Patterns of aeroallergen sensitization in asthma patients identified by latent class analysis: A cross-sectional study in China

B-cell epitope peptide immunotherapy alleviates chitin-binding protein-induced type 2 airway inflammation in a Blomia tropicalis-murine model

BACKGROUND

Peptide immunotherapy (PIT) offers a safe and effective treatment with minimal side effects. This study aims to identify B-cell epitopes of a novel allergen from Blomia tropicalis (B. tropicalis), specifically the Chitin-binding domain type 2 (ChtBD2) protein, and evaluate the therapeutic effects of peptide treatment in a murine model.

METHODS

Using Alphafold2, the 3D structure of ChtBD2 was constructed. AI-based and traditional computational tools predicted the predominant B-cell epitopes. Twelve synthesized peptides were assessed for allergenicity and immunogenicity. A murine model of B. tropicalis-induced allergic airway inflammation mimicking human atopic asthma was developed and analyzed.

RESULTS

Predominant B-cell epitopes of ChtBD2 were identified as promising IgE-binding domains. Peptide 1 (PT1: 1-15) showed significant IgE-binding activity and the highest inhibition rate in competitive IgE-binding assays. PT1 upregulated IL-4, IL-13, and CD63 in B. tropicalis-sensitized patients' PBMCs and basophils, respectively. Notably, IT groups showed reduced lung cellular infiltration and type 2 cytokine expression in BALF. Specific IgE levels were reduced, with a decline in the IgG1/IgG2a ratio.

CONCLUSIONS

This study represents the first AI-facilitated development of a B-cell epitope-based ChtBD2 PIT, showing promise as an immunotherapy for B. tropicalis-allergic patients with reduced allergenicity and high immunogenicity in inducing IgG-blocking antibodies.

CLINICAL TRIAL

Not applicable.

Chinese expert consensus on allergen component resolved diagnosis

BACKGROUND

Allergen component resolved diagnosis (CRD) is a method for identifying specific protein molecules that cause hypersensitivity. Unlike traditional methods that use crude allergen extracts containing multiple component species, CRD focuses on individual allergen protein molecules for more precise diagnosis. The World Allergy Organization (WAO) recommends CRD as a supplement to clinical history and allergen extract testing, and in some cases, it can replace crude extract tests.

METHODS

CRD involves the use of natural or recombinant proteins to detect specific IgE antibodies directed at individual allergenic components. This method allows for a more detailed analysis of a patient's allergic response compared to the use of whole allergen extracts. The Allergy Prevention and Control Specialty Committee of the Chinese Preventive Medicine Association, in collaboration with multidisciplinary experts, developed an expert consensus that incorporates the consensus of the European Academy of Allergy and Clinical Immunology (EAACI), WAO, and important domestic literature on CRD in recent years.

RESULTS

The consensus aims to standardize the algorithm of allergen diagnosis and provides a reference for clinical practice. It also offers guidance for clinicians on the common protein families identified by CRD, the scenarios where CRD is applicable, and the significance of detecting common allergen components.

CONCLUSIONS

Despite its potential, CRD is not widely used in clinical practice in China due to the lack of allergen component reagents and a general unawareness among clinicians about CRD's application and interpretation of test results. The expert consensus developed by the Chinese Preventive Medicine Association aims to address this gap and enhance the clinical application of CRD in China.

Profile of cross-reactivity to common pollen allergens in Northwest China based on component resolved diagnosis

The prevalence of allergic diseases such as Allergic Rhinitis and Asthma is steadily increasing globally, with pollen allergy being one of the most significant sensitizing factors. However, the cross-reactivity of different pollen allergies remains unclear, posing challenges in the diagnosis and treatment of individuals with multiple sensitivities. In this study, the Component Resolved Diagnosis technique was performed to simultaneously measure the specific IgE concentrations of 52 patients against Art v and its components (Art v 1), Phl p and its components (Phl p 1, Phl p 4, Phl p 5, Phl p 6, Phl p 7, Phl p 12), Bet v and its components (Bet v 1, Bet v 2), Amb a and its component (Amb a 1), and Amb p. Additionally, sIgE inhibition tests were conducted by Art v, Phl p, and Bet v extracts. Among Art v-positive patients, 64.6% showed positivity for Art v 1. In Phl p-positive patients, Phl p 12 had the highest positivity rate (75.0%). Among Bet v-positive patients, 75.6% exhibited positivity for Bet v 2, whereas for Amb a and Amb p-positive patients, 23.7% and 29.0% respectively showed positivity for Amb a 1. The sIgE inhibition assays results revealed that Art v extract had inhibition rates greater than 73.2% against Phl p and its component Phl p 12, as well as Bet v and its component Bet v 2. Simultaneously, Phl p extract showed inhibition rates of 80.70-89.87% against Phl p 12, Bet v and Bet v 2. Bet v extract showed inhibition rates ranging from 21.9 to 59.8% against Phl p and Bet v 2, with a better inhibition rate (76.80%) against Phl p 12. In conclusion, Art v 1 is identified as the principal component of Art v. The profilin proteins of Phl p and Bet v (Phl p 12 and Bet v 2), are implicated as potential cross-reactive elements contributing to polysensitization in patients with respiratory allergies in the Northwest region of China. This cross-reactivity leads to a shared sensitization mechanism among pollen allergens such as Art v, Phl p, and Bet v.

Identification of rBlo t 41 with a chitin-binding type-2 domain: A novel major allergen from Blomia tropicalis

BACKGROUND

Blomia tropicalis (B. tropicalis) has been reported to impose an increased risk of allergic diseases. However, few characteristics of the unknown allergen components responsible for B. tropicalis allergy and clinical relevance have been fully identified.

METHODS

We synthesized and characterized the physicochemical properties and cross-reactivity of the newly discovered recombinant B. tropicalis group 41 allergen (rBlo t 41). Subsequently, sera were collected from 107 B. tropicalis allergic subjects to evaluate the prevalence of the rBlo t 41. Lastly, its allergenicity was tested in humans by basophil activation assays, and in mice by a model of allergic asthma.

RESULTS

The mature protein of rBlo t 41 was described as 104 amino acids long and 15.8 kDa, and its limited cross-reactivity was observed between allergens of house dust mites (HDM). Sensitization rate of rBlo t 41 (56.07 %) was lower than rBlo t 2 (76.29 %) and rBlo t 5 (69.07 %) in our study. Besides, rBlo t 41 elicited CD63 upregulation in basophils, whereas rBlo t 41-sensitized mice generated rBlo t 41-IgE and developed allergic airway inflammation after allergen exposure. Of note, component-based tests showed a high area under curve value (AUC = 0.75) of rBlo t 41, displaying its favorable diagnostic potential in B. tropicalis allergy.

CONCLUSIONS

rBlo t 41 was identified as a candidate novel major allergen with good diagnostic potential in B. tropicalis sensitization. Additionally, we provided strong evidence about rBlo t 41 on the clinically relevant manifestations in B. tropicalis allergies, conducive to facilitating the development of component-resolved diagnosis.