In this work, a general methodology for the longitudinal evaluation of lung pathology in mouse models of aspergillosis and cryptococcosis, respiratory fungal infections, utilizing low-dose high-resolution computed tomography, is detailed.

Aspergillus fumigatus and Cryptococcus neoformans infections represent significant and life-threatening fungal hazards for immunocompromised individuals. Seladelpar ic50 Patients with acute invasive pulmonary aspergillosis (IPA) and meningeal cryptococcosis experience the most severe outcomes, marked by elevated mortality rates, despite the application of current treatments. To gain a more comprehensive grasp of these fungal infections, additional research is paramount, extending beyond clinical observations to encompass controlled preclinical experimental settings. Understanding their virulence, interactions with the host, infection progression, and effective treatment strategies are key goals. The use of preclinical animal models provides a pathway to greater comprehension of particular needs. However, the quantification of disease severity and fungal load in mouse models of infection frequently suffers from the use of less sensitive, single-time, invasive, and variable methodologies, such as colony-forming unit determination. These issues are surmountable through the use of in vivo bioluminescence imaging (BLI). Dynamic, visual, and quantitative longitudinal information on fungal burden, provided by BLI (a noninvasive tool), is crucial for understanding infection onset, potential dissemination throughout different organs, and the entire disease progression in individual animals. This paper outlines a complete experimental procedure, from mouse infection to BLI data acquisition and analysis, facilitating non-invasive, longitudinal monitoring of fungal load and dissemination during infection development. This methodology is ideal for preclinical research on IPA and cryptococcal disease pathophysiology and treatment.

The elucidation of fungal infection pathogenesis and the development of novel therapeutics have been significantly advanced by the utilization of animal models. Mucormycosis, while not common, frequently results in either fatality or significant debilitation. Various species of fungi cause mucormycoses, with infection routes and patient risk factors differing significantly. Subsequently, diverse types of immunosuppression and routes of infection are employed in relevant animal models for clinical use. It elaborates upon the intranasal application methods for the purpose of creating pulmonary infections, in addition. Ultimately, a discussion follows regarding specific clinical parameters suitable for constructing scoring systems and establishing humane endpoints within murine models.

Pneumonia, a consequence of Pneumocystis jirovecii infection, primarily affects individuals with impaired immunity. The analysis of host-pathogen interactions, along with drug susceptibility testing, faces a considerable hurdle in the form of Pneumocystis spp. Viable in vitro growth is not possible for these. Cultivating the organism continuously is presently unavailable, thus hindering the identification of new drug targets. The constrained nature of the system has made mouse models of Pneumocystis pneumonia incredibly valuable to researchers. Seladelpar ic50 The chapter provides a synopsis of selected methodologies utilized in murine infection models. These include in vivo Pneumocystis murina propagation, transmission routes, available genetic mouse models, a model specifically targeting P. murina life forms, a mouse model designed for PCP immune reconstitution inflammatory syndrome (IRIS), and the associated experimental parameters involved.

The worldwide emergence of dematiaceous fungal infections, particularly phaeohyphomycosis, is marked by their varied clinical presentations. The mouse model serves as a valuable tool for mimicking dematiaceous fungal infections in humans, a process mirroring phaeohyphomycosis. Our laboratory successfully created a mouse model of subcutaneous phaeohyphomycosis, uncovering marked phenotypic differences between Card9 knockout and wild-type mice. These differences mirror the increased vulnerability to infection observed in CARD9-deficient humans. The construction of a mouse model exhibiting subcutaneous phaeohyphomycosis, and the subsequent experiments, are presented here. We believe this chapter will be profoundly useful in the study of phaeohyphomycosis, driving the development of superior diagnostic and therapeutic procedures.

Indigenous to the southwestern United States, Mexico, and portions of Central and South America, the fungal disease coccidioidomycosis is caused by the dimorphic pathogens Coccidioides posadasii and C. immitis. In research concerning disease pathology and immunology, the mouse is the primary experimental subject. Coccidioides spp. poses a significant vulnerability to mice, hindering research on the adaptive immune responses crucial for controlling coccidioidomycosis. The following describes the procedure to infect mice, creating a model for asymptomatic infection with controlled chronic granulomas and a slow, yet ultimately fatal, progression. The model replicates human disease kinetics.

