396 research outputs found

    Genital HSV-2 Infection Induces Short-Term NK Cell Memory

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    NK cells are known as innate immune cells that lack immunological memory. Recently, it has been shown that NK cells remember encounters with chemical haptens that induce contact hypersensitivity and cytomegalovirus infection. Here, we show the existence of NK cell memory following HSV-2 infection. Stimulation with HSV-2 Ags led to higher IFNΞ³ production in NK cells that were exposed 30 days previously to HSV-2, compared to NK cells from naΓ―ve mice. More importantly, this increased production of IFNΞ³ in NK cells was independent of B- and T- lymphocytes and specific for the HSV-2 Ags. We also showed that previously exposed NK cells in a B- and T-lymphocyte free environment mediate protection against HSV-2 infection and they are necessary for the protection of mice against HSV-2 infection. Collectively, NK cells remember prior HSV-2 encounters independent of B- and T- lymphocytes leading to protection against HSV-2 mediated morbidity and mortality upon re-exposure

    AHR signaling is induced by infection with coronaviruses

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    Coronavirus infection in humans is usually associated to respiratory tract illnesses, ranging in severity from mild to life-threatening respiratory failure. The aryl hydrocarbon receptor (AHR) was recently identified as a host factor for Zika and dengue viruses; AHR antagonists boost antiviral immunity, decrease viral titers and ameliorate Zika-induced pathology in vivo. Here we report that AHR is activated by infection with different coronaviruses, potentially impacting antiviral immunity and lung epithelial cells. Indeed, the analysis of single-cell RNA-seq from lung tissue detected increased expression of AHR and AHR transcriptional targets, suggesting AHR signaling activation in SARS-CoV-2-infected epithelial cells from COVID-19 patients. Moreover, we detected an association between AHR expression and viral load in SARS-CoV-2 infected patients. Finally, we found that the pharmacological inhibition of AHR suppressed the replication in vitro of one of the causative agents of the common cold, HCoV-229E, and the causative agent of the COVID-19 pandemic, SARS-CoV-2. Taken together, these findings suggest that AHR activation is a common strategy used by coronaviruses to evade antiviral immunity and promote viral replication, which may also contribute to lung pathology. Future studies should further evaluate the potential of AHR as a target for host-directed antiviral therapy.Fil: Giovannoni, Federico. Consejo Nacional de Investigaciones CientΓ­ficas y TΓ©cnicas; Argentina. Harvard Medical School; Estados UnidosFil: Li, Zhaorong. Harvard Medical School; Estados UnidosFil: Remes Lenicov, Federico. Consejo Nacional de Investigaciones CientΓ­ficas y TΓ©cnicas. Oficina de CoordinaciΓ³n Administrativa Houssay. Instituto de Investigaciones BiomΓ©dicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones BiomΓ©dicas en Retrovirus y Sida; ArgentinaFil: DΓ‘vola, MarΓ­a E.. McMaster University; CanadΓ‘Fil: Elizalde, Maria Mercedes. Consejo Nacional de Investigaciones CientΓ­ficas y TΓ©cnicas. Oficina de CoordinaciΓ³n Administrativa Houssay. Instituto de Investigaciones BiomΓ©dicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones BiomΓ©dicas en Retrovirus y Sida; ArgentinaFil: Paletta, Ana Luz. Consejo Nacional de Investigaciones CientΓ­ficas y TΓ©cnicas. Oficina de CoordinaciΓ³n Administrativa Houssay. Instituto de Investigaciones BiomΓ©dicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones BiomΓ©dicas en Retrovirus y Sida; ArgentinaFil: Ashkar, Ali A.. McMaster University; CanadΓ‘Fil: Mossman, Karen L.. McMaster University; CanadΓ‘Fil: Dugour, Andrea Vanesa. Consejo Nacional de Investigaciones CientΓ­ficas y TΓ©cnicas; ArgentinaFil: Figueroa, Juan Manuel. Consejo Nacional de Investigaciones CientΓ­ficas y TΓ©cnicas. Oficina de CoordinaciΓ³n Administrativa Parque Centenario. Instituto de Ciencia y TecnologΓ­a "Dr. CΓ©sar Milstein". FundaciΓ³n Pablo CassarΓ‘. Instituto de Ciencia y TecnologΓ­a "Dr. CΓ©sar Milstein"; ArgentinaFil: Barquero, Andrea Alejandra. Consejo Nacional de Investigaciones CientΓ­ficas y TΓ©cnicas. Oficina de CoordinaciΓ³n Administrativa Ciudad Universitaria. Instituto de QuΓ­mica BiolΓ³gica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de QuΓ­mica BiolΓ³gica de la Facultad de Ciencias Exactas y Naturales; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de QuΓ­mica BiolΓ³gica. Laboratorio de VirologΓ­a; ArgentinaFil: Ceballos, Ana. Consejo Nacional de Investigaciones CientΓ­ficas y TΓ©cnicas. Oficina de CoordinaciΓ³n Administrativa Houssay. Instituto de Investigaciones BiomΓ©dicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones BiomΓ©dicas en Retrovirus y Sida; ArgentinaFil: Garcia, Cybele. Consejo Nacional de Investigaciones CientΓ­ficas y TΓ©cnicas. Oficina de CoordinaciΓ³n Administrativa Ciudad Universitaria. Instituto de QuΓ­mica BiolΓ³gica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de QuΓ­mica BiolΓ³gica de la Facultad de Ciencias Exactas y Naturales; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de QuΓ­mica BiolΓ³gica; ArgentinaFil: Quintana, Francisco Javier. Broad Institute; Estados Unidos. Harvard Medical School; Estados Unido

