Examinando por Autor "Bohmwald, Karen"
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Ítem BCG-Based Vaccines Elicit Antigen-Specific Adaptive and Trained Immunity against SARS-CoV-2 and Andes orthohantavirus(MDPI, 2022-05) Soto, Jorge A.; Díaz, Fabián E.; Retamal-Díaz, Angello; Gálvez, Nicolás M. S.; Melo-González, Felipe; Piña-Iturbe, Alejandro; Ramírez, Mario A.; Bohmwald, Karen; González, Pablo A.; Bueno, Susan M.; Kalergis, Alexis M.Background: Mycobacterium bovis Bacillus Calmette-Guérin (BCG) is a live attenuated vaccine mainly administered to newborns and used for over 100 years to prevent the disease caused by Mycobacterium tuberculosis (M. tb). This vaccine can induce immune response polarization towards a Th1 profile, which is desired for counteracting M. tb, other mycobacteria, and unrelated intracellular pathogens. The vaccine BCG has been used as a vector to express recombinant proteins and has been shown to protect against several diseases, particularly respiratory viruses. Methods: BCG was used to develop recombinant vaccines expressing either the Nucleoprotein from SARS-CoV-2 or Andes orthohantavirus. Mice were immunized with these vaccines with the aim of evaluating the safety and immunogenicity parameters. Results: Immunization with two doses of 1 × 108 CFU or one dose of 1 × 105 CFU of these BCGs was safe in mice. A statistically significant cellular immune response was induced by both formulations, characterized as the activation of CD4+ and CD8+ T cells. Stimulation with unrelated antigens resulted in increased expression of activation markers by T cells and secretion of IL-2 and IFN-γ, while increased secretion of IL-6 was found for both recombinant vaccines; all of these parameters related to a trained immunity profile. The humoral immune response elicited by both vaccines was modest, but further exposure to antigens could increase this response. Conclusions: The BCG vaccine is a promising platform for developing vaccines against different pathogens, inducing a marked antigen-specific immune response. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.Ítem Characterization of Dendritic Cells and Myeloid-Derived Suppressor Cells Expressing Major Histocompatibility Complex Class II in Secondary Lymphoid Organs in Systemic Lupus Erythematosus-Prone Mice(Multidisciplinary Digital Publishing Institute (MDPI), 2024-12) Uribe, Felipe R.; González-Martínez, Fabián; Echeverría-Araya, Sebastián A.; Sepúlveda-Pontigo, Alison; Chávez-Villacreses, Karissa; Díaz-Bozo, Andrés; Méndez-Pérez, Isabel; González, Valentina P. I.; Bohmwald, Karen; Kalergis, Alexis M.; Soto, Jorge A.Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by self-antibody production and widespread inflammation affecting various body tissues. This disease is driven by the breakdown of immune tolerance, which promotes the activation of autoreactive B and T cells. A key feature of SLE is dysregulation in antigen presentation, where antigen-presenting cells (APCs) play a central role in perpetuating immune responses. Dendritic cells (DCs) are highly specialized for antigen presentation among APCs. At the same time, myeloid-derived suppressor cells (MDSCs) can also express MHC-II molecules, although their role in SLE is less understood. Utilizing the SLE model, MRL/MpJ-Faslpr/J, we determined the presence of different phenotypes of DCs and MDSCs expressing MHC-II in secondary lymphoid organs, along with the gene expression of ICOSL, CD80 and CD86 in the spleen. Our study determined that the most abundant population of APCs in secondary lymphoid organs corresponds to cDC CD103−CD11b+ MHC-II+ throughout SLE development. Additionally, ICOSL expression increased over time, becoming more preponderant in week 16 in the SLE model, which could indicate that it is a crucial pathway for the development and progression of the pathology. In week 16, we observed a positive correlation between M-MDSC MHC-II and IFN-γ-producing CD4+ T cells.Ítem Differential expression profile of CXCR3 splicing variants is associated with thyroid neoplasia. Potential role in papillary thyroid carcinoma oncogenesis?