Blood vessel occlusion by Cryptococcus neoformans is a mechanism for haemorrhagic dissemination of infection.

Meningitis caused by infectious pathogens is associated with vessel damage and infarct formation, however the physiological cause is often unknown. Cryptococcus neoformans is a human fungal pathogen and causative agent of cryptococcal meningitis, where vascular events are observed in up to 30% of patients, predominantly in severe infection. Therefore, we aimed to investigate how infection may lead to vessel damage and associated pathogen dissemination using a zebrafish model that permitted noninvasive in vivo imaging. We find that cryptococcal cells become trapped within the vasculature (dependent on their size) and proliferate there resulting in vasodilation. Localised cryptococcal growth, originating from a small number of cryptococcal cells in the vasculature was associated with sites of dissemination and simultaneously with loss of blood vessel integrity. Using a cell-cell junction tension reporter we identified dissemination from intact blood vessels and where vessel rupture occurred. Finally, we manipulated blood vessel tension via cell junctions and found increased tension resulted in increased dissemination. Our data suggest that global vascular vasodilation occurs following infection, resulting in increased vessel tension which subsequently increases dissemination events, representing a positive feedback loop. Thus, we identify a mechanism for blood vessel damage during cryptococcal infection that may represent a cause of vascular damage and cortical infarction during cryptococcal meningitis.

What is the best simulation approach for measuring local density fluctuations near solvo-/hydrophobes?

Measurements of local density fluctuations are crucial to characterizing the interfacial properties of equilibrium fluids. A specific case that has been well-explored involves the heightened compressibility of water near hydrophobic entities. Commonly, a spatial profile of local fluctuation strength is constructed from the measurements of the mean and variance of solvent particle number fluctuations in a set of contiguous subvolumes of the system adjacent to the solvo-/hydrophobe. An alternative measure proposed by Evans and Stewart [J. Phys.: Condens. Matter 27, 194111 (2015)] defines a local compressibility profile in terms of the chemical potential derivative of the spatial number density profile. Using Grand canonical Monte Carlo simulation, we compare and contrast the efficacy of these two approaches for a Lennard-Jones solvent at spherical and planar solvophobic interfaces and SPC/E water at a hydrophobic spherical solute. Our principal findings are as follows: (i) the local compressibility profile χ(r) of Evans and Stewart is considerably more sensitive to variations in the strength of local density fluctuations than the spatial fluctuation profile F(r) and can resolve much more detailed structure; and (ii) while the local compressibility profile is essentially independent of the choice of spatial discretization used to construct the profile, the spatial fluctuation profile exhibits a strong systematic dependence on the size of the subvolumes on which the profile is defined. We clarify the origin and nature of this finite-size effect.

Patients undergoing multiligament knee reconstruction injured during pivoting sports demonstrate similar clinical, functional and return to sport outcomes by 2 years compared with those undergoing anterior cruciate ligament reconstruction.

PURPOSE: This study investigates the clinical and activity-based outcomes after anterior cruciate ligament reconstruction (ACLR) versus multiligamentous knee reconstruction (MLKR) following a pivoting sports injury. METHODS: Fifty MLKR patients were included, of which 20 (40%) were injured during pivoting sports. A further 50 patients undergoing ACLR following an injury during pivoting sports were consecutively recruited for comparison. Patients were assessed before the surgery and at 6-, 12- and 24 months with patient-reported outcome measures (PROMs) including the International Knee Documentation Committee (IKDC) form, Tegner activity scale (TAS) and anterior cruciate ligament return to sport after injury (ACL-RSI) score. Knee movement, the single (SHD) and triple (THD) hop tests for distance, and peak isokinetic knee extensor and flexor strength were assessed, with Limb Symmetry Indices (LSIs) calculated. Outcomes were compared across groups: (1) ACLR (n = 50), (2) MLKR (n = 50) and (3) MLKR due to pivoting sport injury (n = 20). RESULTS: IKDC, TAS and ACL-RSI scores remained lower (p < 0.05) in the full MLKR versus ACLR cohort at all timepoints. Comparing the ACLR and MLKR cohort that had injuries specifically during pivoting sports, the IKDC (p < 0.001) and TAS (p = 0.009) were higher in the ACLR group at 6 months, and the ACL-RSI was higher at 6 (p < 0.001) and 12 (p = 0.007) months, there were no further differences. Hop and knee extensor strength LSIs were lower (p < 0.05) in the full MLKR (versus ACLR) cohort at all timepoints (apart from the 24-month SHD LSI). However, the ACLR group only demonstrated greater LSIs than the pivoting sport MLKR for the SHD at 6 months (p < 0.001), and knee extensor strength at 6 (p < 0.001) and 12 (p < 0.001) months. CONCLUSIONS: While the recovery of patients undergoing MLKR due to a pivoting sports injury is delayed compared with their ACLR counterparts, the clinical outcome and activity profile are similar by 24 months. LEVEL OF EVIDENCE: Level IV.

