Fully Synthetic Invariant NKT Cell-Dependent Self-Adjuvanting Antitumor Vaccines Eliciting Potent Immune Response in Mice.

Constructing an effective therapeutic cancer vaccine is very attractive and promising for cancer immunotherapy. However, the poor immunogenicity of tumor antigens and suppression of the immune system in the tumor microenvironment are two major obstacles for developing effective cancer vaccines. Invariant NKT cells (iNKT cells), which are essential bridges between the innate and adaptive immune systems, can be rapidly activated by their agonists and, consequently, evoke whole immune systems. Herein, we conjugated a potent agonist of the iNKT cell, α-galactosylceramide (α-GalCer), with the tumor-associated MUC1 glycopeptide antigens as novel self-adjuvanting cancer vaccines through click chemistry. Immunological studies revealed that the mouse immune system was potently evoked and that high levels of tumor-specific IgG antibodies were elicited by vaccine conjugates without an external adjuvant. The produced antibodies could specifically recognize and bind to antigen-expressing cancer cells and, subsequently, induce cytotoxicity through complement-dependent cytotoxicity. Thus, the insertion of α-GalCer significantly improved the immunogenicity of the MUC1 glycopeptide and induced strong antigen-specific antitumor responses, indicating that α-GalCer is an effective built-in adjuvant for constructing potent chemical synthetic antitumor vaccines.

Self-Assembled Nano-Immunostimulant for Synergistic Immune Activation.

Immunotherapy has become one of the most promising therapies for the treatment of diseases. Synthetic immunostimulants and nanomaterial immunostimulant systems are indispensable for the activation of the immune system in cancer immunotherapy. Herein, a strategy for preparing self-assembled nano-immunostimulants (SANIs) for synergistic immune activation is reported. Three immunostimulants self-assemble into nanoparticles through electrostatic interactions. SANIs showed strong synergistic immunostimulation in macrophages. SANIs could also induce a strong antitumor immune response to inhibit tumor growth in mice and act as an efficient adjuvant of antitumor vaccines. Therefore, SANIs may be generally applied in cancer immunotherapy. This novel SANI strategy provides a new way for the development of both immunostimulants and -suppressants.

Synthetic MUC1 Antitumor Vaccine Candidates with Varied Glycosylation Pattern Bearing R/S-configured Pam3 CysSerLys4.

The Toll-like receptor 2 ligand Pam3 CysSer is of particular interest for the construction synthetic vaccines because of its ability to stimulate of the innate immune system. Such vaccines usually comprise Pam3 CysSer with the natural R-configuration at the glycerol 2-position. Pam3 CysSer peptide vaccines with natural configuration have been shown to be more efficient than the corresponding R/S diastereomers. In order to clarify whether the effect of the configuration of Pam3 Cys on the immune response also applies to glycopeptide vaccines, MUC1 glycopeptide-lipopeptide vaccines bearing either R- or R/S-configured Pam3 CysSerLys4 were compared for their immunological effects. In order to find out whether glycosylated MUC1 tandem repeat domains comprise not only B-cell epitopes but also T-cell epitopes, two-component vaccines containing the Pam3 CysSerLys4 lipopeptide and MUC1 glycopeptides with various glycosylation patterns were synthesized, and their immune reactions in mice were studied.

Glycopeptide Nanoconjugates Based on Multilayer Self-Assembly as an Antitumor Vaccine.

Antitumor vaccine, which is promising for tumor therapy, has been extensively studied. Some encouraging results of chemically synthetic vaccine designs based on the tumor-associated antigen mucin 1 have been achieved. However, some shortcomings such as low efficiency and difficult purification restrict their clinical application. To overcome these difficulties, we designed a novel antitumor vaccine of glycopeptide nanoconjugates based on the multilayer self-assembly through the interaction of positive and negative charges. This vaccine formed the spherical structure and effectively activated the macrophage in vitro. Besides, it also induced high titer of antibodies against mucin 1 glycopeptide. The induced antibodies could highly bind to the tumor cells and effectively kill them by activation of the complement dependent cytotoxicity complex. This novel strategy provides a new way for the development of simple and effective antitumor vaccine.

Covalent bond or noncovalent bond: a supramolecular strategy for the construction of chemically synthesized vaccines.

