You will be shown an abstract from a biomedical research paper. Given this abstract, your task is to extract all unique entities of the following types: ["HealthCareActivity", "InjuryOrPoisoning", "BodySubstance", "IntellectualProduct", "AnatomicalStructure", "SpatialConcept", "Chemical", "Bacterium", "MedicalDevice", "Organization", "BiomedicalOccupationOrDiscipline", "Finding", "BiologicFunction", "Virus", "ResearchActivity", "ClinicalAttribute", "PopulationGroup", "Eukaryote", "BodySystem", "Food", "ProfessionalOrOccupationalGroup"].

Please return the output as a JSON object of the format: {"Virus": ["HIV", ...], "Bacterium": ["MRSA", ...], "AnatomicalStructure": ["Lung", ...], "BodySystem": ["CNS", ...], "BodySubstance": ["Serum", ...], "Finding": ["Headache", ...], "InjuryOrPoisoning": ["Fracture", ...], "BiologicFunction": ["Death", ...], "HealthCareActivity": ["Biopsy", ...], "ResearchActivity": ["Clinical trial", ...], "MedicalDevice": ["Lenses", ...], "SpatialConcept": ["Camps", ...], "BiomedicalOccupationOrDiscipline": ["Forensic medicine", ...], "Organization": ["WHO", ...], "ProfessionalOrOccupationalGroup": ["Provider", ...], "PopulationGroup": ["Swimmers", ...], "Chemical": ["Gold", ...], "Food": ["Rice", ...], "IntellectualProduct": ["RPAM", ...], "ClinicalAttribute": ["Biomarker", ...], "Eukaryote": ["Dogs", ...]}. The keys should be entity types and values should be lists of extracted entities belonging to the corresponding type. If you cannot find entities belonging to a specific type, the value should be [].

Only output the JSON object and do not include any additional text.

Abstract:

Allergen Valency, Dose, and FcεRI Occupancy Set Thresholds for Secretory Responses to Pen a 1 and Motivate Design of Hypoallergens Ag -mediated crosslinking of IgE - FcεRI complexes activates mast cells and basophils, initiating the allergic response. Of 34 donors recruited having self-reported shrimp allergy, only 35% had significant levels of shrimp-specific IgE in serum and measurable basophil secretory responses to rPen a 1 (shrimp tropomyosin). We report that degranulation is linked to the number of FcεRI occupied with allergen-specific IgE, as well as the dose and valency of Pen a 1. Using clustered regularly interspaced palindromic repeat-based gene editing, human RBL(rαKO) cells were created that exclusively express the human FcεRIα subunit. Pen a 1 - specific IgE was affinity purified from shrimp - positive plasma. Cells primed with a range of Pen a 1 - specific IgE and challenged with Pen a 1 showed a bell-shaped dose response for secretion, with optimal Pen a 1 doses of 0.1-10 ng/ml. Mathematical modeling provided estimates of receptor aggregation kinetics based on FcεRI occupancy with IgE and allergen dose. Maximal degranulation was elicited when ∼2700 I gE - FcεRI complexes were occupied with specific IgE and challenged with Pen a 1 (IgE epitope valency of ≥8), although measurable responses were achieved when only a few hundred FcεRI were occupied. Prolonged periods of pepsin -mediated Pen a 1 proteolysis, which simulates gastric digestion, were required to diminish secretory responses. Recombinant fragments (60-79 aa), which together span the entire length of tropomyosin, were weak secretagogues. These fragments have reduced dimerization capacity, compete with intact Pen a 1 for binding to IgE - FcεRI complexes, and represent a starting point for the design of promising hypoallergens for immunotherapy.
{"AnatomicalStructure": ["basophils", "mast cells", "basophil"], "Bacterium": [], "BiologicFunction": ["secretory", "proteolysis", "responses", "dimerization", "shrimp allergy", "digestion", "secretory responses", "response for secretion", "allergic response", "receptor aggregation", "Secretory Responses"], "BiomedicalOccupationOrDiscipline": [], "BodySubstance": ["serum", "plasma"], "BodySystem": [], "Chemical": ["IgE", "Fc\u03b5RI\u03b1", "Pen a 1", "shrimp-specific IgE", "Ag", "Allergen", "complexes", "pepsin", "allergen-specific IgE", "specific IgE", "epitope", "hypoallergens", "gE", "tropomyosin", "Hypoallergens", "allergen", "Fc\u03b5RI"], "ClinicalAttribute": [], "Eukaryote": ["shrimp"], "Finding": ["positive"], "Food": [], "HealthCareActivity": ["immunotherapy"], "InjuryOrPoisoning": [], "IntellectualProduct": ["Mathematical modeling"], "MedicalDevice": [], "Organization": [], "PopulationGroup": [], "ProfessionalOrOccupationalGroup": [], "ResearchActivity": ["clustered regularly interspaced palindromic repeat-based gene editing", "self-reported"], "SpatialConcept": [], "Virus": []}