Modern multiligament knee injury surgical reconstruction techniques can achieve excellent knee function and patient satisfaction, with low complication rates.

PURPOSE: To report on the recovery of strength and functional capacity symmetry following multiligament knee surgical reconstruction (MLKR), as well as the capacity of athletes to return to sport. METHODS: This prospective cohort study recruited 47 patients undergoing MLKR between February 2018 and July 2021. Forty patients had full outcome assessment postoperatively at 6, 12 and 24 months and were included in the analysis, 75% were knee dislocation one injuries and 60% were injured playing sport. Patient-reported outcome measures (PROMs) assessed included the International Knee Documentation Committee score, the Knee Outcome Survey, the Lysholm Knee Score and the Tegner Activity Scale (TAS). Patient satisfaction was also assessed. Objective assessment included assessment of active knee flexion and extension range of motion (ROM), the single (single horizontal hop for distance [SHD]) and triple (triple horizontal hop for distance [THD]) hop tests for distance and peak isokinetic knee flexor/extensor torque. RESULTS: All PROMs significantly improved (p < 0.001) from presurgery to 24 months postsurgery. At 24 months, 70% of patients were satisfied with their sports participation. Active knee flexion (p < 0.0001) and extension (p < 0.0001) ROM significantly improved over time, as did the limb symmetry indices (LSIs) for the SHD (p < 0.0001), THD (p < 0.0001), peak knee extensor (p < 0.0001) and flexor (p = 0.012) torque. While LSIs for the SHD, THD and knee flexor strength tended to plateau by 12 months, knee extensor strength continued to improve from 12 to 24 months. CONCLUSIONS: The majority of patients undergoing modern MLKR surgical techniques and rehabilitation can achieve excellent knee function, with low complication rates. LEVEL OF EVIDENCE: Level IV.

Detection of Bacteria in Bladder Mucosa of Adult Females.

PURPOSE: Interstitial cystitis/bladder pain syndrome is a chronic urological condition diagnosed in nearly 8 million females in the United States. Whether urinary microbiota play an etiological role remains controversial. Most studies assessed the microbiota of interstitial cystitis/bladder pain syndrome patients with voided or catheterized urine as a proxy for bladder urothelium; however, urine may not be a true reflection of the bladder microbiota. Bladder biopsy tissue may provide a more accurate, and thus more clinically relevant, picture of bladder microbiota. MATERIALS AND METHODS: Bladder biopsy tissues were obtained from: (1) 30 females with interstitial cystitis/bladder pain syndrome (18-80 years old) via cystoscopically guided cold-cup biopsy following therapeutic bladder hydrodistention, and (2) 10 non-interstitial cystitis/bladder pain syndrome females undergoing pelvic organ prolapse repair. To detect bacteria, technical duplicates of each RNAlater-preserved biopsy were subjected to 16S rRNA gene sequencing. To visualize bacteria, paraformaldehyde-fixed, paraffin-embedded biopsies were subjected to a combined multiplexed fluorescence in situ hybridization and fluorescence immunohistochemistry assay and confocal microscopy. RESULTS: Bacteria were detected by 16S rRNA gene sequencing in at least 1 technical duplicate of most biopsies. The most abundant genus was Staphylococcus, followed by Lactobacillus; Escherichia was common but not abundant. There was no significant difference between interstitial cystitis/bladder pain syndrome patients and controls (P > .05). Combined fluorescence in situ hybridization and immunohistochemistry reproducibly detected 16S rRNA in epithelial cells and shed cells in the urothelium and lesioned areas and capillary walls in the lamina propria of human bladder biopsy tissue. CONCLUSIONS: We conclude that urothelial and urinary microbiota are similar but not identical in adult females.

Understanding the physics of hydrophobic solvation.

