Targeting host cofactors to inhibit viral infection

The majority of FDA-approved drugs indicated for the treatment of viral infections are inhibitors of viral proteins, of which the emergence of resistant strains is a major concern. This issue is exacerbated as most developed antiviral therapies are indicated for the treatment of viruses with error-prone replication. These problems may be addressed by the development of drugs that modulate the function of host factors involved in various aspects of a viral life cycle. Targeting host factors uncouples the mutation of a druggable protein gene from the replication and survival selection pressure exerted on a virus. Currently, a host-targeting antiviral （HTA）, maraviroc, is approved for the treatment of human immunodeficiency virus （HIV） infection. In addition, several HTAs indicated for the treatment of hepatitis C virus （HCV） or HIV infection are at various stages of clinical evaluation. Targeting host factors is an attractive complement to therapies directly targeting a viral protein because of the expected higher genetic barrier for resistance and an overall increase in the diversity of treatment options. We examine how the integrated roles of emerging host cofactor screening approaches and drug development strategies may advance current treatment options.