Abstract Progress in prostate cancer research is presently limited by a shortage of reliable in vitro model systems. The authors describe a novel self‐assembling peptide, bQ13, which forms nanofibers and gels useful for the 3D culture of prostate cancer spheroids, with improved cytocompatibility compared to related fibrillizing peptides. The mechanical properties of bQ13 gels can be controlled by adjusting peptide concentration, with storage moduli ranging between 1 and 10 kPa. bQ13's ability to remain soluble at mildly basic pH considerably improved the viability of encapsulated cells compared to other self‐assembling nanofiber‐forming peptides. LNCaP cells formed spheroids in bQ13 gels with similar morphologies and sizes to those formed in Matrigel or RADA16‐I. Moreover, prostate‐specific antigen (PSA) is produced by LNCaP cells in all matrices, and PSA production is more responsive to enzalutamide treatment in bQ13 gels than in other fibrillized peptide gels. bQ13 represents an attractive platform for further tailoring within 3D cell culture systems.
Current treatments for chronic immune-mediated diseases such as psoriasis, rheumatoid arthritis, or Crohn's disease commonly rely on cytokine neutralization using monoclonal antibodies; however, such approaches have drawbacks. Frequent repeated dosing can lead to the formation of anti-drug antibodies and patient compliance issues, and it is difficult to identify a single antibody that is broadly efficacious across diverse patient populations. As an alternative to monoclonal antibody therapy, anti-cytokine immunization is a potential means for long-term therapeutic control of chronic inflammatory diseases. Here we report a supramolecular peptide-based approach for raising antibodies against IL-17 and demonstrate its efficacy in a murine model of psoriasis. B-cell epitopes from IL-17 were co-assembled with the universal T-cell epitope PADRE using the Q11 self-assembling peptide nanofiber system. These materials, with or without adjuvants, raised antibody responses against IL-17. Exploiting the modularity of the system, multifactorial experimental designs were used to select formulations maximizing titer and avidity. In a mouse model of psoriasis induced by imiquimod, unadjuvanted nanofibers had therapeutic efficacy, which could be enhanced with alum adjuvant but reversed with CpG adjuvant. Measurements of antibody subclass induced by adjuvanted and unadjuvanted formulations revealed strong correlations between therapeutic efficacy and titers of IgG1 (improved efficacy) or IgG2b (worsened efficacy). These findings have important implications for the development of anti-cytokine active immunotherapies and suggest that immune phenotype is an important metric for eliciting therapeutic anti-cytokine antibody responses.
Abstract Biotherapeutics have the potential to elicit unwanted immune responses that can lead to the production of anti-drug antibodies (ADA). It is critical that ADA responses are detected, characterized, and monitored to understand the safety and efficacy of a drug. ADA samples must remain stable in long- and short-term storage conditions to ensure reliable analysis. Whereas the stability of anti-vaccine antibodies has been well-studied, there are few reports examining the stability of anti-therapeutic antibodies using clinical samples. In this study, ADA samples from four clinical trials of antibody therapeutics were found to be stable after long-term storage (1–10 years) at -80°C and short-term storage (24 h to two weeks) at 4°C, 22°C, and 37°C. In addition, samples were stable after 16 freeze/thaw cycles. The results demonstrate the stability of ADA in clinical samples under various conditions. Consequently, the results observed herein suggest that the routine assessment of ADA sample stability may not be warranted. Graphical Abstract
Subunit vaccines inducing antibodies against tumor-specific antigens have yet to be clinically successful. Here, we use a supramolecular α-helical peptide nanofiber approach to design epitope-specific vaccines raising simultaneous B cell, CD8
Significance Current treatments for chronic inflammatory conditions rely on biologic drugs, commonly monoclonal antibodies that interfere with inflammatory signaling pathways. These drugs have made enormous contributions to the treatment of inflammatory diseases but still possess considerable drawbacks, including high cost that limits access in low-resource settings, the requirement for regularly repeated injections, and uneven efficacy. As an alternative to such biologics, active immunotherapies, in which an individual is induced to generate their own therapeutic antibodies, offer considerable potential advantages. Here, we report chemically defined nanomaterials inducing therapeutic responses in two models of inflammation in mice. The materials were produced by coassembling defined T cell epitopes, B cell epitopes, and an engineered fragment of complement protein C3dg into defined nanomaterials.
A major challenge in developing an effective vaccine against HIV-1 is the genetic diversity of its viral envelope. Because of the broad range of sequences exhibited by HIV-1 strains, protective antibodies must be able to bind and neutralize a widely mutated viral envelope protein. No vaccine has yet been designed which induces broadly neutralizing or protective immune responses against HIV in humans. Nanomaterial-based vaccines have shown the ability to generate antibody and cellular immune responses of increased breadth and neutralization potency. Thus, we have developed supramolecular nanofiber-based immunogens bearing the HIV gp120 envelope glycoprotein. These immunogens generated antibody responses that had increased magnitude and binding breadth compared to soluble gp120. By varying gp120 density on nanofibers, we determined that increased antigen valency was associated with increased antibody magnitude and germinal center responses. This study presents a proof-of-concept for a nanofiber vaccine platform generating broad, high binding antibody responses against the HIV-1 envelope glycoprotein.
Supramolecular materials composed of proteins and peptides have been receiving considerable attention toward a range of diseases and conditions from vaccines to drug delivery. Owing to the relative newness of this class of materials, the bulk of work to date has been preclinical. However, examples of approved treatments particularly in vaccines, dentistry, and hemostasis demonstrate the translational potential of supramolecular polypeptides. Critical milestones in the clinical development of this class of materials and currently approved supramolecular polypeptide therapies are described in this study. Additional examples of not-yet-approved materials that are steadily advancing toward clinical use are also featured. Spherical assemblies such as virus-like particles, designed protein nanoparticles, and spherical peptide amphiphiles are highlighted, followed by fiber-forming systems such as fibrillizing peptides, fiber-forming peptide-amphiphiles, and filamentous bacteriophages.
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