(Impact Journals LLC, 2018) Gamboa, Soledad Urra; Fischer, Martin C.; Martínez, José R.; Véliz, Loreto; Orellana, Paulina; Solar, Antonieta; Bohmwald, Karen; Kalergis, Alexis; Riedel, Claudia; Corvalán, Alejandro H.; Roa, Juan C.; Fuentealba, Rodrigo; Cáceres, C. Joaquín; López-Lastra, Marcelo; León, Augusto; Droppelmann, Nicolás; González, Hernán E.Papillary thyroid cancer (PTC) is the most prevalent endocrine neoplasia. The increased incidence of PTC in patients with thyroiditis and the frequent immune infiltrate found in PTC suggest that inflammation might be a risk factor for PTC development. The CXCR3-ligand system is involved in thyroid inflammation and CXCR3 has been found upregulated in many tumors, suggesting its pro-tumorigenic role under the inflammatory microenvironment. CXCR3 ligands (CXCL4, CXCL9, CXCL10 and CXCL11) trigger antagonistic responses partly due to the presence of two splice variants, CXCR3A and CXCR3B. Whereas CXCR3A promotes cell proliferation, CXCR3B induces apoptosis. However, the relation between CXCR3 variant expression with chronic inflammation and PTC development remains unknown. Here, we characterized the expression pattern of CXCR3 variants and their ligands in benign tumors and PTC. We found that CXCR3A and CXCL10 mRNA levels were increased in non-metastatic PTC when compared to non-neoplastic tissue. This increment was also observed in a PTC epithelial cell line (TPC-1). Although elevated protein levels of both isoforms were detected in benign and malignant tumors, the CXCR3A expression remained greater than CXCR3B and promoted proliferation in Nthy-ori-3-1 cells. In non-metastatic PTC, inflammation was conditioning for the CXCR3 ligands increased availability. Consistently, CXCL10 was strongly induced by interferon gamma in normal and tumor thyrocytes. Our results suggest that persistent inflammation upregulates CXCL10 expression favoring tumor development via enhanced CXCR3A-CXCL10 signaling. These findings may help to further understand the contribution of inflammation as a risk factor in PTC development and set the basis for potential therapeutic studies.Ítem Gestational hypothyroxinemia induces ASD-like phenotypes in behavior, proinflammatory markers, and glutamatergic protein expression in mouse offspring of both sexes(Frontiers Media SA, 2024-04) González-Madrid, Enrique; Rangel-Ramírez, Ma. Andreina; Opazo, María C.; Méndez, Luis; Bohmwald, Karen; Bueno, Susan M.; González, Pablo A.; Kalergis, Alexis M.; Riedel, Claudia A.Background: The prevalence of autism spectrum disorder (ASD) has significantly risen in the past three decades, prompting researchers to explore the potential contributions of environmental factors during pregnancy to ASD development. One such factor of interest is gestational hypothyroxinemia (HTX), a frequent condition in pregnancy associated with cognitive impairments in the offspring. While retrospective human studies have linked gestational HTX to autistic traits, the cellular and molecular mechanisms underlying the development of ASD-like phenotypes remain poorly understood. This study used a mouse model of gestational HTX to evaluate ASD-like phenotypes in the offspring. Methods: To induce gestational HTX, pregnant mice were treated with 2-mercapto-1-methylimidazole (MMI), a thyroid hormones synthesis inhibitor, in the tap-drinking water from embryonic days (E) 10 to E14. A separate group received MMI along with a daily subcutaneous injection of T4, while the control group received regular tap water during the entire pregnancy. Female and male offspring underwent assessments for repetitive, anxious, and social behaviors from postnatal day (P) 55 to P64. On P65, mice were euthanized for the evaluation of ASD-related inflammatory markers in blood, spleen, and specific brain regions. Additionally, the expression of glutamatergic proteins (NLGN3 and HOMER1) was analyzed in the prefrontal cortex and hippocampus. Results: The HTX-offspring exhibited anxious-like behavior, a subordinate state, and impaired social interactions. Subsequently, both female and male HTX-offspring displayed elevated proinflammatory cytokines in blood, including IL-1β, IL-6, IL-17A, and TNF-α, while only males showed reduced levels of IL-10. The spleen of HTX-offspring of both sexes showed increased Th17/Treg ratio and M1-like macrophages. In the prefrontal cortex and hippocampus of male HTX-offspring, elevated levels of IL-17A and reduced IL-10 were observed, accompanied by increased expression of hippocampal NLGN3 and HOMER1. All these observations were compared to those observed in the Control-offspring. Notably, the supplementation with T4 during the MMI treatment prevents the development of the observed phenotypes. Correlation analysis revealed an association between maternal T4 levels and specific ASD-like outcomes. Discussion: This study validates human observations, demonstrating for the first time that gestational HTX induces ASD-like phenotypes in the offspring, highlighting the need of monitoring thyroid function during pregnancy.