMMPRIN, a multifunctional protein that mediates tumor cell-macrophage interactions and induces both MMP-9 and VEGF. Here, we synthesized this epitope as an octa-branched multiple antigenic peptide (MAP) to vaccinate mice implanted with subcutaneous syngeneic colon (CT26), prostate (TRAMP-C2) or renal (RENCA) cell line carcinomas. Vaccination inhibited, and sometimes regressed, tumor growth in a dose-dependent manner, reaching 94%, 71% and 72% inhibition, respectively, at a 50 μg dose (p < 0.01). Mice with regressed tumors demonstrated immune memory, preventing tumor recurrence upon re-implantation (p < 0.001). When tumor cells were administered through the tail vein to generate lung metastases, vaccination reduced the number of metastatic foci (by 15- and 23-folds, p < 0.001), and increased the median survival time by 25% and 53% in RENCA and CT26 metastases, respectively (p < 0.01) relative to scrambled-MAP controls. No significant adverse responses were observed in all experiments. We show that the tumor microenvironment was immune modulated, as vaccination induced production of EMMPRIN-specific antibodies, increased CD8⁺ T cells infiltration and cytotoxicity, alleviated immune suppression by decreasing TGFβ concentrations, reduced angiogenesis and cell proliferation, and enhanced apoptosis. Thus, our successful active peptide vaccination strategy differs from previous, unsuccessful attempts, both in the selected target (the EMMPRIN epitope) and in the use of a modified, MAP configuration, and demonstrates that this may be an efficient approach for the treatment and prevention of some types of cancer.

Mechanisms of heparanase inhibitors in cancer therapy

Heparanase is an endo-β-D-glucuronidase capable of cleaving heparan sulfate side chains contributing to breakdown of the extracellular matrix. Increased expression of heparanase has been observed in numerous malignancies and is associated with a poor prognosis. It has generated significant interest as a potential antineoplastic target because of the multiple roles it plays in tumor growth and metastasis. The protumorigenic effects of heparanase are enhanced by the release of heparan sulfate side chains, with subsequent increase in bioactive fragments and cytokine levels that promote tumor invasion, angiogenesis, and metastasis. Preclinical experiments have found heparanase inhibitors to substantially reduce tumor growth and metastasis, leading to clinical trials with heparan sulfate mimetics. In this review, we examine the role of heparanase in tumor biology and its interaction with heparan surface proteoglycans, specifically syndecan-1, as well as the mechanism of action for heparanase inhibitors developed as antineoplastic therapeutics.

Heparanase: a rainbow pharmacological target associated to multiple pathologies including rare diseases

In recent years, heparanase has attracted considerable attention as a promising target for innovative pharmacological applications. Heparanase is a multifaceted protein endowed with enzymatic activity, as an endo-β-D-glucuronidase, and nonenzymatic functions. It is responsible for the cleavage of heparan sulfate side chains of proteoglycans, resulting in structural alterations of the extracellular matrix. Heparanase appears to be involved in major human diseases, from the most studied tumors to chronic inflammation, diabetic nephropathy, bone osteolysis, thrombosis and atherosclerosis, in addition to more recent investigation in various rare diseases. The present review provides an overview on heparanase, its biological role, inhibitors and possible clinical applications, covering the latest findings in these areas.