Search results for "Interferons"

Cytokine-mediated regulation of monocyte/macrophage cytotoxicity in human immunodeficiency virus-1 infection.

1992

Monocyte/macrophage-mediated tumor cytotoxicity was studied in patients infected with human immunodeficiency virus-1 (HIV-1) at various stages [Center for disease control (CDC) classification] of the disease. using the P-815 tumor cell line as target cells, the results demonstrated reduced monocyte/macrophage cytotoxicity early in HIV-1-related disease (CDCIII, P0.01). This cellular dysfunction sustained during the progression of the disease. Evidence could be presented that neither exogenous application of macrophage-stimulating cytokines (e.g. interferons) nor their endogenous induction in vitro restored monocyte/macrophage cytotoxicity. However, enhanced tumor necrosis factor (TNF)-alpha…

Social evolution of innate immunity evasion in a virus

2019

Antiviral immunity has been studied extensively from the perspective of virus−cell interactions, yet the role of virus−virus interactions remains poorly addressed. Here, we demonstrate that viral escape from interferon (IFN)-based innate immunity is a social process in which IFN-stimulating viruses determine the fitness of neighbouring viruses. We propose a general and simple social evolution framework to analyse how natural selection acts on IFN shutdown and validate it in cell cultures and mice infected with vesicular stomatitis virus. Furthermore, we find that IFN shutdown is costly because it reduces short-term viral progeny production, thus fulfilling the definition of an altruistic tr…

How to optimize HCV therapy in genotype 1 patients: predictors of response.

2013

The advent of triple therapy (TT) with first-generation protease inhibitors boceprevir (BOC) and telaprevir (TVR) in addition to pegylated interferon and ribavirin (PEG-IFN/RBV) has resulted in a significant improvement in the sustained virological response (SVR) rate and potentially in life years gained compared to dual therapy (DT), when treating naive or treatment-experienced patients with genotype 1 (G1) chronic hepatitis C (CHC). This benefit is partly offset by the increased complexity of treatment, and the increased costs and risks of therapy, making it necessary to optimize the indications for TT. Naive patients with mild fibrosis and the IL28B CC polymorphism and/or with a rapid vi…

Interferons increase cell resistance to Staphylococcal alpha-toxin.

2007

ABSTRACTMany bacterial pathogens, includingStaphylococcus aureus, use a variety of pore-forming toxins as important virulence factors. Staphylococcal alpha-toxin, a prototype β-barrel pore-forming toxin, triggers the release of proinflammatory mediators and induces primarily necrotic death in susceptible cells. However, whether host factors released in response to staphylococcal infections may increase cell resistance to alpha-toxin is not known. Here we show that prior exposure to interferons (IFNs) prevents alpha-toxin-induced membrane permeabilization, the depletion of ATP, and cell death. Moreover, pretreatment with IFN-α decreases alpha-toxin-induced secretion of interleukin 1β (IL-1β)…

Efficacy of a 12-Week Simeprevir Plus Peginterferon/Ribavirin (PR) Regimen in Treatment-Naïve Patients with Hepatitis C Virus (HCV) Genotype 4 (GT4) …

2017

Background HCV GT4 accounts for up to 20% of HCV infections worldwide. Simeprevir, given for 12 weeks as part of a 24- or 48-week combination regimen with PR is approved for the treatment of chronic HCV GT4 infection. Primary study objectives were assessment of efficacy and safety of simeprevir plus PR in treatment-naïve patients with HCV GT4 treated for 12 weeks. Primary efficacy outcome was sustained virologic response 12 weeks post-treatment (SVR12). Additional objectives included investigation of potential associations of rapid virologic response and baseline factors with SVR12. Methods This multicentre, open-label, single-arm study (NCT01846832) evaluated efficacy and safety of simepre…

The KH-type splicing regulatory protein (KSRP) regulates type III interferon expression post-transcriptionally.

2019

Abstract Type III interferons (IFNs) are the latest members of the IFN family. They play an important role in immune defense mechanisms, especially in antiviral responses at mucosal sites. Moreover, they control inflammatory reactions by modulating neutrophil and dendritic cell functions. Therefore, it is important to identify cellular mechanisms involved in the control of type III IFN expression. All IFN family members contain AU-rich elements (AREs) in the 3′-untranslated regions (3′-UTR) of their mRNAs that determine mRNA half-life and consequently the expressional level of these cytokines. mRNA stability is controlled by different proteins binding to these AREs leading to either stabili…

DNASE1L3 deficiency, new phenotypes, and evidence for a transient type I IFN signaling.

2022

Background: Deoxyribonuclease 1 like 3 (DNASE1L3) is a secreted enzyme that has been shown to digest the extracellular chromatin derived from apoptotic bodies, and DNASE1L3 pathogenic variants have been associated with a lupus phenotype. It is unclear whether interferon signaling is sustained in DNASE1L3 deficiency in humans. Objectives: To explore interferon signaling in DNASE1L3 deficient patients. To depict the characteristic features of DNASE1L3 deficiencies in human. Methods: We identified, characterized, and analyzed five new patients carrying biallelic DNASE1L3 variations. Whole or targeted exome and/or Sanger sequencing was performed to detect pathogenic variations in five juvenile …

New glucocorticoids. Mechanisms of immunological activity at the cellular level and in the clinical setting.

1990

Rekombinanta hepatīta B vīrusa core antigēna imunoloģiski pētījumi; imunizētu dzīvnieku imunogenitātes novērtējums

2015

Darba mērķis bija noteikt HBcAg- ietvertas 63 nukleotīdus garas ODN sekvences ietekmi uz organisma imūno atbildes veidošanos un imunogenitāti, salīdzināt iegūtos rezultātus ar kontroles proteīniem – HBcAg un HBcAg- (proteīns, kam izņemta dabiskā E.coli NS, kas rodas ekspresijas laikā). No imunizētām BALB/c laboratorijas pelēm tika iegūti asins serumi un orgānu (liesa, limfmezgli) šūnu kultūras. Tika noteikta un salīdzināta proteīnu spēja inducēt antivielu sintēzi, šūnu kultūru proliferācijas indeksi 96 stundas pēc restimulācijas ar HBcAg- in vitro, CD4+ un CD8+ šūnu subpopulāciju pieaugums un savstarpējā skaita attiecība. Izmantojot komerciālus testus tika noteikta arī liesu šūnu kultūru su…

Management of hepatitis C virus genotype 4: recommendations of an international expert panel.

2011

HCV has been classified into no fewer than six major genotypes and a series of subtypes. Each HCV genotype is unique with respect to its nucleotide sequence, geographic distribution, and response to therapy. Genotypes 1, 2, and 3 are common throughout North America and Europe. HCV genotype 4 (HCV-4) is common in the Middle East and in Africa, where it is responsible for more than 80% of HCV infections. It has recently spread to several European countries. HCV-4 is considered a major cause of chronic hepatitis, cirrhosis, hepatocellular carcinoma, and liver transplantation in these regions. Although HCV-4 is the cause of approximately 20% of the 170 million cases of chronic hepatitis C in th…