Overview of vertebrate animal models of fungal infection

Usefulness of silkworm as a model animal for understanding the molecular mechanisms of fungal pathogenicity

Candida albicans, Candida tropicalis, Candida grabrata, and Cryptococcus neoformans are causative pathogens of opportunistic diseases in immunocompromised human patients. Silkworms are killed by injection of these pathogenic fungi into their hemolymph. In this paper, we describe recent results by our laboratory and other researchers using gene-deficient strains of these pathogenic fungi. The silkworm is considered to be a useful model animal for understanding the pathogenicity of these fungi. Silkworms are also beneficial for evaluating therapeutically active anti-fungal reagents.

Mouse ENU Mutagenesis to Understand Immunity to Infection: Methods, Selected Examples, and Perspectives

Infectious diseases are responsible for over 25% of deaths globally, but many more individuals are exposed to deadly pathogens. The outcome of infection results from a set of diverse factors including pathogen virulence factors, the environment, and the genetic make-up of the host. The completion of the human reference genome sequence in 2004 along with technological advances have tremendously accelerated and renovated the tools to study the genetic etiology of infectious diseases in humans and its best characterized mammalian model, the mouse. Advancements in mouse genomic resources have accelerated genome-wide functional approaches, such as gene-driven and phenotype-driven mutagenesis, bringing to the fore the use of mouse models that reproduce accurately many aspects of the pathogenesis of human infectious diseases. Treatment with the mutagen N-ethyl-N-nitrosourea (ENU) has become the most popular phenotype-driven approach. Our team and others have employed mouse ENU mutagenesis to identify host genes that directly impact susceptibility to pathogens of global significance. In this review, we first describe the strategies and tools used in mouse genetics to understand immunity to infection with special emphasis on chemical mutagenesis of the mouse germ-line together with current strategies to efficiently identify functional mutations using next generation sequencing. Then, we highlight illustrative examples of genes, proteins, and cellular signatures that have been revealed by ENU screens and have been shown to be involved in susceptibility or resistance to infectious diseases caused by parasites, bacteria, and viruses.