The term, microbiome, describes the collective microbes that inhibit our bodies and other environments. In the Yin Lab we focus on a subset of the microbiome, the virome, or collective viruses associated with humans and their environments. Some viruses might be beneficial; for example, viruses that infect pathogenic microbes may contribute to a microbiome that promotes our health. Other viruses, especially the ones that make us sick, are well known, for example, HIV-1, hepatitis, ebola, the common cold, zika, and influenza. More recently, the COVID-19 pandemic was caused by the severe acute respiratory syndrome coronavirus 2, known as SARS-CoV-2.
Many viruses, including coronaviruses, make errors when they reproduce by introducing mutations in their genomes. Such mutations can expand their powers, enabling them to infect new host species, like jumping from bats to humans. Or the mutant viruses can evade host immune responses and escape drug treatments. More broadly, the mutations can lead to diseases that persist or re-emerge.
Alternatively, extreme errors can delete key virus functions, rendering the virus non-infectious. Such ‘dead’ viruses are ubiquitous byproducts of virus infections in humans and in natural host reservoirs. Remarkably, such dead viruses can spring to life if they invade a productively infected host cell, where they can reproduce at the expense of the normal virus. These molecular parasites of normal virus growth have potential as therapeutics. It is currently unknown to what extent such defective viruses might stimulate host immune responses in ways that might be protective versus causing more severe disease. In the Yin Lab we are working to understand how such defective viruses can impact disease severity and how they might be engineered to prevent future pandemics.