    Characterization of Barley Genotypes and Their Biochemical Responses against Leaf Rust (Puccinia hordei) Disease under Cold Arid Environment

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    Cereal rust is one of the most damaging diseases of small-grain cereals. The fungus Puccinia hordei causes leaf rust in barley and other small grain crops. Puccinia hordei causes serious yield losses in the cultivating areas where susceptible and late-maturing barley varieties are cultivated. Therefore, rust-resistant barley cultivar is highly demandable for sustainable small-grain crop production. Improving barley yields and quality is one of the major objectives of barley breeding programs in our country. Exotic and indigenous germplasm is one of the best sources of resistance to biotic stresses in barley particularly leaf rust caused by Puccinia hordei. Hence, the present investigation was carried out to identify the resistance sources to P. hordei and incorporate them into the breeding programs for higher barley yields under changing climatic scenarios. The study aimed to identify new resistant cultivars in barley and other small grain crops. In this study, 100 barley genotypes (Hordeum vulgare L.) were considered for screening susceptibility to P. hordei causing rust disease. Several biochemical responses were analyzed in P. hordei infected barley genotypes. However, the variable response was observed among the 100 barley genotypes while those were screened against leaf rust disease under high altitude cold arid conditions of Ladakh, India. The efficiency of the 100 barley genotypes were categorized into different classes including high resistance (4 genotypes)>resistance (14 genotypes)> moderately resistance (20 genotypes)> moderately susceptible (33 genotypes)>moderately susceptible to susceptible (19 genotypes)> and susceptible (10 genotypes) based on plant response to P. hordei. Among the total genotypes, SHEIKH/KP-706, SHEIKH-B1, SHEIKH-636, and IC-062190 showed high resistance (8.07-8.63) as per the international leaf rust scale, while EC-667381, EC-667390, EC-667392, EC667396, EC-667417, Jyoti, EC-667434, EC-667442, EC-667445, and EC-667446 were found as susceptible (3.13-3.97) to P. hordei. The highly resistant genotypes accumulated a high level of phenols and flavonoids and cooperated with susceptible and other rest of the genotypes in response to P. hordei rust. The efficiency of plant immune response and or fitness to P. hordei was correlated to the disease susceptibility index of particular genotypes. This provides a new insight and the mechanistic basis of genotype-specific rust disease susceptibility against P. hordei. A large number of genotype-based studies at the field level could be useful to plant breeders and farmers for improving rust resistance in barley and other small-grain cereals

