Examinando por Autor "Cabrera, Alex"

Mostrando 1 - 2 de 2
  • Miniatura
    Ítem
    Engineering the Osmotic State of Pseudomonas putida KT2440 for Efficient Cell Disruption and Downstream Processing of Poly(3-Hydroxyalkanoates)
    (Frontiers Media S.A., 2020-03) Poblete-Castro, Ignacio; Aravena-Carrasco, Carla; Orellana-Saez, Matias; Pacheco, Nicolás; Cabrera, Alex
    In the last decade, the development of novel programmable cell lytic systems based on different inducible genetic constructs like the holin–endolysin and lysozyme appears as a promising alternative to circumvent the use of costly enzymes and mechanical disrupters for downstream processing of intracellular microbial products. Despite the advances, upon activation of these systems the cellular disruption of the biocatalyst occurs in an extended period, thus delaying the recovery of poly(3-hydroxyalkanoate) (PHA). Herein the osmotic state of Pseudomonas putida KT2440 was engineered by inactivating the inner-membrane residing rescue valve MscL, which is responsible mainly for circumventing low-osmolarity challenges. Then the major outer membrane porin OprF and the specific porin OprE were overproduced during PHA producing conditions on decanoate-grown cells. The engineered P. putida strains carrying each porin showed no impairment on growth rate and final biomass and PHA yield after 48 h cultivation. Expression of both porins in tandem in the mutant strain KTΔmscL-oprFE led to a slight reduction of the biomass synthesis (∼10%) but higher PHA accumulation (%wt) relative to the cell dry mass. Each strain was then challenged to an osmotic upshift for 1 h and subsequently to a rapid passage to a hypotonic condition where the membrane stability of the KTΔmscL-oprFE suffered damage, resulting in a rapid reduction of cell viability. Cell disruption accounted for >95% of the cell population within 3 h as reported by colony forming units (CFU), FACS analyses, and transmission electron microscopy. PHA recovery yielded 94.2% of the biosynthesized biopolymer displaying no significant alterations on the final monomer composition. This study can serve as an efficient genetic platform for the recovery of any microbial intracellular compound allowing less unit operation steps for cellular disruption. © Copyright © 2020 Poblete-Castro, Aravena-Carrasco, Orellana-Saez, Pacheco, Cabrera and Borrero-de Acuña.
  • No hay miniatura disponible
    Ítem
    Humoral and cellular response induced by a second booster of an inactivated SARS-CoV-2 vaccine in adults
    (Elsevier B.V., 2023-05) Méndez, Constanza; Peñaloza, Hernán F.; Schultz, Bárbara M.; Piña-Iturbe, Alejandro; Ríos, Mariana; Moreno-Tapia, Daniela; Pereira-Sánchez, Patricia; Leighton, Diane; Orellana, Claudia; Covarrubias, Consuelo; Gálvez, Nicolás M.S.; Soto, Jorge A.; Duarte, Luisa F.; Rivera-Pérez, Daniela; Vázquez, Yaneisi; Cabrera, Alex; Bustos, Sergio; Iturriaga, Carolina; Urzua, Marcela; Navarrete, María S.; Rojas, Álvaro; Fasce, Rodrigo A.; Fernández, Jorge; Mora, Judith; Ramírez, Eugenio; Gaete-Argel, Aracelly; Acevedo, Mónica; Valiente-Echeverría, Fernando; Soto-Rifo, Ricardo; Weiskopf, Daniela; Grifoni, Alba; Sette, Alessandro; Zeng, Gang; Meng, Weining; Del Río, Constanza; Del Pino, Dinely; Aguirre, Natalia; Salinas, Grecia; Vega, Franco; Salgado, Acsa; Quinteros, Thomas; Ortiz, Marlene; Puente, Marcela; Muñoz, Alma; Astudillo, Patricio; Le Corre, Nicole; Potin, Marcela; Catalán, Juan; Peralta, Melan; Zamanillo, Consuelo; Keller, Nicole; Fernández, Rocío; Aljaro, Sofía; López, Sofía; González, José