Browsing by Author "Kalergis, Alexis"
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Publication Age and primary vaccination schedule impact humoral and cellular immunity with an inactivated SARS-CoV-2 vaccine(2025) Martínez, Yohana; Rodríguez, Linmar; Méndez, Constanza; Ríos, Mariana; Rivera, Daniela; Moreno, Daniela; Reyes, Humberto; Pereira, Patricia; Orellana, Claudia; Cabrera, Alex; Schultz, Bárbara; Duarte, Luisa; Gálvez, Nicolás; Melo, Felipe; Soto, Jorge; Iturriaga, Carolina; Urzúa, Marcela; Navarrete, Marıía; Rojas, Álvaro; Fasce, Rodrigo; Fernández, Jorge; Mora, Judith; Ramíez, Eugenio; Weiskopf, Daniela; Grifoni, Alba; Sette, Alessandro; Zeng, Gang; Meng, Weining; CoronaVac03CL Study Group; Alvarez, María; González, Jose; Domínguez, M. Angélica; González, Pablo; Abarca, Katia; Peñaloza, Hernán; Bueno, Susan; Kalergis, AlexisDespite widespread COVID-19 vaccination, questions remain about vaccine safety and immunogenicity in vulnerable populations, such as older adults. We evaluated the safety and immunogenicity of four doses of CoronaVac in adults above and below 60 who received the first two doses in two different schedules (0-14 and 0-28 days apart). While CoronaVac demonstrated excellent safety across age groups, older adults showed reduced reactogenicity. In the 0-28 schedule, both age groups exhibited similar frequencies of SARS-CoV-2-specific CD4+ and CD8+ T cells, though memory T cell distribution patterns differed. Notably, adults over 60 showed diminished virus-neutralizing antibody responses compared to younger participants. The 0-14 schedule produced equivalent cellular and neutralizing antibody responses between age groups, albeit at lower levels than the 0-28 schedule. Our data indicate that primary vaccination schedules can influence the humoral immune responses and memory T cell distribution between age groups.Publication Asymptomatic herpes simplex virus brain infection elicits cellular senescence phenotypes in the central nervous system of mice suffering multiple sclerosis-like disease(2024) Duarte, Luisa; Villalobos, Verónica; Farías, Mónica; Rangel, Maria; González, Enrique; Navarro, Areli; Carbone, Javier; Domínguez, Angélica; Alvarez, Alejandra; Riedel, Claudia; Bueno, Susan; Kalergis, Alexis; Cáceres, Mónica; González, PabloExperimental autoimmune encephalomyelitis (EAE) is a demyelinating disease affecting the central nervous system (CNS) in animals that parallels several clinical and molecular traits of multiple sclerosis in humans. Herpes simplex virus type 1 (HSV-1) infection mainly causes cold sores and eye diseases, yet eventually, it can also reach the CNS, leading to acute encephalitis. Notably, a significant proportion of healthy individuals are likely to have asymptomatic HSV-1 brain infection with chronic brain inflammation due to persistent latent infection in neurons. Because cellular senescence is suggested as a potential factor contributing to the development of various neurodegenerative disorders, including multiple sclerosis, and viral infections may induce a premature senescence state in the CNS, potentially increasing susceptibility to such disorders, here we examine the presence of senescence-related markers in the brains and spinal cords of mice with asymptomatic HSV-1 brain infection, EAE, and both conditions. Across all scenarios, we find a significant increases of senescence biomarkers in the CNS with some differences depending on the analyzed group. Notably, some senescence biomarkers are exclusively observed in mice with the combined conditions. These results indicate that asymptomatic HSV-1 brain infection and EAE associate with a significant expression of senescence biomarkers in the CNS.Item Cellular immune response induced by surface immunogenic protein with AbISCO-100 adjuvant vaccination decreases group B Streptococcus vaginal colonization.