A novel noncovalent strategy to construct chemically synthesized vaccines has been designed to trigger a robust immune response and to dramatically improve the efficiency of vaccine preparation. Glycosylated MUC1 tripartite vaccines were constructed through host-guest interactions with cucurbit[8]uril. These vaccines elicited high levels of IgG antibodies that were recognized by transformed cells and induced the secretion of cytokines. The antisera also mediated complement-dependent cytotoxicity. This noncovalent strategy with good suitability, scalability, and feasibility can be applied as a universal strategy for the construction of chemically synthesized vaccines.

Synthetic multivalent glycopeptide-lipopeptide antitumor vaccines: impact of the cluster effect on the killing of tumor cells.

Multivalent synthetic vaccines were obtained by solid-phase synthesis of tumor-associated MUC1 glycopeptide antigens and their coupling to a Pam3 Cys lipopeptide through click reactions. These vaccines elicited immune responses in mice without the use of any external adjuvant. The vaccine containing four copies of a MUC1 sialyl-TN antigen showed a significant cluster effect. It induced in mice prevailing IgG2a antibodies, which bind to MCF-7 breast tumor cells and initiate the killing of these tumor cells by activation of the complement-dependent cytotoxicity complex.

Fully synthetic self-adjuvanting thioether-conjugated glycopeptide-lipopeptide antitumor vaccines for the induction of complement-dependent cytotoxicity against tumor cells.

Glycopeptides of tumor-associated mucin MUC1 are promising target structures for the development of antitumor vaccines. Because these endogenous structures were weakly immunogenic, they were coupled to immune-response-stimulating T-cell epitopes and the Pam(3)Cys lipopeptide to induce strong immune responses in mice. A new thioether-ligation method for the synthesis of two- and three-component vaccines that contain MUC1 glycopeptides as the B-cell epitopes, a T-cell epitope peptide, and the Pam(3)CSK(4) lipopeptide is described. The resulting fully synthetic vaccines were used for the vaccination of mice, either in a liposome with Freund's adjuvant or in aqueous PBS buffer. The three-component vaccines that contained the Tetanus Toxoid P2 T-cell epitope peptide induced strong immune responses, even when administered just in PBS. By activation of the complement-dependent cytotoxicity (CDC) complex, the antisera induced the killing of tumor cells.

Self-adjuvanting synthetic antitumor vaccines from MUC1 glycopeptides conjugated to T-cell epitopes from tetanus toxoid.

The T-helper epitope peptide P30 (green in the scheme) from tetanus toxoid was used as the immunostimulant in MUC1 glycopeptide antitumor vaccines and apparently also acts as a built-in adjuvant. P30-conjugated glycopeptide vaccines containing three glycans in the immunodominant motifs PDTRP and GSTAP induced much stronger immune responses and complement dependent cytotoxicity mediated killing of tumor cells when applied in plain PBS solution without complete Freund's adjuvant.

Effect of fucoidan on gut microbiota and its clinical efficacy in Helicobacter pylori eradication: A randomized controlled trial.

OBJECTIVE: To assess the clinical efficacy of fucoidan-assisted standard quadruple therapy (SQT) in Helicobacter pylori (H. pylori) eradication and the improvement of gut microbiota. METHODS: An open-label randomized controlled trial was conducted at the Affiliated Hospital of Qingdao University in Shandong Province, China. Ninety patients who tested positive for H. pylori were randomized to the standard quadruple therapy (SQT) group (SQ), SQT + fucoidan combination group (SF), and fucoidan + sequential SQT group (FS), respectively. Stool samples were collected for gut microbiota composition at baseline and after treatment. RESULTS: After H. pylori eradication, the relative abundances of most conditional pathogens in the SQ decreased, while those of several beneficial bacteria increased or decreased (P < 0.05). In FS, the abundances of most beneficial bacteria increased gradually from baseline to week 12, while those of the conditional pathogens decreased (P < 0.05). The abundance of Bifidobacterium had a decreasing trend in SQ, but remained unchanged in SF and increased in FS (P < 0.05). The abundances of most beneficial bacteria were significantly higher in FS than in SQ and SF (P < 0.05). Addition of fucoidan enhanced symptom improvement during H. pylori eradication compared with SQT alone. CONCLUSIONS: Fucoidan considerably improved gut dysbiosis during SQT for H. pylori eradication. Gut microbiota can be maintained by the addition of fucoidan before eradication therapy with SQT rather than by concomitant addition with therapy. Fucoidan-assisted SQT could relieve gastrointestinal symptoms during H. pylori eradication.

