Supramolecular Peptide Self-Assemblies Facilitate Oral Immunization.

Oral immunization is a promising strategy for preventing and treating gastrointestinal (GI) infections and diseases, as it allows for direct access to the disease site. To elicit immune responses within the GI tract, however, there are many obstacles that oral vaccines must surmount, including proteolytic degradation and thick mucus barriers. Here, we employed a modular self-assembling peptide nanofiber platform to facilitate oral immunization against both peptide and small molecule epitopes. Synthesizing nanofibers with d-amino acids rendered them resistant to proteases in vitro, whereas l-amino acid nanofibers were rapidly degraded. Additionally, the inclusion of peptide sequences rich in proline, alanine, and serine (PAS), increased nanofiber muco-penetration, and accelerated nanofiber transport through the GI tract. Oral immunization with PASylated nanofibers and mucosal adjuvant generated local and systemic immune responses to a peptide epitope but only for l-amino acid nanofibers. Further, we were able to apply this design to also enable oral immunization against a small molecule epitope and illustrated the therapeutic and prophylactic effectiveness of these immunizations in mouse models of colitis. These findings demonstrate that supramolecular peptide self-assemblies have promise as oral vaccines and immunotherapies.

Active immunotherapy for C5a-mediated inflammation using adjuvant-free self-assembled peptide nanofibers.

The terminal protein in the complement cascade C5a is a potent inflammatory molecule and chemoattractant that is involved in the pathology of multiple inflammatory diseases including sepsis and arthritis, making it a promising protein to target with immunotherapies. Active immunotherapies, in which patients are immunized against problematic self-molecules and generate therapeutic antibodies as a result, have received increasing interest as an alternative to traditional monoclonal antibody treatments. In previous work, we have designed supramolecular self-assembling peptide nanofibers as active immunotherapies with defined combinations of B- and T-cell epitopes. Herein, the self-assembling peptide Q11 platform was employed to generate a C5a-targeting active immunotherapy. Two of three predicted B-cell epitope peptides from C5a were found to be immunogenic when displayed within Q11 nanofibers, and the nanofibers were capable of reducing C5a serum concentrations following immunization. Contrastingly, C5a's precursor protein C5 maintained its original concentration, promising to minimize side effects heretofore associated with C5-targeted therapies. Immunization protected mice against an LPS-challenge model of sepsis, and it reduced clinical severity in a model of collagen-antibody induced arthritis. Together, this work indicates the potential for targeting terminal complement proteins with active immunotherapies by leveraging the immunogenicity of self-assembled peptide nanomaterials. STATEMENT OF SIGNIFICANCE: Chronic inflammatory diseases such as rheumatoid arthritis, psoriasis, and inflammatory bowel disease are currently treated primarily with monoclonal antibodies against key inflammatory mediators. While helpful for many patients, they have high non-response rates, are costly, and commonly fail as anti-drug antibodies are raised by the patient. The approach we describe here explores a fundamentally different treatment paradigm: raising therapeutic antibody responses with an active immunotherapy. We employ innovative supramolecular peptide nanomaterials to elicit neutralizing antibody responses against complement component C5a and demonstrate therapeutic efficacy in preclinical mouse models of sepsis and rheumatoid arthritis. The strategy reported may represent a potential alternative to monoclonal antibody therapies.

Engaging natural antibody responses for the treatment of inflammatory bowel disease via phosphorylcholine-presenting nanofibres.

Inflammatory bowel disease lacks a long-lasting and broadly effective therapy. Here, by taking advantage of the anti-infection and anti-inflammatory properties of natural antibodies against the small-molecule epitope phosphorylcholine (PC), we show in multiple mouse models of colitis that immunization of the animals with self-assembling supramolecular peptide nanofibres bearing PC epitopes induced sustained levels of anti-PC antibodies that were both protective and therapeutic. The strength and type of immune responses elicited by the nanofibres could be controlled through the relative valency of PC epitopes and exogenous T-cell epitopes on the nanofibres and via the addition of the adjuvant CpG. The nanomaterial-assisted induction of the production of therapeutic antibodies may represent a durable therapy for inflammatory bowel disease.

Expanding opportunities to engineer mucosal vaccination with biomaterials.

Mucosal vaccines are receiving increasing interest both for protecting against infectious diseases and for inducing therapeutic immune responses to treat non-infectious diseases. However, the mucosal barriers of the lungs, gastrointestinal tract, genitourinary tract, nasal, and oral tissues each present unique challenges for constructing efficacious vaccines. Vaccination through each of these mucosae requires transport through the mucus and across specialized epithelia to reach tissue-specific immune cells and lymphoid structures, necessitating finely tuned and multifunctional strategies. Serving as inspiration for mucosal vaccine design, pathogens have evolved elaborate, diverse, and multipronged approaches to penetrate and infect mucosae. This review is focused on biomaterials-based strategies, many inspired by pathogens, for designing mucosal vaccine platforms. Passive and active technologies are discussed, along with the microbial processes that they seek to mimic.

Subcutaneous nanotherapy repurposes the immunosuppressive mechanism of rapamycin to enhance allogeneic islet graft viability.