(Elsevier Ltd, 2019) Soto, Jorge; Diaz-Dinamarca, Diego; Soto, Daniel; Barrientos, Magaly; Carrión, Flavio; Kalergis, Alexis; Vásquez, AbelGroup B Streptococcus (GBS) represents one of the most common causes of bacterial infection in neonates; it is also associated with premature childbirth and stillbirth. A vaccine against GBS is needed, but no approved vaccines are yet available. The Surface Immunogenic Protein (SIP) of GBS is conserved in all serotypes and had been reported to be a good vaccine prototype in a mouse model of GBS infection. Also, we have previously shown that both subcutaneous and oral immunization with rSIP can induce an efficient immune response that decreases GBS vaginal colonization in mice. In this study, we show that a vaccine based on a mixture of rSIP and AbISCO-100 adjuvant reduces GBS vaginal colonization in mice and induces antibodies with opsonophagocytic activities. Moreover, the passive transfer of sera and total T-cells from mice immunized with rSIP mixed with AbISCO-100 to unvaccinated mice decreases vaginal GBS colonization in an infected mouse. This is the first report of cellular immunity associated with rSIP-based vaccine testing in a mouse model of GBS infection.Item Coagulation Factor Xa Promotes Solid Tumor Growth, Experimental Metastasis and Endothelial Cell Activation(Multidisciplinary Digital Publishing Institute (MDPI), 2019) Arce, Maximiliano; Pinto, Mauricio; Galleguillos, Macarena; Muñoz, Catalina; Lange, Soledad; Ramirez, Carolina; Erices, Rafaela; González, Pamela; Velásquez, Ethel; Tempio, Fabián; López, Mercedes; Salazar-Onfray, Flavio; Cautivo, Kelly; Kalergis, Alexis; Cruz, Sebastián; Lobos-González, Lorena; Lladser, Álvaro; Valenzuela, Guillermo; Olivares, Nixa; Sáez, Claudia; Koning, Tania; Sánchez, Fabiola; Fuenzalida, Patricia; Godoy, Alejandro; Contreras, Pamela; Leyton, Lisette; Lugano, Roberta; Dimberg, Anna; Quest, Andrew; Owen, GarethHypercoagulable state is linked to cancer progression; however, the precise role of the coagulation cascade is poorly described. Herein, we examined the contribution of a hypercoagulative state through the administration of intravenous Coagulation Factor Xa (FXa), on the growth of solid human tumors and the experimental metastasis of the B16F10 melanoma in mouse models. FXa increased solid tumor volume and lung, liver, kidney and lymph node metastasis of tail-vein injected B16F10 cells. Concentrating on the metastasis model, upon coadministration of the anticoagulant Dalteparin, lung metastasis was significantly reduced, and no metastasis was observed in other organs. FXa did not directly alter proliferation, migration or invasion of cancer cells in vitro. Alternatively, FXa upon endothelial cells promoted cytoskeleton contraction, disrupted membrane VE-Cadherin pattern, heightened endothelial-hyperpermeability, increased inflammatory adhesion molecules and enhanced B16F10 adhesion under flow conditions. Microarray analysis of endothelial cells treated with FXa demonstrated elevated expression of inflammatory transcripts. Accordingly, FXa treatment increased immune cell infiltration in mouse lungs, an effect reduced by dalteparin. Taken together, our results suggest that FXa increases B16F10 metastasis via endothelial cell activation and enhanced cancer cell-endothelium adhesion advocating that the coagulation system is not merely a bystander in the process of cancer metastasis.Publication Gestational hypothyroxinemia causes an inflammatory environment at maternal-fetal tissues and fetal brain with impaired hippocampal dendritic spine maturation in the offspring(2025) González, Enrique; Rangel, Andreina; Opazo, María; Espinoza, Sebastián; Elgueta, Daniela; Cancino, Gonzalo; Mery, Elena; Ardiles, Álvaro; Duarte, Luisa; Soto, Jorge; Carreño, Leandro; Simon, Felipe; Bueno, Susan; González, Pablo; Kalergis, AlexisGestational hypothyroxinemia (HTX) is associated with cognitive impairments and autism traits in offspring. However, the underlying mechanisms remain unclear. Prenatal inflammation impairs cortical development and induces diverse neurodevelopmental outcomes. Since thyroid dysfunction elicits inflammation, we sought to investigate whether HTX triggers prenatal pro-inflammatory responses. Using a mouse model of gestational HTX, we found elevated levels of IL-6 and IL-17 A in maternal serum, placental tissues, and embryonic brains at embryonic day (E)14 compared to euthyroid (EUT) dams. We also found increased proportions of dendritic cells, NK cells, M1-like macrophages, and monocytes in the placental tissues of HTX dams. Furthermore, gestational HTX exposure led to reduced Tbr2⁺ progenitors, increased Tbr1⁺ neurons, and an