Self-adjuvanting vaccine against group A streptococcus: application of fibrillized peptide and immunostimulatory lipid as adjuvant

Peptides are of great interest to be used as vaccine antigens due to their safety, ease of manufacturing and specificity in generating immune response. There have been massive discoveries of peptide antigens over the past decade. However, peptides alone are poorly immunogenic, which demand co-administration with strong adjuvant to enhance their immunogenicity. Recently, fibril-forming peptides such as Q11 and lipoamino acid-based carrier have been identified to induce substantial immune responses when covalently linked to peptide epitope. In this study, we have incorporated either Q11 or lipoamino acids to a peptide epitope (J14) derived from M protein of group A streptococcus to develop self-adjuvanting vaccines. J14, Q11 and lipoamino acids were also conjugated together in a single vaccine construct in an attempt to evaluate the synergy effect of combining multiple adjuvants. Physicochemical characterization demonstrated that the vaccine constructs folded differently and self-assembled into nanoparticles. Significantly, only vaccine constructs containing double copies of lipoamino acids (regardless in conjugation with Q11 or not) were capable to induce significant dendritic cells uptake and subsequent J14-specific antibody responses in non-sizes dependent manners. Q11 had minimal impact in enhancing the immunogenicity of J14 even when it was used in combination with lipoamino acids. These findings highlight the impact of lipoamino acids moiety as a promising immunostimulant carrier and its number of attachment to peptide epitope was found to have a profound effect on the vaccine immunogenicity

HER2/neu-based peptide vaccination-pulsed with B-cell epitope induced efficient prophylactic and therapeutic antitumor activities in TUBO breast cancer mice model

Breast cancer is the most common invasive cancer diagnosed among women. A cancer vaccine has been recognized as a form of immunotherapy with a prominent position in the prevention and treatment of breast cancer. The majority of current breast cancer vaccination strategies aim to stimulate antitumor T-cell responses of the HER2/neu oncogene, which is abnormally expressed in breast cancer cells. However, the role of the B-cell humoral response is often underappreciated in the cancer vaccine design. We have advanced this idea by elucidating the role of B-cells in cancer vaccination by designing a chimeric antigenic peptide possessing both cytotoxic T lymphocytes (GP2) and B-cell (P4) peptide epitopes derived from HER2/neu. The chimeric peptide (GP2–P4) was further conjugated to a carrier protein (KLH), forming a KLH–GP2–P4 conjugate. The immunogenicity of KLH–GP2–P4 was compared with KLH–GP2 (lacking the B-cell epitope) in BALB/c mice. Mice immunized with KLH–GP2–P4 elicited more potent antigen-specific neutralizing antibodies against syngeneic TUBO cells (cancer cell line overexpressing HER2/neu) that was governed by a balanced Th1/Th2 polarization in comparison to KLH–GP2. Subsequently, these immune responses led to greater inhibition of tumor growth and longer survival in TUBO tumor-bearing mice in both prophylactic and therapeutic challenge experiments. Overall, our data demonstrated that the B-cell epitope has a profound effect in orchestrating an efficacious antitumor immunity. Thus, a multi-epitope peptide vaccine encompassing cytotoxic T-lymphocytes, T-helper and B-cell epitopes represents a promising strategy in developing cancer vaccines with a preventive and therapeutic modality for the effective management of breast cancer

Antibiotic biosynthesis pathways from endophytic streptomyces SUK 48 through metabolomics and genomics approaches

Streptomyces sp. has been known to be a major antibiotic producer since the 1940s. As the number of cases related to resistance pathogens infection increases yearly, discovering the biosynthesis pathways of antibiotic has become important. In this study, we present the streamline of a project report summary; the genome data and metabolome data of newly isolated Streptomyces SUK 48 strain are also analyzed. The antibacterial activity of its crude extract is also determined. To obtain genome data, the genomic DNA of SUK 48 was extracted using a commercial kit (Promega) and sent for sequencing (Pac Biosciences technology platform, Menlo Park, CA, USA). The raw data were assembled and polished using Hierarchical Genome Assembly Process 4.0 (HGAP 4.0). The assembled data were structurally predicted using tRNAscan-SE and rnammer. Then, the data were analyzed using Kyoto Encyclopedia of Genes and Genomes (KEGG) database and antiSMASH analysis. Meanwhile, the metabolite profile of SUK 48 was determined using liquid chromatographymass spectrophotometry (LC-MS) for both negative and positive modes. The results showed that the presence of kanamycin and gentamicin, as well as the other 11 antibiotics. Nevertheless, the biosynthesis pathways of aurantioclavine were also found. The cytotoxicity activity showed IC50 value was at 0.35 � 1.35 mg/mL on the cell viability of HEK 293. In conclusion, Streptomyces sp. SUK 48 has proven to be a non-toxic antibiotic producer such as auranticlavine and gentamicin