A totally synthetic, self-assembling, adjuvant-free MUC1 glycopeptide vaccine for cancer therapy.

In the development of vaccines for epithelial tumors, the key targets are MUC1 proteins, which have a variable number of tandem repeats (VNTR) bearing tumor-associated carbohydrate antigens (TACAs), such as Tn and STn. A major obstacle in vaccine development is the low immunogenicity of the short MUC1 peptide. To overcome this obstacle, we designed, synthesized, and evaluated several totally synthetic self-adjuvanting vaccine candidates with self-assembly domains. These vaccine candidates aggregated into fibrils and displayed multivalent B-cell epitopes under mild conditions. Glycosylation of Tn antigen on the Thr residue of PDTRP sequence in MUC1 VNTR led to effective immune response. These vaccines elicited a high level antibody response without any adjuvant and induced antibodies that recognized human breast tumor cells. These vaccines appeared to act through a T-cell independent pathway and were associated with the activation of cytotoxic T cells. These fully synthetic, molecularly defined vaccine candidates had several features that hold promise for anticancer therapy.

Designable Immune Therapeutical Vaccine System Based on DNA Supramolecular Hydrogels.

Immunotherapy is believed to be an ideal method to treat cancer because it can break the immunotolerance of tumor and induce robust immunoresponse. However, constructing a wide antigen-adaptive, easy-handling, and biodegradable system that can recruit and activate antigen-presenting cells (APCs) much effectively is still a challenge. Herein, we show an injectable DNA supramolecular hydrogel vaccine (DSHV) system which could efficiently recruit and activate APCs in vitro and in vivo. The in vitro processes have been visualized by fluorescence microscopy. Through intraperitoneal or subcutaneous injection, the DSHV system can mimic the function of a lymph node where the APCs are recruited and activated by the high local concentration of cytosine-phosphate-guanine. Subsequently, strong immune response and obvious antitumor effects have been obtained. Our findings demonstrated that the DSHV system could serve as a general platform for tumor vaccination and benefit the personalized cancer therapy in the near future.

Prophylactic Vaccine Based on Pyroglutamate-3 Amyloid ß Generates Strong Antibody Response and Rescues Cognitive Decline in Alzheimer's Disease Model Mice.

Clearance of amyloid ß (Aß) by immunotherapy is one of the fancy methods to treat Alzheimer's disease (AD). However, the failure of some clinical trials suggested that there may be something ignored in the past development of immunotherapy. Pyroglutamate-3 Aß (AßpE3-X), which was found to be abundant in the patients' brain, has attracted much attention after the report that AßpE3-42 could serve as a template to exacerbate the aggregation of Aß. In addition, AßpE3-X could not be recognized by the antibodies targeting the N-terminus of Aß, suggesting that AßpE3-X maybe the ignored one. Indeed, passive immunization targeting AßpE3-X has shown some beneficial results, while active immunotherapy has not been extensively studied. In the present study, we designed and synthesized a novel peptide vaccine targeting AßpE3-X, which contains AßpE3-15 as B cell epitope and P2 as T cell epitope. We showed that this vaccine could induce strong antibody response to AßpE3-X. We also showed that prophylactic immunization of AD model mice with our vaccine could reduce Aß plaques and rescue cognitive decline. This new kind of Aß vaccine will open up new directions for AD immunotherapy.

Clearance of the intracellular high level of the tau protein directed by an artificial synthetic hydrolase.

Promoting clearance of intracellular excessive tau is a potential therapeutic strategy for treating Alzheimer's disease. In this work, we designed and synthesized a cyclen-hybrid artificial 'hydrolase' I1-Cu(II) to cleave tau in vitro. Furthermore, a cell-permeable 'hydrolase' I2-Cu(II), derived from I1-Cu(II), was also synthesized to cleave intracellular tau proteins.

Strategy for Designing a Synthetic Tumor Vaccine: Multi-Component, Multivalency and Antigen Modification.

Synthetic tumor vaccines have been proven to be promising for cancer immunotherapy. However, the limitation of the specificity and efficiency of the synthetic tumor vaccines need further improvements. To overcome these difficulties, additional tumor-associated targets need to be identified, and optimized structural designs of vaccines need to be elaborated. In this review, we summarized the main strategies pursued in the design of synthetic tumor vaccines, such as multi-component, multivalency, antigen modification and other possible ways to improve the efficiency of synthetic tumor vaccines.