12 research outputs found

    MDA5 signaling induces type 1 IFN- and IL-1-dependent lung vascular permeability which protects mice from opportunistic fungal infection

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    Lungs balance threat from primary viral infection, secondary infection, and inflammatory damage. Severe pulmonary inflammation induces vascular permeability, edema, and organ dysfunction. We previously demonstrated that poly(I:C) (pICLC) induced type 1 interferon (t1IFN) protected mice from Cryptococcus gattii (Cg) via local iron restriction. Here we show pICLC increased serum protein and intravenously injected FITC-dextran in the lung airspace suggesting pICLC induces vascular permeability. Interestingly, pICLC induced a pro-inflammatory signature with significant expression of IL-1 and IL-6 which depended on MDA5 and t1IFN. Vascular permeability depended on MDA5, t1IFN, IL-1, and IL-6. T1IFN also induced MDA5 and other MDA5 signaling components suggesting that positive feedback contributes to t1IFN dependent expression of the pro-inflammatory signature. Vascular permeability, induced by pICLC or another compound, inhibited Cg by limiting iron. These data suggest that pICLC induces t1IFN which potentiates pICLC-MDA5 signaling increasing IL-1 and IL-6 resulting in leakage of antimicrobial serum factors into lung airspace. Thus, induced vascular permeability may act as an innate defense mechanism against opportunistic fungal infection, such as cryptococcosis, and may be exploited as a host-directed therapeutic target

    Demonstrating a Statistically Significant Association Between Anal High-Grade Squamous Intraepithelial Lesion and Positive OncoE6 Anal Test in Men Who Have Sex With Men and are Living With HIV

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    OBJECTIVES: The aim of the study is to determine whether a positive OncoE6 Anal Test result has statistically significant higher odds of being associated with high-grade squamous intraepithelial lesion (HSIL) and to calculate sensitivity and specificity of this test for predicting HSIL in adult men who have sex with men and are living with HIV (MSMLWH). MATERIALS AND METHODS: Men living with HIV 18 years or older having ≥atypical squamous cells of undetermined significance-grade anal cytology results were eligible to enroll in this cross-sectional study. Anal samples were collected just before the high-resolution anoscopy procedure. OncoE6 Anal Test results were compared with histology, the reference standard. Sensitivity, specificity, and odds ratio were calculated using HSIL as the threshold. RESULTS: Two hundred seventy-seven consented MSMLWH were enrolled between June 2017 and January 2022. Of these, 219 (79.1%) had biopsies obtained and histology performed; 81 of 219 participants (37%) had 1 or more biopsies with HSIL results while the remaining 138 of 219 (63%) had only low-grade squamous intraepithelial lesion or were negative for dysplasia. Anal samples from 7 participants (8.6%, 7/81) with HSIL and 3 (2.2%, 3/138) with low-grade squamous intraepithelial lesion had positive OncoE6 Anal Test results. Odds of having HSIL were 4.26 times higher among participants testing positive for HPV16/HPV18 E6 oncoprotein(s) (OR = 4.26, 95% CI = 1.07-16.95, p = .04). The OncoE6 Anal Test demonstrated excellent specificity, 97.83% (93.78-99.55), but poor sensitivity, 8.64% (3.55-17.0). CONCLUSIONS: In this highest-risk population for anal cancer, one could combine the OncoE6 Anal Test, having excellent specificity, with the anal Pap test, having higher sensitivity. Patients found having both an abnormal anal Pap and positive OncoE6 Anal Test result could be triaged for rapid scheduling of their high-resolution anoscopy

    Pulmonary Iron Limitation Induced by Exogenous Type I IFN Protects Mice from Cryptococcus gattii Independently of T Cells

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    Cryptococcus neoformans and Cryptococcus gattii cause fatal infection in immunodeficient and immunocompetent individuals. While these fungi are sibling species, C. gattii infects very few AIDS patients, while C. neoformans infection is an AIDS-defining illness, suggesting that the host response to HIV selects C. neoformans over C. gattii. We used a viral mimic molecule (pICLC) to stimulate the immune response, and pICLC treatment improved mouse outcomes from both species. pICLC-induced action against C. neoformans was due to activation of well-defined immune pathways known to deter C. neoformans, whereas these immune pathways were dispensable for pICLC treatment of C. gattii. Since these immune pathways are eventually destroyed by HIV/AIDS, our data help explain why the antiviral immune response in AIDS patients is unable to control C. neoformans infection but is protective against C. gattii. Furthermore, pICLC induced tighter control of iron in the lungs of mice, which inhibited C. gattii, thus suggesting an entirely new mode of nutritional immunity activated by viral signals.Cryptococcus neoformans causes deadly mycosis primarily in AIDS patients, whereas Cryptococcus gattii infects mostly non-HIV patients, even in regions with high burdens of HIV/AIDS and an established environmental presence of C. gattii. As HIV induces type I IFN (t1IFN), we hypothesized that t1IFN would differentially affect the outcome of C. neoformans and C. gattii infections. Exogenous t1IFN induction using stabilized poly(I·C) (pICLC) improved murine outcomes in either cryptococcal infection. In C. neoformans-infected mice, pICLC activity was associated with C. neoformans containment and classical Th1 immunity. In contrast, pICLC activity against C. gattii did not require any immune factors previously associated with C. neoformans immunity: T, B, and NK cells, IFN-γ, and macrophages were all dispensable. Interestingly, C. gattii pICLC activity depended on β-2-microglobulin, which impacts iron levels among other functions. Iron supplementation reversed pICLC activity, suggesting C. gattii pICLC activity requires iron limitation. Also, pICLC induced a set of iron control proteins, some of which were directly inhibitory to cryptococcus in vitro, suggesting t1IFN regulates iron availability in the pulmonary air space fluids. Thus, exogenous induction of t1IFN significantly improves the outcome of murine infection by C. gattii and C. neoformans but by distinct mechanisms; the C. gattii effect was mediated by iron limitation, while the effect on C. neoformans infection was through induction of classical T-cell-dependent immunity. Together this difference in types of T-cell-dependent t1IFN immunity for different Cryptococcus species suggests a possible mechanism by which HIV infection may select against C. gattii but not C. neoformans
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