Lung dendritic cells (DC) are powerful antigen-presenting cells constituted by various subpopulations that differ in terms of their function and origin and differentially regulate cell-mediated antifungal immunity. The lung is the primary target organ of Cryptococcus neoformans and C. gattii infections, which makes it essential in the establishment of the first line of anti-cryptococcal defense. However, the lung-specific dynamics and function of DC subsets are poorly understood in cryptococcosis. In this study, we provide evidence for the in vivo function of a conventional langerin-expressing DC1 dendritic cell (LangDC1) population during the first week of intratracheal C. neoformans infection in mice. By using conditional depletion of LangDC1 after diphtheria toxin treatment of LangDTREGFP mice, we demonstrate that these animals better control the fungal infection and produce type 1 and 17 cytokines in the context of a type 2 immune response, favoring a predominance of iNOS over arginase-1 expression by pulmonary cells. Our results suggest that LangDC1 cells play a role in impairing immune response for the clearance of C. neoformans in the early stage of pulmonary infection.
23 December 2024 in Journal of Investigative Dermatology
Intestinal dysbiosis is common in people living with HIV/AIDS (PLWH), yet fungal communities of the gut microbiota (mycobiota) remain poorly characterized, especially in severely immunosuppressed patients. We analyzed the gut mycobiota of 33 PLWH and 20 healthy controls from a public hospital in central Argentina. Most PLWH presented severe immunosuppression (<200 CD4+ T cells/μL) and acute or chronic diarrhea, with or without antibiotic exposure or antiretroviral therapy. Fecal DNA was extracted and the ITS2 region was sequenced using next-generation sequencing. Beta-diversity analyses revealed significant segregation between PLWH and controls (PERMANOVA, Adonis: p = 0.001, R² = 0.0989). LEfSe analysis identified 17 fungal species enriched in PLWH, predominantly Candida albicans, Candida dubliniensis, and Nakaseomyces glabratus, whereas 31 species were more abundant in controls, including Penicillium spp., Candida sake, and Clavispora lusitaniae. Histoplasma capsulatum, an endemic pathogen in the region, was more prevalent in PLWH and associated with CD4+T-cell counts. Dirichlet multinomial mixture analysis revealed two mycobiotypes: M1, with a balanced fungal composition predominating in controls, and M2, dominated by Candida species and present in PLWH. These findings provide novel insights into gut mycobiota alterations in severely immunosuppressed PLWH in Argentina, highlighting Candida-driven dysbiosis and the regional relevance of H. capsulatum.
Intestinal dysbiosis is common in people living with HIV/AIDS (PLWH), yet fungal communities of the gut microbiota (mycobiota) remain poorly characterized, especially in severely immunosuppressed patients. We analyzed the gut mycobiota of 33 PLWH and 20 healthy controls from a public hospital in central Argentina. Most PLWH presented with severe immunosuppression (<200 CD4+ T cells/μL) and acute or chronic diarrhea, with or without antibiotic exposure or antiretroviral therapy. Fecal DNA was extracted and the ITS2 region was sequenced using next-generation sequencing. Beta-diversity analyses revealed significant segregation between PLWH and controls (PERMANOVA, Adonis: p = 0.001, R2 = 0.0989). LEfSe analysis identified 17 fungal species enriched in PLWH, predominantly Candida albicans, Candida dubliniensis, and Nakaseomyces glabratus, whereas 31 species were differentially represented in controls, including Penicillium spp., Candida sake, and Clavispora lusitaniae. Histoplasma capsulatum, an endemic pathogen in the region, was more prevalent in PLWH and associated with low CD4+ T cell counts. Dirichlet multinomial mixture analysis revealed two mycobiotypes: M1, with a balanced fungal composition predominating in controls, and M2, dominated by Candida species and present in PLWH. These findings provide novel insights into gut mycobiota alterations in severely immunosuppressed PLWH in Argentina, highlighting Candida-driven dysbiosis and the regional relevance of H. capsulatum.