Simulations of water near extended hydrophobic spherical solutes have revealed the presence of a region of depleted density and accompanying enhanced density fluctuations. The physical origin of both phenomena has remained somewhat obscure. We investigate these effects employing a mesoscopic binding potential analysis, classical density functional theory (DFT) calculations for a simple Lennard-Jones solvent, and Grand Canonical Monte Carlo (GCMC) simulations of a monatomic water (mw) model. We argue that the density depletion and enhanced fluctuations are near-critical phenomena. Specifically, we show that they can be viewed as remnants of the critical drying surface phase transition that occurs at bulk liquid-vapor coexistence in the macroscopic planar limit, i.e., as the solute radius Rs → ∞. Focusing on the radial density profile ρ(r) and a sensitive spatial measure of fluctuations, the local compressibility profile χ(r), our binding potential analysis provides explicit predictions for the manner in which the key features of ρ(r) and χ(r) scale with Rs, the strength of solute-water attraction ɛsf, and the deviation from liquid-vapor coexistence of the chemical potential, δµ. These scaling predictions are confirmed by our DFT calculations and GCMC simulations. As such, our theory provides a firm basis for understanding the physics of hydrophobic solvation.

Molecular underpinnings of ssDNA specificity by Rep HUH-endonucleases and implications for HUH-tag multiplexing and engineering.

Replication initiator proteins (Reps) from the HUH-endonuclease superfamily process specific single-stranded DNA (ssDNA) sequences to initiate rolling circle/hairpin replication in viruses, such as crop ravaging geminiviruses and human disease causing parvoviruses. In biotechnology contexts, Reps are the basis for HUH-tag bioconjugation and a critical adeno-associated virus genome integration tool. We solved the first co-crystal structures of Reps complexed to ssDNA, revealing a key motif for conferring sequence specificity and for anchoring a bent DNA architecture. In combination, we developed a deep sequencing cleavage assay, termed HUH-seq, to interrogate subtleties in Rep specificity and demonstrate how differences can be exploited for multiplexed HUH-tagging. Together, our insights allowed engineering of only four amino acids in a Rep chimera to predictably alter sequence specificity. These results have important implications for modulating viral infections, developing Rep-based genomic integration tools, and enabling massively parallel HUH-tag barcoding and bioconjugation applications.

Re: Pentosan polysulfate and a pigmentary maculopathy: causation versus correlation?

How should a conscientious physician advise patients with Interstitial Cystitis /Bladder Pain Syndrome (IC/BPS) when they want to know if taking Pentosan Polysulfate Sodium (PPS) will lead to loss of vision? Ever since the initial report from Pearce et al in 2018 suggesting that PPS usage can lead to the development of pigmented maculopathy (PM), my patients have been inundated with solicitations from attorneys looking to sign up clients for class action lawsuits.1 While there have been additional reports suggesting a relationship between PPS exposure and the development of PM, Ludwig et al found that there was no difference in the rate of macular disease between patients with documented IC/BPS who had taken PPS and those with IC/BPS with no history of PPS use.2 The large size of Ludwig's study certainly suggests that PPS may not cause PM to develop, and if the rate of PM in the IC population is higher than in controls, it may be due to the disease itself and not from the medication. In this manuscript, Proctor clearly describes the immune inflammatory response that is responsible for the development of the bladder damage seen with IC/BPS. Also, he describes how inflammatory mediators can enter the blood stream and might be a potential cause for the development of PM.3 This is a thought-provoking hypothesis that demands further evaluation. I have prescribed PPS since its approval and have many patients who feel it is an essential part of their IC treatment regimen. There is no other prescription medication that functions in the same fashion. I require them to follow the FDA recommendations for annual eye exams to look for PM development. I also advise patients that as they improve, we will discuss dose reduction and even discontinuation if their IC symptoms have abated. By following these suggestions, one should be able to continue to prescribe PPS for appropriate patients while carefully monitoring them for PM. I found this article extremely informative and will refer to it when counseling patients about IC/BPS and PPS.

Bidirectional titration of yeast gene expression using a pooled CRISPR guide RNA approach.