Ítem Modulation of host adaptive immunity by hRSV proteins(Landes Bioscience, 2014) Espinoza, Janyra A.; Bohmwald, Karen; Céspedes, Pablo F.; Céspedes, Pablo F.; Bueno, Susan M.; Kalergis, Alexis M.Globally, the human respiratory syncytial virus (hRSV) is the major cause of lower respiratory tract infections (LRTIs) in infants and children younger than 2 years old. Furthermore, the number of hospitalizations due to LRTIs has shown a sus tained increase every year due to the lack of effective vaccines against hRSV. Thus, this virus remains as a major public health and economic burden worldwide. The lung pathology devel oped in hRSV-infected humans is characterized by an exac erbated inflammatory and Th2 immune response. In order to rationally design new vaccines and therapies against this virus, several studies have focused in elucidating the interac tions between hRSV virulence factors and the host immune system. Here, we discuss the main features of hRSV biology, the processes involved in virus recognition by the immune system and the most relevant mechanisms used by this patho gen to avoid the antiviral host response.Ítem Pathophysiological, immunological, and inflammatory features of long COVID(Frontiers Media SA, 2024) Bohmwald, Karen; Diethelm-Varela, Benjamín; Rodríguez-Guilarte, Linmar; Rivera, Thomas; Riedel, Claudia A.; González, Pablo A.; Kalergis, Alexis M.The COVID-19 pandemic continues to cause severe global disruption, resulting in significant excess mortality, overwhelming healthcare systems, and imposing substantial social and economic burdens on nations. While most of the attention and therapeutic efforts have concentrated on the acute phase of the disease, a notable proportion of survivors experience persistent symptoms post-infection clearance. This diverse set of symptoms, loosely categorized as long COVID, presents a potential additional public health crisis. It is estimated that 1 in 5 COVID-19 survivors exhibit clinical manifestations consistent with long COVID. Despite this prevalence, the mechanisms and pathophysiology of long COVID remain poorly understood. Alarmingly, evidence suggests that a significant proportion of cases within this clinical condition develop debilitating or disabling symptoms. Hence, urgent priority should be given to further studies on this condition to equip global public health systems for its management. This review provides an overview of available information on this emerging clinical condition, focusing on the affected individuals’ epidemiology, pathophysiological mechanisms, and immunological and inflammatory profiles.Ítem Transient gestational hypothyroxinemia accelerates and enhances ulcerative colitis-like disorder in the male offspring(Frontiers Media SA, 2024-01) Rivera, Juan Carlos; Opazo, Ma. Cecilia; Hernández-Armengol, Rosario; Álvarez, Oscar; Mendoza-León, María José; Caamaño, Esteban; Gatica, Sebastian; Bohmwald, Karen; Bueno, Susan M.; González, Pablo A.; Neunlist, Michel f; Boudin, Helene fIntroduction: Gestational hypothyroxinemia (HTX) is a condition that occurs frequently at the beginning of pregnancy, and it correlates with cognitive impairment, autism, and attentional deficit in the offspring. Evidence in animal models suggests that gestational HTX can increase the susceptibility of the offspring to develop strong inflammation in immune-mediated inflammatory diseases. Ulcerative colitis (UC) is a frequent inflammatory bowel disease with unknown causes. Therefore, the intensity of ulcerative colitis-like disorder (UCLD) and the cellular and molecular factors involved in proinflammatory or anti-inflammatory responses were analyzed in the offspring gestated in HTX (HTX-offspring) and compared with the offspring gestated in euthyroidism (Control-offspring). Methods: Gestational HTX was induced by the administration of 2-mercapto-1- methylimidazole in drinking water to pregnant mice during E10–E14. The HTXoffspring were induced with UCLD by the acute administration of dextran sodium sulfate (DSS). The score of UCLD symptomatology was registered every day, and colon histopathology, immune cells, and molecular factors involved in the inflammatory or anti-inflammatory response were analyzed on day 6 of DSS treatment. Results: The HTX-offspring displayed earlier UCLD pathological symptoms compared with the Control-offspring. After 6 days of DSS treatment, the HTXoffspring almost doubled the score of the Control-offspring. The histopathological analyses of the colon samples showed signs of inflammationÍtem