Biology subjects

Cook, P. C.

Publications and source records attributed to Cook, P. C..

3 recordsLinked to original sources

bioRxiv2025

Hallmarks and metabolic regulation of type 2 activated human lung macrophages

Although human lung macrophages are heterogenous and play key roles during health and disease, the mechanisms that govern their activation and function are unclear, particularly in type 2 settings. Our understanding of how human lung macrophages respond to inflammatory signals have predominantly relied on cell lines or peripheral blood derived cells, which have a limited capacity to reflect the complexity of tissue macrophage responses. Therefore, we isolated macrophages from resected human lung tissue and stimulated them ex vivo under type 2 (IL-4, IL-13, or IL-4 + IL-13) or type 1 (IFN{gamma} + LPS) conditions. Human lung macrophages stimulated with IL-4/13, alone or in combination, significantly upregulated expression of the chemokines CCL17, CCL18 and CCL22, along with the transglutaminase TGM2 and the lipoxygenase ALOX15. This type 2 activation profile was distinct from LPS + IFN{gamma} activated human lung macrophages, which upregulated IL6, IL8, IL1{beta}, TNF and CHI3L1 (YKL-40). Further, type 2 activated human lung macrophage products showed differential metabolic reliance for their induction, with IL-4/13 induced CCL22 being glycolytically controlled, while ALOX15 was regulated by fatty acid oxidation. These data clarify hallmarks of human lung macrophage activation and polarisation in addition to revealing novel metabolic regulation of type 2 markers.

immunology↗

bioRxiv2024

Aspergillus-mediated allergic airway inflammation is triggered by dendritic cell recognition of a defined spore morphotype, a process that can be targeted via antifungal therapeutics.

BackgroundExposure to fungi, especially Aspergillus fumigatus (A.f.), can elicit potent allergic inflammation that triggers and worsens asthmatic disease. Dendritic cells (DCs), initiate allergic inflammatory responses to allergic stimuli. However, it is unclear if A.f. spores during isotropic growth (early spore swelling) can activate DCs to initiate allergic responses or if germination is required. This lack of basic understanding of how A.f. causes disease is a barrier to the development of new treatments. ObjectiveTo show that a precise A.f. morphotype stage during spore swelling can trigger DCs to mediate allergic inflammatory responses and ascertain if antifungal therapeutics can be effective at suppressing this process. MethodsWe employed an A.f. strain deficient in pyrimidine biosynthesis ({Delta}pyrG) to generate populations of A.f. spores arrested at different stages of isotropic growth (swelling) via temporal removal of uracil and uridine from growth media. These arrested spore stages were cultured with bone marrow derived DCs (BMDCs), and their activation measured via flow cytometry and ELISA to interrogate which growth stage was able to activate BMDCs. These BMDCs were then adoptively transferred into the airways, to assess if they were able to mediate allergic inflammation in naive recipient mice. Allergic airway inflammation in vivo was determined via flow cytometry, ELISA and qPCR. This system was also used to determine if antifungal drug (itraconazole) treatment could alter early stages of spore swelling and therefore BMDC activation and in vivo allergic inflammation upon adoptive transfer. ResultsWe found that A.f. isotropic growth is essential to trigger BMDC activation and mediate allergic airway inflammation. Furthermore, using time arrested A.f. stages, we found that least 3h in growth media enabled spores to swell sufficiently to activate BMDCs to elicit allergic airway inflammation in vivo. Incubation of germinating A.f. with itraconazole reduced spore swelling and partially reduced their ability to activate BMDCs to elicit in vivo allergic airway inflammation. ConclusionIn summary, our results have pinpointed the precise stage of A.f. development when germinating spores are able to activate DCs to mediate downstream allergic airway inflammation. Furthermore, we have identified that antifungal therapeutics can be effective in reducing the potential of A.f. spores to stimulate allergic responses, highlighting a potential mechanism by which antifungal treatment might help to prevent the development of fungal allergy.

immunology↗

bioRxiv2023

Mgl2+ cDC2s coordinate fungal allergic airway type 2, but not type 17, inflammation.

Fungal spores are abundant in the environment and a major cause of asthma. Originally characterised as a type 2 inflammatory disease, allergic airway inflammation that underpins asthma can also involve type 17 inflammation, which can exacerbate disease causing failure of treatments tailored to inhibit type 2 factors. However, the mechanisms that determine the host response to fungi, which can trigger both type 2 and type 17 inflammation in allergic airway disease, remain unclear. We found that CD11c+ DCs and CD4+ T cells are essential for development of both type 2 and type 17 airway inflammation in mice when repeatedly exposed to inhaled spores. Single cell RNA-sequencing enabled the development of multi-parameter cytometry that identified allergic inflammation dramatically altered the proportion of numerous DC clusters in the lung, but that only two of these (Mgl2+ cDC2s and CCR7+ DCs) migrated to the dLNs. Targeted removal of several DC subsets revealed that only Mgl2+ cDC2 depletion dramatically reduced type 2, but not type 17, anti-fungal allergic airway inflammation. These data highlight distinct DC subsets are potential therapeutic targets for the treatment of pulmonary fungal disease.

immunology↗