Most classic genetic approaches utilize binary modifications that preclude the identification of key knockdowns for essential genes or other targets that only require moderate modulation. As a complementary approach to these classic genetic methods, we describe a plasmid-based library methodology that affords bidirectional, graded modulation of gene expression enabled by tiling the promoter regions of all 969 genes that comprise the ito977 model of Saccharomyces cerevisiae's metabolic network. When coupled with a CRISPR-dCas9-based modulation and next-generation sequencing, this method affords a library-based, bidirection titration of gene expression across all major metabolic genes. We utilized this approach in two case studies: growth enrichment on alternative sugars, glycerol and galactose, and chemical overproduction of betaxanthins, leading to the identification of unique gene targets. In particular, we identify essential genes and other targets that were missed by classic genetic approaches.

Correction: 15-keto-prostaglandin E2 activates host peroxisome proliferator-activated receptor gamma (PPAR-γ) to promote Cryptococcus neoformans growth during infection.

[This corrects the article DOI: 10.1371/journal.ppat.1007597.].

Density Depletion and Enhanced Fluctuations in Water near Hydrophobic Solutes: Identifying the Underlying Physics.

We investigate the origin of the density depletion and enhanced density fluctuations that occur in water in the vicinity of an extended hydrophobic solute. We argue that both phenomena are remnants of the critical drying surface phase transition that occurs at liquid-vapor coexistence in the macroscopic planar limit, i.e., as the solute radius R_{s}→∞. Focusing on the density profile ρ(r) and a sensitive spatial measure of fluctuations, the local compressibility profile χ(r), we develop a scaling theory which expresses the extent of the density depletion and enhancement in compressibility in terms of R_{s}, the strength of solute-water attraction ϵ_{s}, and the deviation from liquid-vapor coexistence δµ. Testing the predictions against results of classical density functional theory for a simple solvent and grand canonical Monte Carlo simulations of a popular water model, we find that the theory provides a firm physical basis for understanding how water behaves at a hydrophobe.

The acute phase protein lactoferrin is a key feature of Alzheimer's disease and predictor of Aß burden through induction of APP amyloidogenic processing.

Amyloidogenic processing of the amyloid precursor protein (APP) forms the amyloid-ß peptide (Aß) component of pathognomonic extracellular plaques of AD. Additional early cortical changes in AD include neuroinflammation and elevated iron levels. Activation of the innate immune system in the brain is a neuroprotective response to infection; however, persistent neuroinflammation is linked to AD neuropathology by uncertain mechanisms. Non-parametric machine learning analysis on transcriptomic data from a large neuropathologically characterised patient cohort revealed the acute phase protein lactoferrin (Lf) as the key predictor of amyloid pathology. In vitro studies showed that an interaction between APP and the iron-bound form of Lf secreted from activated microglia diverted neuronal APP endocytosis from the canonical clathrin-dependent pathway to one requiring ADP ribosylation factor 6 trafficking. By rerouting APP recycling to the Rab11-positive compartment for amyloidogenic processing, Lf dramatically increased neuronal Aß production. Lf emerges as a novel pharmacological target for AD that not only modulates APP processing but provides a link between Aß production, neuroinflammation and iron dysregulation.

HRMAn 2.0: Next-generation artificial intelligence-driven analysis for broad host-pathogen interactions.

To study the dynamics of infection processes, it is common to manually enumerate imaging-based infection assays. However, manual counting of events from imaging data is biased, error-prone and a laborious task. We recently presented HRMAn (Host Response to Microbe Analysis), an automated image analysis program using state-of-the-art machine learning and artificial intelligence algorithms to analyse pathogen growth and host defence behaviour. With HRMAn, we can quantify intracellular infection by pathogens such as Toxoplasma gondii and Salmonella in a variety of cell types in an unbiased and highly reproducible manner, measuring multiple parameters including pathogen growth, pathogen killing and activation of host cell defences. Since HRMAn is based on the KNIME Analytics platform, it can easily be adapted to work with other pathogens and produce more readouts from quantitative imaging data. Here we showcase improvements to HRMAn resulting in the release of HRMAn 2.0 and new applications of HRMAn 2.0 for the analysis of host-pathogen interactions using the established pathogen T. gondii and further extend it for use with the bacterial pathogen Chlamydia trachomatis and the fungal pathogen Cryptococcus neoformans.

The coexistence curve and surface tension of a monatomic water model.

