High resolution mapping of human rhinovirus-specific antibody responses

Rhinovirus (RV) infections are not only a major cause of the common cold but are also major triggers of acute exacerbations of asthma and chronic obstructive pulmonary disease (COPD) in both children and adults. The association of rhinovirus infections with exacerbations of respiratory disease is mainly based on the demonstration of virus at the onset of exacerbation but there are currently no serological tests for the diagnosis of a RV infection which would show an immune response. Within this project a high resolution antibody assay based on peptides and recombinant antigens from the most common RV strains will be established to identify antibody signatures which discriminate RV species- and phylogenetically related RV types in RV-infected patients1 using multiplex (i.e., micro-arrays) immune assays. The RV micro-array will allow to identify the most common and important rhinovirus strains involved in the exacerbation of severe respiratory disease such as asthma and chronic obstructive pulmonary disease (COPD) in population studies and different ages (children, adults). Furthermore micro-array testing should allow to identify antibody signatures which protect against RV infections. The project should therefore contribute to the identification of the most relevant and clinically important RV strains involved in triggering exacerbations of respiratory diseases and form a basis for the rational development of novel vaccines for preventing rhinovirus infections and associated respiratory diseases. 1 Following reviewers suggestion, the term strain-specific has been replaced by the term specific for RV species and phylogenetically related RV types.

Rhinovirus (RV) infections are major triggers of acute exacerbations of asthma and chronic obstructive pulmonary disease (COPD) leading very often to hospitalization and death. The association of RV infections with exacerbations of respiratory diseases has been mainly based on the demonstration of the virus at the onset of exacerbation but no serological tests have been available which would allow detecting different specificities of antibody responses against RV epitopes. Therefore, in the course of this research project antibody assays (i.e., ELISA and high-resolution microarrays) based on recombinant RV capsid proteins, recombinant VP1 fragments and synthetic peptides representing three RV genetic species (i.e., RV-A, RV-B and RV-C) were developed and used to analyze in detail RV-specific immune responses in serum samples of infected individuals. First of all, it could be demonstrated that it is indeed possible to identify culprit RV species in patients with virus-induced exacerbations of respiratory diseases by measuring strain-specific increases of antibodies with only few microliter of serum. Furthermore, one could not only identify the culprit virus species having caused the respiratory attacks but the data also indicated that certain RV species were especially dangerous. In addition, the contribution of allergen exposure and RV infections as possible trigger factors for acute wheezing attacks in a cohort of preschool children was investigated. Accordingly, the use of such micro-arrayed biomarkers for the differential diagnosis of respiratory disease exacerbations triggered by allergen exposure in a sensitized subject and/or by RV infections has been proposed in order to initiate personalized forms of asthma treatment based on the identification of the asthma trigger factors. Finally, an ELISA-based interaction assay using purified rhinovirus strains and the corresponding human receptor proteins for studying the interaction of the major and minor group RVs, including RV-A and RV-B species, was established and characterized in the course of this project. This assay should be useful for the preclinical evaluation of preventive and therapeutic strategies targeting the RV-receptor interaction, such as vaccines, antibodies, and anti-viral compounds in order to pave the way towards RV-specific therapeutic and preventive strategies.