Development and evaluation of a host-targeted antiviral that abrogates herpes simplex virus replication through modulation of arginine-associated metabolic pathways.

Since their inception five decades ago, most antivirals have been engineered to disrupt a single viral protein or process that is essential for viral replication. This approach has limited the overall therapeutic effectiveness and applicability of current antivirals due to restricted viral specificity, a propensity for development of drug resistance, and an inability to control deleterious host-mediated inflammation. As obligate intracellular parasites, viruses are reliant on host metabolism and macromolecular synthesis pathways. Of these biosynthetic processes, many viruses, including Herpes simplex viruses (HSV), are absolutely dependent on the bioavailability of arginine, a non-essential amino acid that is critical for many physiological and pathophysiological processes associated with either facilitating viral replication or progression of disease. To assess if targeting host arginine-associated metabolic pathways would inhibit HSV replication, a pegylated recombinant human Arginase I (peg-ArgI) was generated and its in vitro anti-herpetic activity was evaluated. Cells continuously treated with peg-ArgI for over 48 h exhibited no signs of cytotoxicity or loss of cell viability. The antiviral activity of peg-ArgI displayed a classical dose-response curve with IC50's in the sub-nanomolar range. peg-ArgI potently inhibited HSV-1 and HSV-2 viral replication, infectious virus production, cell-to-cell spread/transmission and virus-mediated cytopathic effects. Not unexpectedly given its host-targeted mechanism of action, peg-ArgI showed similar effectiveness at controlling replication of single and multidrug resistant HSV-1 mutants. These findings illustrate that targeting host arginine-associated metabolic pathways is an effective means of controlling viral replicative processes. Further exploration into the breadth of viruses inhibited by peg-ArgI, as well as the ability of peg-ArgI to suppress arginine-associated virus-mediated pathophysiological disease processes is warranted.

Increase of Frequency and Modulation of Phenotype of Regulatory T Cells by Atorvastatin Is Associated with Decreased Lung Inflammatory Cell Infiltration in a Murine Model of Acute Allergic Asthma.

Regulatory T cells (Tregs) play an important role by controlling allergic inflammation of airways. Recently, it has been shown that statins have immunomodulatory properties, probably mediated by their effects on Tregs. Therefore, we evaluated the in vivo effect of atorvastatin (ATV) on Tregs and its association with the inflammatory process in a model of allergic asthma. BALB/c mice were sensitized with ovalbumin (OVA) and then challenged with intranasal OVA. ATV (40 mg/kg) was delivered by daily intraperitoneal injection for 7 or 15 days before each OVA challenge. ATV treatment for 7 days increased the frequency of Tregs in mediastinal lymph nodes (MLN) and the interleukin (IL)-10 in lungs. After 15 days of treatment, ATV increased the percentage of glucocorticoid-induced tumor necrosis factor receptor-related protein (GITR+) and programmed cell death protein 1 (PD-1+) Tregs in the lung, without enhancing their suppressive activity, but also increased the percentage of conventional T cells expressing GITR+, PD1+, and OX-40 (tumor necrosis factor receptor superfamily member 4). Although no significant changes were observed in the number of inflammatory cells in the bronchoalveolar lavage (BAL), OVA-specific immunoglobulin E in the serum, and type 2 helper (Th2) cytokines in the lungs, there was a significant decrease of peribronchial inflammation that negatively correlated with the Tregs in MLN and the concentration of IL-10 in the lung. These results suggest that ATV has an immunomodulatory role possibly mediated by their effects on Tregs, which could contribute to the control of inflammation during allergic asthma. Further studies are necessary to elucidate the contribution of Treg to immunomodulatory action of statins in the context of allergic asthma.

Angioedema hereditario en Medellín, Colombia: evaluación clínica y de la calidad de vida / Hereditary angioedema in Medellín (Colombia): Clinical evaluation and quality of life appraisal

Introducción. El angioedema hereditario es una inmunodeficiencia primaria de carácter autosómico dominante, debida a un déficit en la proteína inhibidora del factor C1 y caracterizada por episodios recurrentes de edema subcutáneo y de las mucosas. Las impredecibles y frecuentes crisis de angioedema afectan la calidad de vida de los individuos que las padecen. Objetivo. Analizar las características clínicas de una familia con un caso índice de angioedema hereditario y determinar el impacto de la enfermedad en la calidad de vida. Materiales y métodos. En el estudio se incluyeron 26 miembros de la familia, a 25 de los cuales se les midieron los niveles sanguíneos del factor C4 del complemento y del inhibidor de C1 antigénico y funcional. Se utilizaron dos instrumentos, el SF-36 para evaluar la salud del adulto y el KIDSCREEN-27 para la calidad de vida de niños y adolescentes. Resultados. El 83 % de los individuos que reportaron síntomas cumplían con los criterios serológicos del angioedema hereditario de tipo I: valores bajos del factor C4 del complemento y del inhibidor de C1 cuantitativo (antigénico) y cualitativo (funcional). Se encontró que la calidad de vida en cuanto al bienestar psicológico y el desempeño emocional de los pacientes, se veía considerablemente afectada por los síntomas de la enfermedad. Conclusión. Este estudio provee información sobre la primera familia caracterizada con angioedema hereditario de tipo 1 en el Valle de Aburrá, Colombia. Aunque para ello se usó un instrumento genérico, se confirmó, además, el efecto negativo de la enfermedad en la calidad de vida de los individuos que la padecen.