We study the monatomic water model of Molinero and Moore the grand canonical ensemble Monte Carlo simulation. Measurements of the probability distribution of the number density obtained via multicanonical sampling and histogram reweighting provide accurate estimates of the temperature dependence of both the liquid-vapor coexistence densities and the surface tension. Using finite-size scaling methods, we locate the liquid-vapor critical point at Tc = 917.6 K, ρc = 0.311 g cm-3. When plotted in scaled variables, in order to test the law of corresponding states, the coexistence curve of monatomic water is close to that of real water. In this respect, it performs better than extended simple point charge (SPC/E), TIP4P, and TIP4P/2005 water.

Pulsed electromagnetic field (PEMF) as an adjunct therapy for pain management in interstitial cystitis/bladder pain syndrome.

INTRODUCTION AND HYPOTHESIS: Patients with interstitial cystitis/bladder pain syndrome (IC/BPS) often experience chronic pelvic and even systemic pain that can be difficult to clinically manage. Pulsed electromagnetic field (PEMF) therapy, a non-invasive strategy that has shown significant efficacy for pain reduction in other chronic pain conditions, may provide benefit for pain management in patients with IC/BPS. METHODS: PEMF delivery to patients occurs via a bio-electromagnetic-energy device which consists of a flexible mat (180 × 50 cm) that the patient lies on for systemic, full-body delivery and/or a flexible pad (50 × 15 cm) for targeted delivery to a specific body region (e.g., pelvic area). The duration of individual sessions, number of sessions per day, total number of sessions, and follow-up observation period vary between previously published studies. Positive outcomes are typically reported as a significant reduction in visual analog scale (VAS) pain score and functional improvement assessed using validated questionnaires specific to the condition under study. RESULTS AND CONCLUSIONS: The use of PEMF has been evaluated as a therapeutic strategy for pain management in several clinical scenarios. Randomized, double-blinded, placebo-controlled trials have reported positive efficacy and safety profiles when PEMF was used to treat non-specific low back pain, patellofemoral pain syndrome, chronic post-operative pain, osteoarthritis-related pain, rheumatoid arthritis-related pain, and fibromyalgia-related pain. Based on these positive outcomes in a variety of pain conditions, clinical trials to evaluate whether PEMF can provide a safe, non-invasive therapeutic approach to improve symptoms of chronic pain and fatigue in patients with IC/BPS are warranted.

Functional genomic analyses of IC/BPS patient subgroups: a pilot study.

INTRODUCTION: To further facilitate understanding of disease pathophysiology and patient stratification in interstitial cystitis/bladder pain syndrome (IC/BPS), we utilized molecular phenotyping to compare three clinically distinct IC/BPS patient subgroups. MATERIALS AND METHODS: Total RNA (miRNA and mRNA) was isolated via standard protocols from IC/BPS patient bladder biopsies and assayed on whole genome and microRNA expression arrays. Data from three patient subgroups (n = 4 per group): (1) low bladder capacity (BC; ≤ 400 cc) without Hunner's lesion, (2) low BC with Hunner's lesion, and (3) non-low BC (> 400 cc) were used in comparative analyses to evaluate the influence of BC and HL on gene expression profiles in IC/BPS. RESULTS: The BC comparison (Group 1 v 3) identified 54 miRNAs and 744 mRNAs. Eleven miRNAs mapped to 40 genes. Hierarchical clustering of miRNA revealed two primary clusters: (1) 3/4 low BC patients; (2) 4/4 non-low and 1/4 low BC patients. Clustering of mRNA provided clear separation based on BC. The HL comparison (Group 1 v 2) identified 16 miRNAs and 917 mRNAs. 4 miRNAs mapped to 13 genes. Clustering of miRNA and mRNA revealed clear separation based on HL status. CONCLUSIONS: Significant molecular differences in IC/BPS were found to be associated with the low BC phenotype (e.g., an upregulation of cell proliferation and inflammation marker genes), as well as additional molecular findings that further define the HL+ phenotype (e.g., upregulation of genes involved in bioenergetics reactions) and suggest oxidative stress may play a role.

A unified description of hydrophilic and superhydrophobic surfaces in terms of the wetting and drying transitions of liquids.

