Browsing by Author "Angulo, J."

Now showing 1 - 9 of 9
  • No Thumbnail Available
    Item
    Assessment of Mutations Associated With Genomic Variants of SARS-CoV-2: RT-qPCR as a Rapid and Affordable Tool to Monitoring Known Circulating Variants in Chile, 2021
    (2022) Angulo, J.; Martinez Valdebenito, C.; Pardo Roa, C.; Almonacid, L. I.; Fuentes Luppichini, E.; Contreras, A. M.; Maldonado, C.; Le Corre, N.; Melo Ledermann, Francisco Javier; Medina, R. A.; Ferrés, M.
    Since the first report of SARS-CoV-2 infection in humans, the virus has mutated to develop new viral variants with higher infection rates and more resistance to neutralization by antibodies elicited after natural SARS-CoV-2 infection or by vaccines. Therefore, rapid identification of viral variants circulating in the population is crucial for epidemiological assessment and efforts to contain the resurgence of the pandemic. Between January and November 2021, we performed a large variant RT-qPCR-based screening of mutations in the spike protein of 1851 SARS-CoV-2-positive samples derived from outpatients from the UC-Christus Health Network in Chile. In a portion of samples (n = 636), we validated our RT-qPCR-pipeline by WGS, obtaining a 99.2% concordance. Our results indicate that from January to March 2021 there was a dominance of non-identifiable variants by the RT-qPCR-based screening; however, throughout WGS we were able to identify the Lambda (C.37) variant of interest (VOI). From March to July, we observed the rapid emergence of mutations associated with the Gamma variant (P.1), which was quickly replaced by the appearance of a combination of samples harboring mutations associated with the Delta variant (B.1.617.2), which predominated until the end of the study. Our results highlight the applicability of cost-effective RT-qPCR-based screening of mutations associated with known variants of concern (VOC), VOI and variants under monitoring (VUM) of SARS-CoV-2, being a rapid and reliable tool that complements WGS-based surveillance.
  • Thumbnail Image
    Item
    Correlation between female sex, IL28B genotype, and the clinical severity of bronchiolitis in pediatric patients
    (2020) Astudillo, P.; Angulo, J.; Pino, K.; de Carvalho, J. B.; de Morais, G. L.; Perez, S.; de Vasconcelos, A. T. R.; Ferrés, Marcela; López Lastra, Marcelo Andrés
  • Thumbnail Image
    Item
    Detection of high biliary and fecal viral loads in patients with chronic hepatitis C virus infection
    (2017) Monrroy Bravo, Hugo Alfonso; Angulo, J.; Pino, Karla; Labbé, P.; Miquel P., Juan Francisco; López Lastra, Marcelo Andrés; Soza, Alejandro
  • Thumbnail Image
    Item
    Effect of ezetimibe in HCV viral load after liver transplantation
    (2016) Monrroy Bravo, Hugo Alfonso; Angulo, J.; Pino, Karla; Labbé, P.; López Lastra, Marcelo Andrés; Soza, Alejandro
  • Thumbnail Image
    Item
    Is Gamma (P.1) Variant Associated with a Higher Severity in ICU Patients with SARS-CoV-2 Infection
    (2022) Vera, M.; Angulo, J.; Medina, R.; Ferres, M.; Bruhn, A.; Castro, R.; Pardo-Roa, C.
    The Omicron variant of SARS-CoV-2 has been shown to evade neutralizing antibodies elicited by vaccination or infection. Despite the global spread of the Omicron variant, even among highly vaccinated populations, death rates have not increased concomitantly. These data suggest that immune mechanisms beyond antibody-mediated virus neutralization may protect against severe disease. In addition to neutralizing pathogens, antibodies contribute to control and clearance of infections through Fc effector mechanisms. Here, we probed the ability of vaccine-induced antibodies to drive Fc effector activity against the Omicron variant using samples from individuals receiving one of three SARS-CoV-2 vaccines. Despite a substantial loss of IgM, IgA, and IgG binding to the Omicron variant receptor binding domain (RBD) in samples from individuals receiving BNT162b2, mRNA-1273, and CoronaVac vaccines, stable binding was maintained against the full-length Omicron Spike protein. Compromised RBD binding IgG was accompanied by a loss of RBD-specific antibody Fc gamma receptor (Fe gamma R) binding in samples from individuals who received the CoronaVac vaccine, but RBD-specific Fc gamma R2a and Fc gamma R3a binding was preserved in recipients of mRNA vaccines. Conversely, Spike protein-specific antibodies exhibited persistent but reduced binding to Fc gamma Rs across all three vaccines, although higher binding was observed in samples from recipients of mRNA vaccines. This was associated with preservation of Fc gamma R2a and Fc gamma R3a binding antibodies and maintenance of Spike protein-specific antibody-dependent natural killer cell activation. Thus, despite the loss of Omicron neutralization, vaccine-induced Spike protein-specific antibodies continue to drive Fc effector functions, suggesting a capacity for extraneutralizing antibodies to contribute to disease control.
  • Thumbnail Image
    Item
    LOOP IIId of the HCV IRES is essential for the structural rearrangement of the 40S-HCV IRES complex
    (2016) Angulo, J.; Ulryck, N.; Deforges, J.; Chamond, N.; López Lastra, Marcelo Andrés; Masquida, B.; Sargueil, B.
  • Thumbnail Image
    Item
    Molecular Description of a Novel Orientia Species Causing Scrub Typhus in Chile
    (2020) Abarca Villaseca, Katia; Martinez-Valdebenito, C.; Angulo, J.; Jiang, J.; Farris, C. M.; Richards, A. L.; Acosta-Jamett, G.; Weitzel, T.
  • Thumbnail Image
    Item
    Mother-to-child transmission of Andes virus through breast milk, Chile
    (2020) Ferrés, Marcela; Martínez Valdebenito, Constanza; Angulo, J.; Henríquez, C.; Vera Otarola, Jorge Andrés; Vergara, M. J.; Vial Cox, María Cecilia; Vial Claro, Pablo; Pérez, J.; Le Corre Pérez, Monique Nicole; Fernández, J.; Sotomayor, V.; Valdés, M. F.; González-Candia, D.; Tischler, N. D.; Mertz, G.
  • Thumbnail Image
    Item
    Urinary leukotriene and Bcl I polymorphism of glucocorticoid receptor gene in preschoolers with recurrent wheezing and high risk of asthma
    (2016) Morales, M.; Flores, C.; Pino, Karla; Angulo, J.; López Lastra, Marcelo Andrés; Castro Rodríguez, José Antonio