Transient gestational hypothyroxinemia accelerates and enhances ulcerative colitis-like disorder in the male offspring(Frontiers Media SA, 0024) Rivera, Juan Carlos; Opazo, Ma. Cecilia; Hernández-Armengol, Rosario; Álvarez, Oscar; Mendoza-León, María José; Caamaño, Esteban; Gatica, Sebastian; Bohmwald, Karen; Bueno, Susan M.; González, Pablo A.; Neunlist, Michel; Boudin, HeleneIntroduction: Gestational hypothyroxinemia (HTX) is a condition that occurs frequently at the beginning of pregnancy, and it correlates with cognitive impairment, autism, and attentional deficit in the offspring. Evidence in animal models suggests that gestational HTX can increase the susceptibility of the offspring to develop strong inflammation in immune-mediated inflammatory diseases. Ulcerative colitis (UC) is a frequent inflammatory bowel disease with unknown causes. Therefore, the intensity of ulcerative colitis-like disorder (UCLD) and the cellular and molecular factors involved in proinflammatory or anti-inflammatory responses were analyzed in the offspring gestated in HTX (HTX-offspring) and compared with the offspring gestated in euthyroidism (Control-offspring). Methods: Gestational HTX was induced by the administration of 2-mercapto-1-methylimidazole in drinking water to pregnant mice during E10–E14. The HTX-offspring were induced with UCLD by the acute administration of dextran sodium sulfate (DSS). The score of UCLD symptomatology was registered every day, and colon histopathology, immune cells, and molecular factors involved in the inflammatory or anti-inflammatory response were analyzed on day 6 of DSS treatment. Results: The HTX-offspring displayed earlier UCLD pathological symptoms compared with the Control-offspring. After 6 days of DSS treatment, the HTX-offspring almost doubled the score of the Control-offspring. The histopathological analyses of the colon samples showed signs of inflammation at the distal and medial colon for both the HTX-offspring and Control-offspring. However, significantly more inflammatory features were detected in the proximal colon of the HTX-offspring induced with UCLD compared with the Control-offspring induced with UCLD. Significantly reduced mRNA contents encoding for protective molecules like glutamate-cysteine ligase catalytic subunit (GCLC) and mucin-2 (MUC-2) were found in the colon of the HTX-offspring as compared with the Control-offspring. Higher percentages of Th17 lymphocytes were detected in the colon tissues of the HTX-offspring induced or not with UCLD as compared with the Control-offspring. Discussion: Gestational HTX accelerates the onset and increases the intensity of UCLD in the offspring. The low expression of MUC-2 and GCLC together with high levels of Th17 Lymphocytes in the colon tissue suggests that the HTX-offspring has molecular and cellular features that favor inflammation and tissue damage. These results are important evidence to be aware of the impact of gestational HTX as a risk factor for UCLD development in offspring. Copyright © 2024 Rivera, Opazo, Hernández-Armengol, Álvarez, Mendoza-León, Caamaño, Gatica, Bohmwald, Bueno, González, Neunlist, Boudin, Kalergis and Riedel.Ítem Understanding the Neurotrophic Virus Mechanisms and Their Potential Effect on Systemic Lupus Erythematosus Development(MDPI, 2024-01-01) Uribe, Felipe R.; González, Valentina P. I.; Kalergis, Alexis M.; Soto, Jorge A.; Bohmwald, KarenCentral nervous system (CNS) pathologies are a public health concern, with viral infections one of their principal causes. These viruses are known as neurotropic pathogens, characterized by their ability to infiltrate the CNS and thus interact with various cell populations, inducing several diseases. The immune response elicited by neurotropic viruses in the CNS is commanded mainly by microglia, which, together with other local cells, can secrete inflammatory cytokines to fight the infection. The most relevant neurotropic viruses are adenovirus (AdV), cytomegalovirus (CMV), enterovirus (EV), Epstein–Barr Virus (EBV), herpes simplex virus type 1 (HSV-1), and herpes simplex virus type 2 (HSV-2), lymphocytic choriomeningitis virus (LCMV), and the newly discovered SARS-CoV-2. Several studies have associated a viral infection with systemic lupus erythematosus (SLE) and neuropsychiatric lupus (NPSLE) manifestations. This article will review the knowledge about viral infections, CNS pathologies, and the immune response against them. Also, it allows us to understand the relevance of the different viral proteins in developing neuronal pathologies, SLE and NPSLE.