expanded Iba1⁺ microglial population in HTX-exposed embryos compared to EUT-exposed embryos. At postnatal day (P)55, the offspring gestated under HTX exhibited reduced hippocampal dendritic spine density and maturity compared to the progeny gestated under EUT. Notably, restoring T4 levels during HTX induction (HTX + T4 dams) prevented these alterations during pregnancy and in the offspring of HTX + T4 dams. These findings show that gestational HTX causes inflammation during pregnancy and has neurodevelopmental effects on the progeny, opening new pathways related to how maternal HTX impairs neurodevelopment in the offspring.Publication HSV-1 alters lipid metabolism and induces lipid droplet accumulation in functionally impaired mouse dendritic cells(2025) Farías, Mónica; Cancino, Felipe; Navarro, Areli; Duarte, Luisa; Soto, Abel; Tognarelli, Eduardo; Ramm, Maximiliano; Alarcón, Bárbara; Cordero, José; San Martín, Sergio; Agurto, Cristian; Retamal, Angello; Riedel, Claudia; Barrera, Nelson; Bustamante, Luis; Bueno, Susan; Kalergis, Alexis; González, PabloHerpes simplex virus type 1 (HSV-1) significantly impairs dendritic cell (DC) function, ultimately eliciting the death of these cells. Here, we sought to assess whether HSV-1 modulates lipid metabolism in mouse DCs as a mechanism of immune evasion. For this, we performed RT-qPCR gene arrays with ingenuity pathway analysis (IPA), RNA sequencing (RNA-seq) and gene set enrichment analysis (GSEA), confocal microscopy, transmission electron microscopy, ultra-high-performance liquid chromatography-quadrupole time-of-flight (UHPLC-QTOF) analysis, pharmacological inhibition of eight lipid-metabolism-related enzymes in HSV-1-infected DCs, co-cultures between virus-specific transgenic CD4+ and CD8+ T cells and HSV-1-infected DCs, and in vivo assays with mice. We found that HSV-1 significantly alters lipid metabolism in DCs and induces lipid droplet (LD) accumulation in these cells. Pharmacological inhibition of two particular lipid metabolism enzymes was found to partially restore DC function. Overall, these results suggest that lipid metabolism plays an important role in the impairment of DC function by HSV-1.Publication Safety and Non-Inferiority Evaluation of Two Immunization Schedules with an Inactivated SARS-CoV-2 Vaccine in Adults: A Randomized Clinical Trial(2022) Abarca, Katia; Iturriaga, Carolina; Urzúa, Marcela; Le Corre, Nicole; Pineda, Augusto; Fernández, Carolina; Domínguez, Angélica; González, Pablo; Bueno, Susan; Donato, Paulina; Espinoza, Pilar; Fuentes, Daniela; González, Marcela; Guzmán, Paula; Muñoz Venturelli, Paula; Pérez, Carlos; Potin, Marcela; Rojas, Álvaro; González, José; Gálvez, Nicolás; Aguirre, Francisca; Aljaro, Sofía; Bátiz, Luis; Campisto, Yessica; Cepeda, Mariela; Cortés, Aarón; López, Sofía; Pérez, María; Schilling, Andrea; Kalergis, Alexis; On behalf of the CoronaVac CL Study GroupSeveral vaccines have been developed to control the COVID-19 pandemic. CoronaVac®, an inactivated SARS-CoV-2 vaccine, has demonstrated safety and immunogenicity, preventing severe COVID-19 cases. We investigate the safety and non-inferiority of two immunization schedules of CoronaVac® in a non-inferiority trial in healthy adults. A total of 2302 healthy adults were enrolled at 8 centers in Chile and randomly assigned to two vaccination schedules, receiving two doses with either 14 or 28 days between each. The primary safety and efficacy endpoints were solicited adverse events (AEs) within 7 days of each dose, and comparing the number of cases of SARS-CoV-2 infection 14 days after the second dose between the schedules, respectively. The most frequent local AE was pain at the injection site, which was less frequent in participants aged ≥60 years. Other local AEs were reported in less than 5% of participants. The most frequent systemic AEs were headache, fatigue, and myalgia. Most AEs were mild and transient. There were no significant differences for local and systemic AEs between schedules. A total of 58 COVID-19 cases were confirmed, and all but 2 of them were mild. No differences were observed in the proportion of COVID-19 cases between schedules. CoronaVac® is safe, especially in ≥60-year-old participants. Both schedules protected against COVID-19 hospitalization.