Hyper-antigenic variation occurs with human rhinovirus type 17

Area of Science:

• Virology
• Immunology
• Molecular Biology

Background:

• Human rhinoviruses (RVs) exhibit diverse serotypes, with 50 of 90 classified into 16 antigenic groups.
• Antigenic variation in RVs is hypothesized to arise due to immunologic pressure.
• Understanding RV antigenic drift is crucial for vaccine development and disease control.

Purpose of the Study:

• To investigate the potential for selecting antigenic variants of human rhinoviruses (RVs) under laboratory conditions mimicking immunologic pressure.
• To determine if specific RV serotypes are more prone to generating antigenic variants.
• To characterize the antigenic properties of selected RV variants.

Main Methods:

• Cloning of 16 plaque-purified RV serotypes in the presence of homologous, polyclonal antisera.
• Examination of cloned isolates for antigenic variation using serum cross-neutralization tests with parental and isolate-specific antisera.
• Characterization of variants as prime strains using specific antisera.

Main Results:

• Only human rhinovirus type 17 (RV-17) yielded significant antigenic variants after cloning under selective pressure.
• Some RV-17 variants exhibited up to a 500-fold difference in neutralizing antibody titers compared to the parental strain.
• Further immunoselection of RV-17 variants generated additional variants, some of which no longer met the classification criteria for RV-17.

Conclusions:

• Human rhinovirus type 17 is capable of generating major antigenic variants when subjected to immunologic pressure.
• The study provides experimental evidence supporting the hypothesis that immunologic pressure can drive RV antigenic variation.
• The emergence of novel antigenic variants highlights challenges in maintaining effective immunity against evolving rhinovirus populations.