Cutting Edge: IL-17–Secreting Innate Lymphoid Cells Are Essential for Host Defense against Fungal Infection

Abstract

Soil microbiome modification may alter system function, which may enhance processes like bioremediation. In this study, we filled microcosms with gamma-irradiated soil that was reinoculated with the initial soil or cultivated bacterial subsets obtained on regular media (REG-M) or media containing crude oil (CO-M). We allowed 8 weeks for microbiome stabilization, added crude oil and monoammonium phosphate, incubated the microcosms for another 6 weeks, and then measured the biodegradation of crude oil components, bacterial taxonomy, and functional gene composition. We hypothesized that the biodegradation of targeted crude oil components would be enhanced by limiting the microbial taxa competing for resources and by specifically selecting bacteria involved in crude oil biodegradation (i.e., CO-M). Postincubation, large differences in taxonomy and functional gene composition between the three microbiome types remained, indicating that purposeful soil microbiome structuring is feasible. Although phylum-level bacterial taxonomy was constrained, operational taxonomic unit composition varied between microbiome types. Contrary to our hypothesis, the biodegradation of C 10 to C 50 hydrocarbons was highest when the original microbiome was reinoculated, despite a higher relative abundance of alkane hydroxylase genes in the CO-M microbiomes and of carbon-processing genes in the REG-M microbiomes. Despite increases in the relative abundances of genes potentially linked to hydrocarbon processing in cultivated subsets of the microbiome, reinoculation of the initial microbiome led to maximum biodegradation. IMPORTANCEIn this study, we show that it is possible to sustainably modify microbial assemblages in soil. This has implications for biotechnology, as modification of gut microbial assemblages has led to improved treatments for diseases like Clostridium difficile infection. Although the soil environment determined which major phylogenetic groups of bacteria would dominate the assemblage, we saw differences at lower levels of taxonomy and in functional gene composition (e.g., genes related to hydrocarbon degradation). Further studies are needed to determine the success of such an approach in nonsterile environments. Although the biodegradation of certain crude oil fractions was still the highest when we inoculated with the diverse initial microbiome, the possibility of discovering and establishing microbiomes that are more efficient in crude oil degradation is not precluded.O il production, oil spills, and the storage of oily wastes by the petroleum industry have led to massive releases of petroleum hydrocarbons into the environment, making them some of the most ubiquitous environmental pollutants (1). Conventional decontamination technologies such as excavation (i.e., dig and dump), incineration, and chemical treatment of contaminants are costly and may further disrupt disturbed ecosystems (2, 3). When effective, bioremediation is a cheaper and more sustainable approach to decontamination. Bioaugmentation, the addition...

IL-1 signaling inhibits Trichophyton rubrum conidia development and modulates the IL-17 response in vivo

“…34 IL-17-producing ILCs were also reported to determine protection against C. albicans in a murine model of oropharyngeal candidiasis. 33 Even neutrophils can be a source of IL-17, 35 and their importance in a model of keratitis by Aspergillus was also documented. 36 In conclusion, our findings add T.rubrum as another NLRP3 inflammasome activator, supporting this system as another component of the inflammatory process in dermatophytosis.…”

“…One example is the innate-like lymphoid cells (ILCs), a recently identified lymphoid lineage population whose functions show innate immunity-like features, as a fast-response timing. 32,33 Kim et.al. showed that obesity-associated airway hyperactivity is driven by ILCs-derived IL-17 and the recruitment of these Figure 6.…”

Type 3 innate lymphoid cell depletion is mediated by TLRs in lymphoid tissues of simian immunodeficiency virus‐infected macaques

“…The loss of T h 17 and T h 22 cells has been correlated with the breakdown of mucosal integrity, microbial translocation, and chronic immune activation (22,40,41). Because ILC3 cells play critical roles in formation of lymphoid tissue, adaptive immunity, regulation of mucosal microbiota via AhR, restoration of secondary lymphoid tissues after injury, and maintenance of intestinal memory CD4 T cells (3,17,18,45), their losses undoubtedly contribute to compromised mucosal immunity in HIV infection and AIDS, including failure of humoral immune responses.…”

“…These ILC3 cells highly expressed CD90 (∼63%) and aryl hydrocarbon receptor and produced IL-17 (∼63%), IL-22 (∼36%), and TNF-a (∼72%) but did not coexpress CD4 or NK cell markers. The intestinal ILC3 cell loss correlated with the reduction of total CD4 + T cells and T helper (T h ) 17 and Th22 cells in the gut during SIV infection (P < 0.001). Notably, ILC3 could be induced to undergo apoptosis by microbial products through the TLR2 (lipoteichoic acid) and/or TLR4 (LPS) pathway.…”

“…ILC2 cells produce T h 2 cytokines IL-5 and IL-13, express the transcriptional factor guanine adenine thymine adenine sequence-binding protein 3, and play important roles in immunity to helminth infections and in the pathogenesis of allergic reactions such as asthma (14)(15)(16). ILC3 cells are an important source of the T h 17 cytokines IL-17A and IL-22 and express the retinoic acid receptor-related orphan receptor g. ILC3 cells are implicated in mucosal immunity to extracellular bacteria, regulation of adaptive immune cell homeostasis, maintenance of intestinal memory CD4 + T cells, providing help to marginal zone B cells, and in the organogenesis and maintenance of secondary lymphoid tissues (7,(17)(18)(19)(20).…”