Serotype-specific differences in inhibition of reovirus infectivity by human-milk glycans are determined by viral attachment protein σ1

AbstractHuman milk contains many bioactive components, including secretory IgA, oligosaccharides, and milk-associated proteins. We assessed the antiviral effects of several components of milk against mammalian reoviruses. We found that glucocerebroside (GCB) inhibited the infectivity of reovirus strain type 1 Lang (T1L), whereas gangliosides GD3 and GM3 and 3′-sialyllactose (3SL) inhibited the infectivity of reovirus strain type 3 Dearing (T3D). Agglutination of erythrocytes mediated by T1L and T3D was inhibited by GD3, GM3, and bovine lactoferrin. Additionally, α-sialic acid, 3SL, 6′-sialyllactose, sialic acid, human lactoferrin, osteopontin, and α-lactalbumin inhibited hemagglutination mediated by T3D. Using single-gene reassortant viruses, we found that serotype-specific differences segregate with the gene encoding the viral attachment protein. Furthermore, GD3, GM3, and 3SL inhibit T3D infectivity by blocking binding to host cells, whereas GCB inhibits T1L infectivity post-attachment. These results enhance an understanding of reovirus cell attachment and define a mechanism for the antimicrobial activity of human milk

Engineering Recombinant Reoviruses To Display gp41 Membrane-Proximal External-Region Epitopes from HIV-1

El objetivo es presentar categorías de la Teoría Histórico-Cultural de la Actividad como caja de herramientas para construir indagaciones e intervenciones vinculadas al trabajo de Psicólogos y otros Agentes en escenarios educativos. En el marco de problemas cruciales de agenda psicoeducativa, como el de las unidades de análisis, se introduce la Teoría de la Actividad en su primera, segunda y tercera generación y “más allá”, como Engestrom caracterizó su desarrollo histórico. Se presentan similaridades y diferencias con conceptualizaciones de autores de perspectivas socio-cultural e histórico–cultural, originadas en el pensamiento de Vygotsky, como Cole, Rogoff, Wertsch, Chaiklin, Daniels y Edwards, tanto en relación a la Psicología del Desarrollo como al giro relacional en la experticia. Se despliega la Teoría como artefacto mediador para construir investigaciones psicoeducativas en curso sobre violencias en escuelas desde la perspectiva de los actores y participación de psicólogos en configuraciones de apoyo entre Educación Especial y Escuela Común. Finalmente, conceptualizaciones y figuras diseñadas por Engestrom y Yamazumi, en la post-generación de la Teoría, permiten analizar procesos de vinculación e intercambio entre Universidad y Escuelas para la inclusión y calidad educativas, en los que participan psicólogos en formación y formadores de la Universidad Nacional de La Plata.The aim is to present categories of Cultural-Historic-Activity-Theory as a tools cage for the building of research and interventions related to Psychologists and other Agents´ work in educational stages. In the frame of central problems of the psycho-educational agenda, as the units of analysis, the Activity Theory is introduced in its first, second and third generation and beyond, as Engestrom depicted its historical development. Similarities and differences are presented between Activity Theory and conceptualizations of different authors of socio-cultural and cultural-historic perspectives, both founded on Vygotsky thought, linked to Development Psychology and to the relational shift in expertice, as Cole, Rogoff, Wertsch, Chaiklin, Daniels and Edwards. The Activity Theory is displayed as a mediating artifact for building current psycho-educational research about violences at school from the perspective of social actors and about psychologists and other agents´ participation in supportive configurations between Special Education and Common Schools. At last, figures and conceptualizations drawn by Engestrom and Yamazumi in the post-generation of the Theory, allow to analyse processes of linking and exchange between University and Schools for educational enhancement and inclusion, in which psychologists in modeling and tutors of La Plata National University are participating.Facultad de Psicologí

Specific Inhibition of Orai1-mediated Calcium Signalling Resolves Inflammation and Clears Bacteria in an ARDS Model

