Pathogens and hosts require rapid modulation of virulence and defense mechanisms at the infection axis, but monitoring such modulations is challenging. In studying the human fungal pathogen Cryptococcus neoformans , mouse and rabbit infection models are often employed to shed light on the disease mechanisms but that may not be clinically relevant. In this study, we developed an animal infection model using the non-human primate cynomolgus monkey Macaca fascicularis . In addition, we systematically profiled and compared transcriptional responses between the infected mice and the cynomolgus monkey, using simultaneous or dual RNA next-generation sequencing. We demonstrated that there are shared but distinct transcriptional profiles between the two models following C . neoformans infection. Specifically, genes involved in immune and inflammatory responses are all upregulated. Osteoclastogenesis and insulin signaling are also significantly co-regulated in both models and disrupting an osteoclastogenesis-associated gene (OC-STAMP) or the insulin-signaling process significantly altered the host tolerance to C . neoformans . Moreover, C . neoformans was shown to activate metal sequestration, dampen the sugar metabolism, and control cell morphology during infection. Taking together, we described the development of a non-human primate model of cryptococcosis that allowed us to perform an in-depth analysis and comparison of transcriptome profiles during infections of two animal models and conceptually identify host genes important in disease responses. This study provides new insights in understanding fungal pathogenesis mechanisms that potentially facilitate the identification of novel drug targets for the treatment of cryptococcal infection.

Lysine acetylation is critical in regulating important biological processes in many organisms, yet little is known about acetylome evolution and its contribution to phenotypic diversity. Here, we compare the acetylomes of baker’s yeast and the three deadliest human fungal pathogens, Cryptococcus neoformans , Candida albicans , and Aspergillus fumigatus . Using mass spectrometry enriched for acetylated peptides together with public data from Saccharomyces cerevisiae , we show that fungal acetylomes are characterized by dramatic evolutionary dynamics and limited conservation in core biological processes. Notably, the levels of protein acetylation in pathogenic fungi correlate with their pathogenicity. Using gene knockouts and pathogenicity assays in mice, we identify deacetylases with critical roles in virulence and protein translation elongation. Finally, through mutational analysis of deactylation motifs we find evidence of positive selection at specific acetylation motifs in fungal pathogens. These results shed new light on the pathogenicity regulation mechanisms underlying the evolution of fungal acetylomes.

Cryptococcus neoformans is a causative agent for pulmonary infection and meningoencephalitis. Understanding the host's response to C. neoformans infection is critical for developing effective treatment. Even though some have elucidated the host response at the transcriptome level, little is known about how it modulates its defense machinery through the proteome mechanism or how protein posttranslational modification responds to the infection. In this work, we employed a murine infection model and mass spectrometry to systematically determine the proteome and acetylome statuses of lungs and brains in the early stage of infection. To extensively analyze the host response, we integrated the proteome data to the transcriptome results. Critical genes, including genes involved in phagosome, lysosome, and platelet activation are significantly altered in protein and gene expression during infection. In the acetylome analysis, we demonstrated that lung and brain tissues differentially regulate protein acetylation during infection. The three primary groups of proteins altered in acetylation status are histones, proteins involved in glucose and fatty acid metabolism, and proteins from the immune system. These analyses provide an integrative regulation network of the host responding to C. neoformans and shed new light on understanding the host's regulation mechanism when responding to C. neoformans.

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