Introduction: Hereditary angioedema is an autosomal dominant primary immunodeficiency caused by a deficiency of the C1 inhibitor protein and characterized by recurrent episodes of subcutaneous and mucosal edema. Unpredictable and frequent crisis of angioedema affect the quality of life of individuals suffering this kind of disorder. Objective: To analyze the clinical characteristics of a family with an index case of hereditary angioedema and to determine the impact of this disease on their quality of life. Materials and methods: Twenty six members of the family were included in the trial; 25 of them were analyzed for C4 complement and antigenic and functional C1 inhibitor blood levels. Two instruments (SF-365 and KIDSCREEN-27) were used to evaluate adult health quality and children and teenagers quality of life, respectively. Results: Eighty three percent (83%) of individuals reporting symptoms of the condition exhibited serological criteria of hereditary angioedema type I: low levels of both C4 complement and quantitative (antigenic) and qualitative (functional) C1 inhibitor. In relation to patients' psychological and emotional performance, their quality of life was significantly affected by the symptoms of hereditary angioedema. Conclusion: This study provides evidence of the first family in Valle de Aburrá (Colombia) characterized as having hereditary angioedema type I. Despite the use of a generic instrument, the negative impact on the quality of life of individuals suffering this disease was also confirmed.

[Hereditary angioedema in Medellín (Colombia): Clinical evaluation and quality of life appraisal]. / Angioedema hereditario en Medellín, Colombia: evaluación clínica y de la calidad de vida.

INTRODUCTION: Hereditary angioedema is an autosomal dominant primary immunodeficiency caused by a deficiency of the C1 inhibitor protein and characterized by recurrent episodes of subcutaneous and mucosal edema. Unpredictable and frequent crisis of angioedema affect the quality of life of individuals suffering this kind of disorder. OBJECTIVE: To analyze the clinical characteristics of a family with an index case of hereditary angioedema and to determine the impact of this disease on their quality of life. MATERIALS AND METHODS: Twenty six members of the family were included in the trial; 25 of them were analyzed for C4 complement and antigenic and functional C1 inhibitor blood levels. Two instruments (SF-365 and KIDSCREEN-27) were used to evaluate adult health quality and children and teenagers quality of life, respectively. RESULTS: Eighty three percent (83%) of individuals reporting symptoms of the condition exhibited serological criteria of hereditary angioedema type I: low levels of both C4 complement and quantitative (antigenic) and qualitative (functional) C1 inhibitor. In relation to patients' psychological and emotional performance, their quality of life was significantly affected by the symptoms of hereditary angioedema. CONCLUSION: This study provides evidence of the first family in Valle de Aburrá (Colombia) characterized as having hereditary angioedema type I. Despite the use of a generic instrument, the negative impact on the quality of life of individuals suffering this disease was also confirmed.

Activation of apoptosis, but not necrosis, during Mycobacterium tuberculosis infection correlated with decreased bacterial growth: role of TNF-alpha, IL-10, caspases and phospholipase A2.

Monocyte/macrophage cell death is an important event during mycobacterial infection. To get insights about the influence of mononuclear phagocyte maturation in this event we compared the response to Mycobacterium tuberculosis (Mtb) infection of fresh isolated monocytes and monocyte-derived macrophages (MDM) from healthy tuberculin positive individuals. Both monocytes and MDM underwent apoptosis, however, there was a higher numbers of apoptotic macrophages with active Caspases 8 and 9. We also compared Mtb-induced cell death in U937 pro-monocytes and PMA-differentiated cells (U937D). In response to Mtb infection, U937D cells underwent apoptosis and promonocytes both apoptosis and necrosis. There were high number of U937D cells producing TNF-alpha and high number of IL-10+ promonocytes. These evidences suggest that U937 could be a valid model to study the mechanisms that rule Mtb-induced cell death. Experiments with the cell line and fresh isolated mononuclear cells with pharmacological inhibitors showed that induction of necrosis involved calcium and cAMP signals resulting in IL-10 production. Necrosis also correlated with Caspase 3, PLA2 activity and bacterial growth. In U937D cells and monocytes from healthy donors there was activation of calcium, TNF-alpha and Caspase 8 activation and decreased bacterial load. Understanding the mechanisms that control the dichotomy events between apoptosis and necrosis/oncosis associated with cell maturity might open new strategies to better control the course of mycobacterial infections.