Study of viral pathogenesis in humanized mice

•Many human pathogens have a narrow host range.•Engraftment of human tissues into mice can render animals susceptible to infection.•Genetic humanization has yielded mice with inheritable susceptible to viral infection.•Additional refinements are needed to improve the utility of humanized mice.

Many of the viral pathogens that cause infectious diseases in humans have a highly restricted species tropism, making the study of their pathogenesis and the development of clinical therapies difficult. The improvement of humanized mouse models over the past 30 years has greatly facilitated researchers' abilities to study host responses to viral infections in a cost effective and ethical manner. From HIV to hepatotropic viruses to Middle East Respiratory Syndrome coronavirus, humanized mice have led to the identification of factors crucial to the viral life cycle, served as an outlet for testing candidate therapies, and improved our abilities to analyze human immune responses to infection. In tackling both new and old viruses as they emerge, humanized mice will continue to be an indispensable tool.