Clarifying the factors that control the contact angle of a liquid on a solid substrate is a long-standing scientific problem pertinent across physics, chemistry, and materials science. Progress has been hampered by the lack of a comprehensive and unified understanding of the physics of wetting and drying phase transitions. Using various theoretical and simulational techniques applied to realistic fluid models, we elucidate how the character of these transitions depends sensitively on both the range of fluid-fluid and substrate-fluid interactions and the temperature. Our calculations uncover previously unrecognized classes of surface phase diagram which differ from that established for simple lattice models and often assumed to be universal. The differences relate both to the topology of the phase diagram and to the nature of the transitions, with a remarkable feature being a difference between drying and wetting transitions which persists even in the approach to the bulk critical point. Most experimental and simulational studies of liquids at a substrate belong to one of these previously unrecognized classes. We predict that while there appears to be nothing particularly special about water with regard to its wetting and drying behavior, superhydrophobic behavior should be more readily observable in experiments conducted at high temperatures than at room temperature.

SHORT Syndrome: Systematic Appraisal of the Medical and Dental Phenotype.

INTRODUCTION: SHORT syndrome is a rare autosomal dominant condition described by its acronym of short stature, hyperextensibility of joints and/or inguinal hernia, ocular depression, Rieger abnormality, and teething delay. Individuals have a distinct progeroid craniofacial appearance with a triangular face, frontal bossing, hypoplastic or thin alae nasi, large low-set ears, and mandibular retrognathia. OBJECTIVES: To systematically appraise the literature and update the clinical phenotype with emphasis on the dental condition. DESIGN: A systematic literature search was carried out to update the clinical phenotype, identifying reports of individuals with SHORT syndrome published after August 2015. The same search strategy but not limited to publication date was carried out to identify reports of the dental phenotype. Two independent reviewers screened 1937 articles with 55 articles identified for full-text review. RESULTS: Nineteen individuals from 11 families were identified. Facial dysmorphism including ocular depression, triangular shaped face, frontal bossing, large low-set ears, and micrognathia were the most consistent features followed by lipodystrophy, insulin resistance, and intrauterine growth restriction. Teething delay, microdontia, hypodontia, and enamel hypoplasia have all been reported. CONCLUSION: Features that comprise the SHORT acronym do not accurately or completely describe the clinical phenotype. The craniofacial appearance is one of the most consistent features. Lipodystrophy and insulin resistance may also be considered cardinal features. After teething delay, enamel hypoplasia and microdontia are the most common dental manifestations. We present recommendations for the dental and orthodontic/orthognathic management of individuals with SHORT syndrome.

X-linked hypophosphatemic rickets: Orthodontic considerations and management. A case report.

X-linked hypophosphatemic rickets (XLH) is a rare condition affecting bone metabolism. It has characteristic dental features such as poorly mineralised dentine, spontaneous abscess formation in the absence of caries and taurodontism. There are limited published data about patients with this condition undergoing orthodontic treatment, and there is no clear guideline on the suitability of orthodontic treatment in this cohort. We present a case report of a patient with XLH with a confirmed PHEX gene mutation undergoing orthodontic treatment and clinical recommendations to support treatment.

15-keto-prostaglandin E2 activates host peroxisome proliferator-activated receptor gamma (PPAR-γ) to promote Cryptococcus neoformans growth during infection.

Cryptococcus neoformans is one of the leading causes of invasive fungal infection in humans worldwide. C. neoformans uses macrophages as a proliferative niche to increase infective burden and avoid immune surveillance. However, the specific mechanisms by which C. neoformans manipulates host immunity to promote its growth during infection remain ill-defined. Here we demonstrate that eicosanoid lipid mediators manipulated and/or produced by C. neoformans play a key role in regulating pathogenesis. C. neoformans is known to secrete several eicosanoids that are highly similar to those found in vertebrate hosts. Using eicosanoid deficient cryptococcal mutants Δplb1 and Δlac1, we demonstrate that prostaglandin E2 is required by C. neoformans for proliferation within macrophages and in vivo during infection. Genetic and pharmacological disruption of host PGE2 synthesis is not required for promotion of cryptococcal growth by eicosanoid production. We find that PGE2 must be dehydrogenated into 15-keto-PGE2 to promote fungal growth, a finding that implicated the host nuclear receptor PPAR-γ. C. neoformans infection of macrophages activates host PPAR-γ and its inhibition is sufficient to abrogate the effect of 15-keto-PGE2 in promoting fungal growth during infection. Thus, we describe the first mechanism of reliance on pathogen-derived eicosanoids in fungal pathogenesis and the specific role of 15-keto-PGE2 and host PPAR-γ in cryptococcosis.