Tomás; Weil, Tania; Opazo, Luz; Muñoz, Paula; Estay, Inés; Cantillana, Miguel; Carrera, Liliana; Masalleras, Matías; Guzmán, Paula; Aguirre, Francisca; Cortés, Aarón; Bátiz, Luis Federico; Pérez, Javiera; Apablaza, Karen; Yates, Lorena; Valdés, María de los Ángeles; Hurtado, Bernardita; Venteneul, Veronique; Astorga, Constanza; Muñoz-Venturelli, Paula; Vial, Pablo A.; Schilling, Andrea; Pavez, Daniela; Pérez, Inia; Riviotta, Amy; González, Francisca; Urrutia, Francisca; Del Río, Alejandra; Asenjo, Claudia; Vargas, Bárbara; Castro, Francisca; Acuña, Alejandra; Guzmán, Javiera; Astudillo, Camila; Pérez, Carlos M.; Espinoza, Pilar; Martínez, Andrea; Arancibia, Marcela; Romero, Harold; Bustamante, Cecilia; Pérez, María Loreto; Uribe, Natalia; Silva, Viviana; Morice, Bernardita; Pérez, Marco; González, Marcela; Jensen, Werner; Pasten, Claudia; Aguilera, M. Fernanda; Martínez, Nataly; Molina, Camila; Arrieta, Sebastián; López, Begoña; Ortiz, Claudia; Escobar, Macarena; Bustamante, Camila; Espinoza, Marcia; Pardo, Angela; Carrasco, Alison; Montes, Miguel; Saldías, Macarena; Gutiérrez, Natalia; Sánchez, Juliette; Fuentes, Daniela; Calvo, Yolanda; Cepeda, Mariela; Lemus, Rosario; Suárez, Muriel; Armijo, Mercedes; Monsalves, Shirley; Marucich, Constance; Cornejo, Cecilia; Acosta, Ángela; Prado, Xaviera; Yáñez, Francisca; Barroeta, Marisol; López, Claudia; Donato, Paulina; Lasso, Martin; Iturrieta, María; Giraldo, Juan; Gutiérrez, Francisco; Acuña, María; Cascone, Ada; Rojas, Raymundo; Sepúlveda, Camila; Contreras, Mario; Campisto, Yessica; González, Pablo A.; Quizhpi, Zoila; López, Mariella; Pizzeghello, Vania; Silva, Stephannie; González-Aramundiz, José V.; Abarca, Katia; Melo-González, Felipe; Bueno, Susan M.; Kalergis, Alexis M.
    Background: The Omicron variant has challenged the control of the COVID-19 pandemic due to its immuno-evasive properties. The administration of a booster dose of a SARS-CoV-2 vaccine showed positive effects in the immunogenicity against SARS-CoV-2, effect that is even enhanced after the administration of a second booster. Methods: During a phase-3 clinical trial, we evaluated the effect of a second booster of CoronaVac®, an inactivated vaccine administered 6 months after the first booster, in the neutralization of SARS-CoV-2 (n = 87). In parallel, cellular immunity (n = 45) was analyzed in stimulated peripheral mononuclear cells by flow cytometry and ELISPOT. Findings: Although a 2.5-fold increase in neutralization of the ancestral SARS-CoV-2 was observed after the second booster when compared with prior its administration (Geometric mean units p < 0.0001; Geometric mean titer p = 0.0002), a poor neutralization against the Omicron variant was detected. Additionally, the activation of specific CD4+ T lymphocytes remained stable after the second booster and, importantly, equivalent activation of CD4+ T lymphocytes against the Omicron variant and the ancestral SARS-CoV-2 were found. Interpretation: Although the neutralizing response against the Omicron variant after the second booster of CoronaVac® was slightly increased, these levels are far from those observed against the ancestral SARS-CoV-2 and could most likely fail to neutralize the virus. In contrast, a robust CD4+T cell response may confer protection against the Omicron variant. Funding: The Ministry of Health, Government of Chile, the Confederation of Production and Commerce, Chile and SINOVAC Biotech. NIH NIAID. The Millennium Institute on Immunology and Immunotherapy. © 2023 The Author(s)