In Vitro Characterization of the Immune Response to an Epitope Ensemble Vaccine Against Rhinovirus in Pediatric Asthma and Adults With Chronic Obstructive Pulmonary Disease: Protocol for an Observational and Exploratory Study

Abstract

Background: Human rhinoviruses (HRVs) are the leading cause of upper respiratory tract infections, responsible for over half of all such infections. Infection rates among young children can reach as high as 8-12 episodes per year. While HRV infections typically result in mild common colds, they can also lead to more severe respiratory conditions, often in conjunction with bacterial coinfections. In addition, HRVs are implicated in the exacerbation of obstructive respiratory diseases, including asthma and chronic obstructive pulmonary disease (COPD). T-cell responses play a crucial role in the immune defense against HRV. However, in patients with obstructive respiratory diseases, altered or dysregulated T-cell responses to HRV may not only fail to efficiently eliminate the virus but can also exacerbate inflammation and airway remodeling. Therefore, a deeper understanding of T-cell-mediated responses in the context of HRV infection, especially in vulnerable populations like those with COPD, is critical. It can provide new insights into mechanisms of both protection and disease exacerbation, potentially guiding the development of targeted therapies or vaccines that enhance protective immunity while minimizing harmful inflammation.

Objective: This study aims to (1) determine the population-wide coverage of HRV-specific T-cell responses, (2) characterize HRV-specific T-cell recall responses in disease cohorts compared to age-match healthy controls, and (3) identify biomarkers of protection and susceptibility within disease cohorts through a comparative analysis.

Methods: Participants with asthma and those with COPD, aged 5-15 and 40-70 years, respectively, will be recruited alongside healthy age-matched controls. Peripheral blood samples will be collected following informed consent from adult participants and from parents or guardians of minors, as applicable. Clinical, demographic, immunological, and genetic responses will be assessed both prior to and following in vitro stimulation with a pool of HRV-specific T-cell epitopes. Flow cytometry and functional assays will be used to analyze T-cell responses to HRV epitopes in the context of obstructive respiratory diseases.

Results: This study was funded in January 2023 by the Ministry of Science and Innovation of Spain. The primary aim of the study was achieved within the same year. Recruitment for the secondary and tertiary aims is currently ongoing. Preliminary findings highlight the potential significance of HRV-specific T-cell responses in individuals with asthma and those with COPD. A detailed characterization of these immune responses will provide critical insights into host-pathogen interactions and may serve as a foundation for the development of effective T-cell-based vaccines or immunotherapies targeting HRV.

Conclusions: Here, we present an ethically approved study protocol for an observational and exploratory study investigating a novel epitope-based vaccine targeting HRV, with a focus on pediatric asthma and adult COPD cohort populations.

International registered report identifier (irrid): DERR1-10.2196/73383.

Keywords: COPD; asthma; chronic obstructive pulmonary disease rhinovirus; epitopes; exploratory; observational study.; protocol; study design; vaccine.

Figure 1

Human rhinovirus proteome and structure. (A) Capsid and nonstructural proteins. (B) Rhinovirus capsid Viral Proteins (VP) related to the site of attachment to cell surface receptors (VP1-3) and internal capsid protein (VP4). Figure created with Biorender. RDRP: RNA-dependent RNA polymerase.

Figure 2

Human rhinovirus entry into the respiratory epithelium. Schematic illustrating human rhinovirus serotypes A, B, and C and their respective viral entry receptors. HRV-A and B primarily bind to the ICAM-1 (CD54) or LDL receptor, whereas HRV-C typically targets the CDHR3 receptor. Upon endosomal entry, TLR receptors 7 and 8 recognize the virus, triggering the release of IFN-γ and pro-inflammatory cytokines. Figure created with Biorender. CD54: cluster of differentiation 54; CDH3: Cadherin-Related Family Member 3; HRV: human rhinoviruses; ICAM-1: intercellular adhesion molecule 1; LDL: low-density lipoprotein; TLR: toll-like receptor.

Figure 3

Human rhinovirus epitope selection and analysis overview. (A) Computer-aided selection of epitopes. HRV sequence variability was evaluated via Shannon entropy, and peptides were selected based on HLA-I and HLA-II binding affinity using RANKPEP. Epitope peptides were synthesized and validated experimentally. (B) Study design and participant recruitment. Pediatric and adult patients were selected according to predefined inclusion and exclusion criteria. (C) T-cell–specific immune responses will be assessed in vitro through stimulation with epitope pools, followed by flow cytometry and Luminex assays. (D) Transcriptional analysis of blood samples (both unstimulated PBMCs and following epitope stimulation, PBMCs) will be conducted to identify gene expression profiles associated with epitope protective immunity. Figure created with Biorender. BDR: bronchodilator response; CD4: cluster of differentiation 4; CD8: cluster of differentiation 8; CDHR3: cadherin-related family member 3; COPD: chronic obstructive pulmonary disease; FeNO: fractional exhaled nitric oxide; FEV: forced expiratory volume; FEV/FVC: ratio of forced expiratory volume in 1 second to forced vital capacity; FVC: forced vital capacity; HLA: human leukocyte antigen; HRV: human rhinovirus; ICAM-1: intercellular adhesion molecule 1; LDL receptor: low-density lipoprotein receptor; PBMC: peripheral blood mononuclear cells; PFV: peak flow variability.