Rationale: Acute Respiratory Distress Syndrome (ARDS) has an unacceptably high mortality rate (35%) and is without effective therapy. Orai1 is a Ca 2+ channel involved in store operated Ca 2+ entry (SOCE), a process that exquisitely regulates inflammation. Orai1 is considered a druggable target, but to date, no Orai1-specific inhibitors exist. Objectives: To evaluate whether ELD607, a first-in-class Orai1 antagonist, can treat ARDS caused by bacterial pneumonia in preclinical models.  Methods: ELD607 pharmacology was evaluated in HEK293T cells and freshly-isolated ARDS patient immune cells. A murine acute lung injury model caused by bacterial pneumonia was then used. Mice were infected with P. aeruginosa, S. aureus, methicillin-resistant S. aureus (MRSA) or multidrug-resistant P. aeruginosa (MDR- Pa) and then treated with ELD607 intranasally. Measurements and Main Results: ELD607 specifically inhibited SOCE in HEK293T cells with an IC50 of 9 nM. ELD607 was stable in ARDS airway secretions and inhibited SOCE in ARDS immune cells. In vivo, inhaled ELD607 significantly reduced neutrophilia and improved survival. Surprisingly, Orai1 inhibition by ELD607 caused a significant reduction in lung bacteria, including MRSA. ELD607 worked as an immunomodulator that reduced cytokine levels, lowered neutrophilia and promoted both macrophage-mediated resolution of inflammation and clearance of bacteria. Indeed, when alveolar macrophages were depleted with inhaled clodronate, ELD607 was no longer able to resolve inflammation or clear bacteria. Conclusions: These data indicate that specific Orai1 inhibition by ELD607 may be a novel approach to reduce multi-organ inflammation and treat antibiotic-resistant bacteria. </p

Antiviral immunity via RIG-I-mediated recognition of RNA bearing 5'-diphosphates.

Mammalian cells possess mechanisms to detect and defend themselves from invading viruses. In the cytosol, the RIG-I-like receptors (RLRs), RIG-I (retinoic acid-inducible gene I; encoded by DDX58) and MDA5 (melanoma differentiation-associated gene 5; encoded by IFIH1) sense atypical RNAs associated with virus infection. Detection triggers a signalling cascade via the adaptor MAVS that culminates in the production of type I interferons (IFN-α and β; hereafter IFN), which are key antiviral cytokines. RIG-I and MDA5 are activated by distinct viral RNA structures and much evidence indicates that RIG-I responds to RNAs bearing a triphosphate (ppp) moiety in conjunction with a blunt-ended, base-paired region at the 5'-end (reviewed in refs 1, 2, 3). Here we show that RIG-I also mediates antiviral responses to RNAs bearing 5'-diphosphates (5'pp). Genomes from mammalian reoviruses with 5'pp termini, 5'pp-RNA isolated from yeast L-A virus, and base-paired 5'pp-RNAs made by in vitro transcription or chemical synthesis, all bind to RIG-I and serve as RIG-I agonists. Furthermore, a RIG-I-dependent response to 5'pp-RNA is essential for controlling reovirus infection in cultured cells and in mice. Thus, the minimal determinant for RIG-I recognition is a base-paired RNA with 5'pp. Such RNAs are found in some viruses but not in uninfected cells, indicating that recognition of 5'pp-RNA, like that of 5'ppp-RNA, acts as a powerful means of self/non-self discrimination by the innate immune system

Reovirus infection triggers inflammatory responses to dietary antigens and development of celiac disease

Viral infections have been proposed to elicit pathological processes leading to the initiation of T helper 1 (TH1) immunity against dietary gluten and celiac disease (CeD). To test this hypothesis and gain insights into mechanisms underlying virus-induced loss of tolerance to dietary antigens, we developed a viral infection model that makes use of two reovirus strains that infect the intestine but differ in their immunopathological outcomes. Reovirus is an avirulent pathogen that elicits protective immunity, but we discovered that it can nonetheless disrupt intestinal immune homeostasis at inductive and effector sites of oral tolerance by suppressing peripheral regulatory T cell (pTreg) conversion and promoting TH1 immunity to dietary antigen. Initiation of TH1 immunity to dietary antigen was dependent on interferon regulatory factor 1 and dissociated from suppression of pTreg conversion, which was mediated by type-1 interferon. Last, our study in humans supports a role for infection with reovirus, a seemingly innocuous virus, in triggering the development of CeD