    Interleukin-15 Treatment Induces Weight Loss Independent of Lymphocytes

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    Obesity is a chronic inflammatory condition characterized by activation and infiltration of proinflammatory immune cells and a dysregulated production of proinflammatory cytokines. While known as a key regulator of immune natural killer (NK) cell function and development, we have recently demonstrated that reduced expression of the cytokine Interleukin-15 (IL-15) is closely linked with increased body weight and adiposity in mice and humans. Previously, we and others have shown that obese individuals have lower circulating levels of IL-15 and NK cells. Lean IL-15 overexpressing (IL-15 tg) mice had an accumulation in adipose NK cells compared to wildtype and NK cell deficient obese IL-15βˆ’/βˆ’ mice. Since IL-15 induces weight loss in IL-15βˆ’/βˆ’ and diet induced obese mice and has effects on various lymphocytes, the aim of this paper was to determine if lymphocytes, particularly NK cells, play a role in IL-15 mediated weight loss. Acute IL-15 treatment resulted in an increased accumulation of NK, NKT, and CD3+ T cells in adipose tissue of B6 mice. Mice depleted of NK and NKT cells had similar weight loss comparable to controls treated with IL-15. Finally, IL-15 treatment induces significant weight loss in lymphocyte deficient RAG2βˆ’/βˆ’Ξ³cβˆ’/βˆ’ mice independent of food intake. Fat pad cross-sections show decreased pad size with cytokine treatment is due to adipocyte shrinkage. These results clearly suggest that IL-15 mediates weight loss independent of lymphocytes

    Search for dark matter annihilation signals in the H.E.S.S. Inner galaxy survey

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    The central region of the MilkyΒ Way is one of the foremost locations to look for dark matter (DM) signatures. We report the first results on a search for DM particle annihilation signals using new observations from an unprecedented Ξ³-ray survey of the Galactic Center (GC) region, i.e., the Inner Galaxy Survey, at very high energies (≳100  GeV) performed with the H.E.S.S. array of five ground-based Cherenkov telescopes. No significant Ξ³-ray excess is found in the search region of the 2014-2020 dataset and a profile likelihood ratio analysis is carried out to set exclusion limits on the annihilation cross section βŸ¨Οƒv⟩. Assuming Einasto and Navarro-Frenk-White (NFW) DM density profiles at the GC, these constraints are the strongest obtained so far in the TeV DM mass range. For the Einasto profile, the constraints reachΒ βŸ¨Οƒv⟩ values of 3.7Γ—10^{-26}  cm^{3} s^{-1} for 1.5Β TeV DM mass in the W^{+}W^{-} annihilation channel, and 1.2Γ—10^{-26}  cm^{3} s^{-1} for 0.7Β TeV DM mass in the Ο„^{+}Ο„^{-} annihilation channel. With the H.E.S.S. Inner Galaxy Survey, ground-based Ξ³-ray observations thus probe βŸ¨Οƒv⟩ values expected from thermal-relic annihilating TeV DM particles

    Resveratrol Prevents Endothelial Cells Injury in High-Dose Interleukin-2 Therapy against Melanoma