Peptide-Based Vaccine against Breast Cancer: Recent Advances and Prospects

Breast cancer is considered the second-leading cancer after lung cancer and is the most prevalent cancer among women globally. Currently, cancer immunotherapy via vaccine has gained great attention due to specific and targeted immune cell activity that creates a potent immune response, thus providing long-lasting protection against the disease. Despite peptides being very susceptible to enzymatic degradation and poor immunogenicity, they can be easily customized with selected epitopes to induce a specific immune response and particulate with carriers to improve their delivery and thus overcome their weaknesses. With advances in nanotechnology, the peptide-based vaccine could incorporate other components, thereby modulating the immune system response against breast cancer. Considering that peptide-based vaccines seem to show remarkably promising outcomes against cancer, this review focuses on and provides a specific view of peptide-based vaccines used against breast cancer. Here, we discuss the benefits associated with a peptide-based vaccine, which can be a mainstay in the prevention and recurrence of breast cancer. Additionally, we also report the results of recent trials as well as plausible prospects for nanotechnology against breast cancer

Towards the development of synthetic antibiotics: designs inspired by natural antimicrobial peptides

Virtually every living organism produces gene-encoded antimicrobial peptides (AMPs) that provide an immediate defence against pathogen invasion. Many AMPs have been isolated and used as antibiotics that are effective against multidrug-resistant bacteria. Although encouraging, AMPs have such poor drug-like properties that their application for clinical use is restricted. In turn, this has diverted research to the development of synthetic molecules that retain the therapeutic efficacy of AMPs but are endowed with greater biological stability and safety profiles. Most of the synthetic molecules, either based on a peptidic or non-peptidic scaffold, have been designed to mimic the amphiphilic properties of native AMPs, which are widely believed to be the key determinant of their antibacterial activity. In this review, the structural, chemical and biophysical features that govern the biological activities of various synthetic designs are discussed extensively. Recent innovative approaches from the literature that exhibit novel concepts towards the development of new synthetic antibacterial agents, including the engineered delivery platform incorporated with AMP mimetics, are also emphasised

Influence of the oil phase on the wound healing activity of sea cucumber extract-based cream formulations

Sea cucumbers are attractive marine natural sources as they are enriched with functional biomaterials that can contribute in accelerating wound healing. The present study was carried out to prepare cream formulations comprising extract of sea cucumber with different type of oil phase, namely F1 (olive oil), F2 (tea tree oil) and F3 (lemongrass oil) to assess the influence of the oil on the physicochemical properties and the wound healing efficacy of the creams. The formulated creams showed satisfactory physicochemical characteristics such as homogeneity, spreadability, rheology, pH, and showed no evidence of phase separation even when the creams were kept at extreme conditions. The ex vivo release profile of sea cucumber extract from the formulated creams was determined by using a Franz diffusion cells. F3 demonstrated a constant and yield the highest release percentage of sea cucumber extract, followed by F2 and F1. Topical application of the formulated creams on the excision wound in rats showed a significant wound healing efficacy compared to the control group. Among the creams formulation, F1 demonstrated a significantly higher rate of wound closure compared to F2, F3, and positive control. The wound healing efficacy of the formulated creams were not dependent on the ability of the oils in promoting skin permeation for the release of sea cucumber extract. This study depicted that lemongrass oil acted as a good skin permeation enhancer for the release of sea cucumber extract while olive oil worked in a more synergistic manner with sea cucumber extract in promoting wound healing