Standard oral rapamycin (that is, Rapamune) administration is plagued by poor bioavailability and broad biodistribution. Thus, this pleotropic mammalian target of rapamycin (mTOR) inhibitor has a narrow therapeutic window and numerous side effects and provides inadequate protection to transplanted cells and tissues. Furthermore, the hydrophobicity of rapamycin limits its use in parenteral formulations. Here, we demonstrate that subcutaneous delivery via poly(ethylene glycol)-b-poly(propylene sulfide) polymersome nanocarriers significantly alters rapamycin's cellular biodistribution to repurpose its mechanism of action for tolerance, instead of immunosuppression, and minimize side effects. While oral rapamycin inhibits T cell proliferation directly, subcutaneously administered rapamycin-loaded polymersomes modulate antigen presenting cells in lieu of T cells, significantly improving maintenance of normoglycemia in a clinically relevant, major histocompatibility complex-mismatched, allogeneic, intraportal (liver) islet transplantation model. These results demonstrate the ability of a rationally designed nanocarrier to re-engineer the immunosuppressive mechanism of a drug by controlling cellular biodistribution.

Clinical Relevance of Pre-Existing and Treatment-Induced Anti-Poly(Ethylene Glycol) Antibodies.

Abstract: Poly(ethylene glycol) (PEG) is a nontoxic, hydrophilic polymer that is often covalently attached to proteins, drugs, tissues, or materials; a procedure commonly referred to as PEGylation. PEGylation improves solubility, circulation time, and reduces immunogenicity of therapeutic molecules. Currently, there are 21 PEGylated drugs approved by the Food and Drug Administration (FDA), and more in the developmental stage. In addition to the polymer's applications in the clinic, PEG is widely used as a solvent and emulsifying agent in the formulation of cosmetics, cleaning, and personal care products. Due to the ubiquitous presence of the polymer in everyday products, patients can develop antibodies against PEG (αPEG Abs) that can be problematic when a PEGylated drug is administered. These αPEG Abs can provoke hypersensitivity reactions, accelerated drug clearance, and decreased therapeutic efficacy. Herein, we review how the prevalence of PEG in everyday products has induced αPEG Abs within the general public as well as the effect of these Abs on the performance of PEGylated therapeutics. We will focus on clinical manifestations following the administration of PEGylated drugs. Lay Summary: Poly(ethylene glycol) (PEG) is a polymer found in products including cosmetics, personal care products, cleaning agents, medicine, and food. Due to the prevalence of PEG, people can develop antibodies (αPEG Abs) against the polymer, which recognize PEG as foreign. Of note, PEG is frequently incorporated into drug formulations to improve therapeutic efficacy. Complications can arise when a patient receiving a PEGylated drug has previously developed αPEG Abs from interactions with PEG in everyday products. The presence of high concentrations of αPEG Abs in blood can result in decreased treatment efficacy and allergic reactions to a wide range of therapeutics.

Risk of aspiration pneumonia after an epileptic seizure: a retrospective analysis of 1634 adult patients.

We reviewed the incidence of aspiration pneumonia secondary to seizures in three populations of patients with chronic epilepsy: 733 outpatients seen in an Epilepsy Foundation clinic; 806 adult patients admitted to two university video telemetry units; and 95 institutionalized, profoundly retarded adult patients with chronic epilepsy. Two of the 733 adults who had seizures in the outpatient setting and 2 of the 806 patients who had one or more epileptic seizures in the telemetry units developed aspiration pneumonia. In the 95 institutionalized patients, there were 17 instances of aspiration pneumonia after a generalized seizure and 32 instances of aspiration unrelated to seizures over a 12-month period. Our findings suggest that aspiration pneumonia is not a common complication of seizures in otherwise healthy adults. The increased incidence of aspiration in developmentally delayed individuals seems to derive from a combination of factors. Increased oral secretions, impaired swallowing mechanisms, and difficulty in attaining adequate patient positioning significantly increased the risk of aspiration.

Behaviors mimicking seizures in institutionalized individuals with multiple disabilities and epilepsy: a video-EEG study.

We reviewed 824 video-EEG telemetry requests of institutionalized patients with epilepsy, searching for evaluations of "new seizure types" identified by staff (caregivers, teachers, therapists, LPNs, RNs). Of the 63 newly identified "seizure types," epilepsy was confirmed in 4 (6.3%); 59 represented nonepileptic events. Causes for diagnostic confusion in the profoundly retarded included stereotypic repeated blinking, swallowing, buccolingual movements, spontaneous grimacing, periods of apparent psychomotor arrest and increased muscle tone, dystonic posturing, and irascible personality emerging after reduction of sedatives. Three cases of "startle seizures" were due to dystonic posturing caused by the unexpected contact of body with water during bath. Episodes of decreased daytime alertness ("somnolence") were erroneously attributed to "absence seizures" in eight cases by staff supervising tasks requiring sustained attention (i.e., school, workshop). In less impaired patients, self-stimulation, self-abuse, and ataxia with falls were the more common diagnoses. Simulation of seizures, a somewhat uncommon finding in this population, was the diagnosis in 3 cases. All were high functioning and appeared to simulate seizures to avoid work. Our findings suggest that the de novo appearance of a "new seizure type" in these patients, particularly in cases with a well-established seizure pattern, is uncommon. Four patients in whom the "new event" was confirmed to be epileptic had preexisting secondarily generalized seizures. What the staff identified was the variable clinical progression of seizures probably due to medication changes. Different fragments of the seizure appear to have occurred at different times with variable intensity and duration. A single seizure type may have appeared to be a variety of attacks because of this fragmented presentation.