Gisa Gerold is a researcher at the Institute of Virology, Medical University of Innsbruck in Austria. Dr. Gerold's research integrates mass spectrometry-based proteomics and CRISPR-based gene editing to identify and characterize host factors, such as human CD81, that are essential for the replication of arthritogenic alphaviruses like Chikungunya virus (CHIKV).
Virus emergence poses an increasing challenge to human health. In particular, mosquito-borne viruses are causing outbreaks in new geographic areas as virus-transmitting mosquito species become endemic in these regions. Chikungunya virus (CHIKV) is one such a re-emerging virus, responsible for more than 300,000 reported infections worldwide between January and August 2025. CHIKV can cause debilitating arthritis-like symptoms that may persist for several months. To date, no specific treatments are available to combat Chikungunya disease. Developing effective intervention strategies requires a thorough understanding of virus-host interactions. CHIKV and related alphaviruses replicate in plasma membrane-derived compartments known as "spherules”. Through our work, which integrates mass spectrometry-based proteomics and CRISPR-based gene editing, we identified human CD81 as replication factor for CHIKV. We investigated the specific viral life cycle step supported by CD81, identified CD81 interaction partners as additional virus host factors, and proposed a model in which CD81 supports alphavirus replication by stabilizing membrane curvature. Notably, the cholesterol-binding residues of CD81 are essential for supporting alphavirus replication. Identification of central molecular networks used by viruses holds the promise of successful development of pandemic preparedness strategies.