Experimental rodent models provide a practical approach to elucidating the dynamic relationship between host and fungus in fungal diseases. Spontaneous cures in animal models used for studying Fonsecaea sp., a causative agent of chromoblastomycosis, complicate the creation of a disease model mirroring the prolonged chronic disease in humans. In this chapter, a rodent model, employing subcutaneous administration, was detailed. The model exhibited acute and chronic lesion characteristics analogous to human conditions. Analysis encompassed fungal load and lymphocyte counts.

Commensal organisms, numbering in the trillions, constitute a significant part of the human gastrointestinal (GI) tract's microbial ecosystem. Certain microbes possess the potential to transform into pathogens as a consequence of alterations within the surrounding environment and/or the host's physiological state. In most people, Candida albicans resides as a harmless commensal in the gastrointestinal tract, but it has the potential to trigger a severe infection. Gastrointestinal infections by Candida albicans can be influenced by factors such as antibiotic use, neutropenia, and abdominal surgical procedures. A crucial focus of research is to uncover how beneficial commensal organisms can transform into dangerous pathogens. The study of Candida albicans's transition from a benign commensal to a pathogenic fungus is critically facilitated by mouse models of fungal gastrointestinal colonization. This chapter explores a groundbreaking approach to the consistent, long-term colonization of the murine gastrointestinal system by the Candida albicans fungus.

Invasive fungal infections are capable of leading to fatal meningitis, frequently affecting the brain and central nervous system (CNS) in compromised immune systems. Recent technological breakthroughs have facilitated a shift in focus from examining the brain's inner tissue to comprehending the immunological processes within the meninges, the protective sheath encompassing the brain and spinal cord. Advanced microscopy techniques have enabled researchers to begin visualizing both the anatomical structure of the meninges and the cellular components responsible for meningeal inflammation. Imaging meningeal tissue by confocal microscopy relies on the mounting techniques described within this chapter.

The long-term control and elimination of fungal infections in humans, particularly those caused by Cryptococcus, are contingent upon the function of CD4 T-cells. A crucial step in understanding the intricate mechanisms of fungal infection pathogenesis lies in elucidating the workings of protective T-cell immunity. We detail a protocol for in vivo examination of fungal-specific CD4 T-cell responses, achieved via adoptive transfer of fungal-specific T-cell receptor (TCR) transgenic CD4 T-cells. This protocol, while utilizing a TCR transgenic model responsive to Cryptococcus neoformans peptides, holds adaptable potential for other fungal infection research settings.

The opportunistic fungal pathogen, Cryptococcus neoformans, presents a significant threat by frequently causing fatal meningoencephalitis in patients whose immune systems are impaired. This fungus, thriving within the host's cells, eludes the host immune system, leading to a latent infection (latent cryptococcal neoformans infection, LCNI), and its reactivation, occurring when the host immune system is suppressed, causes cryptococcal disease. Understanding the underlying pathophysiology of LCNI is hampered by the limited availability of mouse models. This report details the currently established methods for LCNI and the methods for reactivation.

The fungal pathogen, Cryptococcus neoformans species complex, causes cryptococcal meningoencephalitis (CM), which can have a high mortality rate or lead to debilitating neurological sequelae in those who survive, often due to excessive inflammation in the central nervous system (CNS). This is particularly true for those who develop immune reconstitution inflammatory syndrome (IRIS) or post-infectious immune response syndrome (PIIRS). Seladelpar ic50 Human studies face limitations in determining the cause-and-effect relationship of specific pathogenic immune pathways during central nervous system (CNS) conditions; however, the use of mouse models enables examination of potential mechanistic connections within the CNS's immunological network. These models are especially beneficial for differentiating pathways primarily associated with immunopathology from those necessary for fungal defense. This protocol details methods for establishing a robust, physiologically relevant murine model of *C. neoformans* CNS infection, mirroring multiple aspects of human cryptococcal disease immunopathology and subsequent immunological analysis in detail. Employing tools such as gene knockout mice, antibody blockade, cell adoptive transfer, and high-throughput techniques like single-cell RNA sequencing, studies utilizing this model will yield novel insights into the cellular and molecular mechanisms underlying the pathogenesis of cryptococcal central nervous system diseases, paving the way for more efficacious therapeutic approaches.