Recent progress in adjuvant discovery for peptide-based subunit vaccines

Peptide-based subunit vaccines are of great interest in modern immunotherapy as they are safe, easy to produce and well defined. However, peptide antigens produce a relatively weak immune response, and thus require the use of immunostimulants (adjuvants) for optimal efficacy. Developing a safe and effective adjuvant remains a challenge for peptide-based vaccine design. Recent advances in immunology have allowed researchers to have a better understanding of the immunological implication of related diseases, which facilitates more rational design of adjuvant systems. Understanding the molecular structure of the adjuvants allows the establishment of their structure-activity relationships which is useful for the development of next-generation adjuvants. This review summarizes the current state of adjuvants development in the field of synthetic peptide-based vaccines. The structural, chemical and biological properties of adjuvants associated with their immunomodulatory effects are discussed

An Overview of Recent Developments in the Application of Antigen Displaying Vaccine Platforms: Hints for Future SARS-CoV-2 VLP Vaccines

Recently, a great effort has been devoted to studying attenuated and subunit vaccine development against SARS-CoV-2 since its outbreak in December 2019. It is known that diverse virus-like particles (VLPs) are extensively employed as carriers to display various antigenic and immunostimulatory cargo modules for vaccine development. Single or multiple antigens or antigenic domains such as the spike or nucleocapsid protein or their variants from SARS-CoV-2 could also be incorporated into VLPs via either a genetic or chemical display approach. Such antigen display platforms would help screen safer and more effective vaccine candidates capable of generating a strong immune response with or without adjuvant. This review aims to provide valuable insights for the future development of SARS-CoV-2 VLP vaccines by summarizing the latest updates and perspectives on the vaccine development of VLP platforms for genetic and chemical displaying antigens from SARS-CoV-2

Comparison of fluorinated and nonfluorinated lipids in self-adjuvanting delivery systems for peptide-based vaccines

Safe immunostimulants (adjuvants) are essential for the development of highly potent peptide-based vaccines. This study examined for the first time whether fluorinated lipids could stimulate humoral immunity in vivo when conjugated to peptide antigen. The impact of fluorination on humoral immunity was tested using a library of peptide-based vaccine candidates against the group A streptococcus (GAS). The fluorinated constructs stimulated similar mouse IgG titers to those elicited by complete Freund’s adjuvant (CFA) and were higher than those produced in mice that received the nonfluorinated constructs

Immunoinformatics-guided selection of immunogenic peptides from betanodavirus induce antigen-specific antibody production in hybrid grouper, Epinephelus fuscoguttatus x Epinephelus lanceolatus

Betanodavirus is a significant pathogen that causes viral nervous necrosis (VNN) in a wide range of fish species. It could cause up to 100 mortality in the infected farmed fish, especially at the larval stage. Red-Spotted Grouper Nervous Necrosis Virus (RGNNV), one of the betanodavirus genotypes, has been proven to have a wide range of host-compatibility across warm-water fish species. To date, there is no viable strategy to combat this virus infection, but vaccination approach is known to be effective against infectious diseases. Thus, current study aimed to identify immunogenic peptides as potential subunit vaccine candidates against grouper betanodavirus. Nucleotide sequences of the grouper nervous necrosis virus were retrieved from the National Center for Biotechnology Information database. B- and T-cell epitopes were predicted using the Immune Epitope Database analysis resource and the NetCTL 1.2 server, respectively. The predicted B- and T-cell epitopes were analysed for its respective antigenicity, immunogenicity, physico-chemical properties, and surface accessibility. Selected epitopes were then synthesized for immunization assay to examine antigen-specific antibody production in the immunized grouper. Five epitopes (one B-cell and four T-cell epitopes) were selected based on the immunogenicity score. The B-cell epitope has the highest immunogenicity score of 0.9333. Physico-chemical properties analysis of the B-cell epitope shown highest GRAVY score of 0.516 and was predicted to possess the longest estimated half-life of 30 h. Structural analysis has shown that the B-cell epitope possesses the largest accessible surface on the virus particle. Immunization of grouper with the selected B-cell epitope induced the highest antigen-specific antibody production as compared to grouper that was immunized with the selected T-cell epitope. This study demonstrated the feasibility of reverse vaccinology approach in the selection and design of immunogenic peptides against NNV in grouper to serve as the potential vaccine candidate. © 2023 Elsevier B.V