Nanoparticles can be used to accomplish antigen-specific immune tolerance in allergic and autoimmune disease. The available options for custom-designing tolerogenic nanoparticles (NPs) include the use of nanocarriers that introduce antigens into natural tolerogenic environments, such as the liver, where antigen presentation promotes tolerance to self or foreign antigens. Here, we demonstrate the engineering of a biodegradable polymeric poly (lactic-co-glycolic acid) (PLGA) nanocarrier for the selective delivery of the murine allergen, ovalbumin (OVA), to the liver. This was accomplished by developing a series of NPs in the 200-300 nm size range as well as decorating particle surfaces with ligands that targets scavenger and mannose receptors on specialized tolerogenic liver sinusoidal endothelial cells (LSECs). LSECs represent a major antigen presenting cell (APC) type in the liver capable of generating regulatory T-cells (Tregs). In vitro exposure of LSECs to NP OVA induced abundant TGF-β, IL-4 and IL-10 production, which

The targeting of natural tolerogenic liver sinusoidal endothelial cells (LSEC) by nanoparticles (NPs), decorated with a stabilin receptor ligand, is capable of generating regulatory T-cells (Tregs), which can suppress antigen-specific immune responses, including to ovalbumin (OVA), a possible food allergen. In this regard, we have previously demonstrated that OVA-encapsulating poly(lactic-co-glycolic acid) (PLGA) nanoparticles eliminate allergic airway inflammation in OVA-sensitized mice, prophylactically and therapeutically. A competing approach is a nanocarrier platform that incorporates pharmaceutical agents interfering in mTOR (rapamycin) or NF-κB (curcumin) pathways, with the ability to induce a tolerogenic state in nontargeted antigen-presenting cells system-wide. First, we compared OVAencapsulating, LSEC-targeting tolerogenic nanoparticles (TNPs) with nontargeted NPs incorporating curcumin and rapamycin (Rapa) in a murine eosinophilic airway inflammation model, which is Treg-sensitive. This demonstrated roughly similar tolerogenic effects on allergic airway inflammation by stabilin-targeting NP OVA versus nontargeted NPs delivering OVA plus Rapa. Reduction in eosinophilic inflammation and TH2-mediated immune responses in the lung was accompanied by increased Foxp3 + Treg recruitment and TGF-β production in both platforms. As OVA incorporates IgE-binding as well as non-IgE-binding epitopes, the next experiment explored the possibility of obtaining immune tolerance by non-anaphylactic T-cell epitopes. This was accomplished by incorporating OVA 323−339 and OVA 257−264 epitopes in liver-targeting NPs to assess the prophylactic and therapeutic impact on allergic inflammation in transgenic OT-II mice. Importantly, we demonstrated that the major histocompatibility complex (MHC)-II binding (former) but not the MHC-I binding (latter) epitope interfered in allergic airway inflammation, improving TNP OVA efficacy. The epitope-specific effect was transduced by TGF-β-producing Tregs. In the final phase of experimentation, we used an OVA-induced anaphylaxis model to demonstrate that targeted delivery of OVA and its MHC-II epitope could significantly suppress the anaphylaxis symptom score, mast cell release, and the late-phase inflammatory response. In summary, these results demonstrate comparable efficacy of LSEC-targeting versus pharmaceutical PLGA nanoparticles, as well as the ability of T-cell epitopes to achieve response outcomes similar to those of the intact allergens.

IntroductionLaryngeal sensory function in healthy adults was assessed through the delivery of tactile stimuli using Cheung–Bearelly monofilaments.Methods37 healthy adults were recruited with 340 tactile stimuli analyzed. Four calibrated tactile stimuli were delivered to three laryngeal sites: false vocal fold (FVF), aryepiglottic fold (AEF), and lateral pyriform sinus (LPS). Primary outcome was the elicitation of laryngeal adductor reflex (LAR). Secondary outcomes were gag, patient‐reported laryngeal sensation (PRLS), and perceptual strength. Analysis was performed with mixed effects logistic regression modeling.ResultsPositive LAR was observed in 35.7%, 70.2%, and 91.2% of stimuli at LPS, AEF, and FVF respectively. LAR rates were significantly associated with laryngopharyngeal subsite (p < 0.001), tactile force (p = 0.001), age (p = 0.022) and sex (p = 0.022). LAR, gag, PRLS, and perceptual strength significantly increased as a more medial laryngeal subsite was stimulated and as stimulus force increased. Each of the ten years of age increase was associated with 19% reduction in odds of LAR (aOR = 0.81, 95% CI [0.68, 0.97]; p = 0.022). Male gender was associated with a 55% reduction in odds of LAR (aOR = 0.45, 95% CI [0.23, 0.89]; p = 0.022).ConclusionLAR elicitation capability decreases in the male gender, aging, and a more lateral subsite. This study provides insight into the pathophysiology of hypo‐ and hyper‐sensitive laryngeal disorders and is paramount to making accurate diagnostic assessments and finding novel treatment options for various laryngological disorders. Laryngoscope, 133:2525–2532, 2023