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    Immunotherapy with high-dose interleukin-2 (HDIL-2) is an effective treatment for patients with metastatic melanoma and renal cell carcinoma. However, it is accompanied by severe toxicity involving endothelial cell injury and induction of vascular leak syndrome (VLS). In this study, we found that resveratrol, a plant polyphenol with anti-inflammatory and anti-cancer properties, was able to prevent the endothelial cell injury and inhibit the development of VLS while improving the efficacy of HDIL-2 therapy in the killing of metastasized melanoma. Specifically, C57BL/6 mice were injected with B16F10 cells followed by resveratrol by gavage the next day and continued treatment with resveratrol once a day. On day 9, mice received HDIL-2. On day 12, mice were evaluated for VLS and tumor metastasis. We found that resveratrol significantly inhibited the development of VLS in lung and liver by protecting endothelial cell integrity and preventing endothelial cells from undergoing apoptosis. The metastasis and growth of the tumor in lung were significantly inhibited by HDIL-2 and HDIL-2 + resveratrol treatment. Notably, HDIL-2 + resveratrol co-treatment was more effective in inhibiting tumor metastasis and growth than HDIL-2 treatment alone. We also analyzed the immune status of Gr-1+CD11b+ myeloid-derived suppressor cells (MDSC) and FoxP3+CD4+ regulatory T cells (Treg). We found that resveratrol induced expansion and suppressive function of MDSC which inhibited the development of VLS after adoptive transfer. However, resveratrol suppressed the HDIL-2-induced expansion of Treg cells. We also found that resveratrol enhanced the susceptibility of melanoma to the cytotoxicity of IL-2-activated killer cells, and induced the expression of the tumor suppressor gene FoxO1. Our results suggested the potential use of resveratrol in HDIL-2 treatment against melanoma. We also demonstrated, for the first time, that MDSC is the dominant suppressor cell than regulatory T cell in the development of VLS

    Polymorphisms in Toll-like receptor genes influence antibody responses to cytomegalovirus glycoprotein B vaccine

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    <p>Abstract</p> <p>Background</p> <p>Congenital Cytomegalovirus (CMV) infection is an important medical problem that has yet no current solution. A clinical trial of CMV glycoprotein B (gB) vaccine in young women showed promising efficacy. Improved understanding of the basis for prevention of CMV infection is essential for developing improved vaccines.</p> <p>Results</p> <p>We genotyped 142 women previously vaccinated with three doses of CMV gB for single nucleotide polymorphisms (SNPs) in TLR 1-4, 6, 7, 9, and 10, and their associated intracellular signaling genes. SNPs in the platelet-derived growth factor receptor (PDGFRA) and integrins were also selected based on their role in binding gB. Specific SNPs in TLR7 and IKBKE (inhibitor of nuclear factor kappa-B kinase subunit epsilon) were associated with antibody responses to gB vaccine. Homozygous carriers of the minor allele at four SNPs in TLR7 showed higher vaccination-induced antibody responses to gB compared to heterozygotes or homozygotes for the common allele. SNP rs1953090 in IKBKE was associated with changes in antibody level from second to third dose of vaccine; homozygotes for the minor allele exhibited lower antibody responses while homozygotes for the major allele showed increased responses over time.</p> <p>Conclusions</p> <p>These data contribute to our understanding of the immunogenetic mechanisms underlying variations in the immune response to CMV vaccine.</p

    Osteopontin Impairs Host Defense during Established Gram-Negative Sepsis Caused by Burkholderia pseudomallei (Melioidosis)

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    Melioidosis is a severe tropical disease caused by infection with the bacterium Burkholderia (B.) pseudomallei. In northeast Thailand infection with this bacterium is the major cause of community-acquired septicemia with a mortality rate up to 40%. Extending the knowledge on the mechanisms of host defense against B. pseudomallei infection would be helpful to improve treatment of this severe illness. Osteopontin (OPN) is a cytokine that is involved in several immune responses that occur during bacterial infection. In this study, we investigated levels of OPN in patients with melioidosis, and studied the function of OPN during experimental melioidosis in mice. We found that OPN concentrations were elevated in patients with severe melioidosis, and that high OPN concentrations are associated with poor outcome in patients with melioidosis. In experimental melioidosis in mice plasma and lung OPN levels were also increased. Moreover, mice with melioidosis that were deficient for OPN demonstrated reduced bacterial numbers in their lungs, diminished pulmonary tissue injury, and decreased neutrophil infiltration into the lungs during established melioidosis. Moreover, these mice displayed a delayed mortality as compared to control mice. In conclusion, sustained production of OPN impairs host defense during melioidosis

    A MeerKAT, e-MERLIN, H.E.S.S. and Swift search for persistent and transient emission associated with three localised FRBs

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