Immunological Analysis of Cryptococcal Meningoencephalitis in a Murine Model

Cryptococcal meningoencephalitis (CM), caused by the fungal pathogen Cryptococcus neoformans species complex, can lead to high mortality or severe neurological sequelae in survivors that are associated with excessive inflammation in the central nervous system (CNS), especially in those who develop immune reconstitution inflammatory syndrome (IRIS) or postinfectious immune response syndrome (PIIRS). While the means to establish a cause-and-effect relationship of a specific pathogenic immune pathway during CM by human studies are limited, mouse models allow dissection of the potential mechanistic links within the CNS immunological network. In particular, these models are useful for separating pathways contributing predominantly to immunopathology from those important for fungal clearance. In this protocol, we described methods to induce a robust, physiologically relevant murine model of C. neoformans CNS infection that reproduces multiple aspects of human cryptococcal disease immunopathology and subsequent detailed immunological analysis. Combined with tools including gene knockout mice, antibody blockade, cell adoptive transfer, as well as high throughput techniques such as single-cell RNA sequencing, studies using this model will provide new insights regarding the cellular and molecular processes that elucidate the pathogenesis of cryptococcal CNS diseases in order to develop more effective therapeutic strategies.