Biology subjects

Garcia-Vilanova, A.

Publications and source records attributed to Garcia-Vilanova, A..

8 recordsLinked to original sources

bioRxiv2025

Identification of protective human monoclonal antibodies using a K18 hACE2 transgenic mouse SARS-CoV-2 challenge model

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), uses human angiotensin converting enzyme 2 (hACE2) as its obligate receptor for cell entry. The K18 hACE2 transgenic mouse line, which expresses hACE2 under control of the human keratin 18 (K18) promoter, is used as an animal model for the study of COVID-19 pathogenesis. Here, we evaluate this model in the screening of human monoclonal antibody (hmAb) therapies against SARS-CoV-2. We included 206 hmAbs from the Coronavirus Immunotherapeutic Consortium Database (CoVIC-DB) and identified many that protected against a lethal challenge with the virus. Our data showed that mouse weight change from day 5 onward highly correlated with survival. Many of the protective hmAb candidates we identified also showed strong viral neutralization and spike protein (SP) binding when measured in vitro; however, in many cases, in vitro assays failed to identify protective hmAbs, suggesting that the mouse model may capture characteristics of the hmAbs that other methods cannot. Our findings demonstrate the relevance of including in vivo models for the characterization of therapeutics against SARS-CoV-2, as these improve both accuracy and expediency in the screening process.

immunology↗

bioRxiv2024

Impact of the elderly lung mucosa on Mycobacterium tuberculosis metabolic adaptation during infection of alveolar epithelial cells

BackgroundTuberculosis (TB) is one of the top leading causes of death due to a single infectious agent. Upon infection, Mycobacterium tuberculosis (M.tb) is deposited in the alveoli and encounters the lung mucosa or alveolar lining fluid (ALF). We previously determined that increased M.tb replication in human macrophages and alveolar epithelial cells (ATs) is mediated by age-associated changes in human ALF. Here we determine the transcriptional profile of M.tb when exposed to healthy ALF from adult (A-ALF) or elderly (E-ALF) individuals before and during infection of ATs. ResultsPrior to infection, exposure to E-ALF upregulates M.tb genes associated with the ESX-4 secretion system, immunomodulatory proteins from the ESX-5 system, and genes encoding phospholipases, phosphatases, and proteases. During infection, E-ALF exposure upregulates key M.tb genes from the ESX-5 secretion system, genes associated with PDIMs biosynthesis and transport, and genes linked to bacterial oxidative stress defense mechanisms. ConclusionsThese findings demonstrate how altered ALF in old age can impact the metabolic status of M.tb, enabling greater adaptation to the host and potentially explaining Mtbs increased survival within host cells. Importantly, we present the first transcriptomic analysis on the impact of the elderly lung mucosa on M.tb pathogenesis during intracellular replication in ATs.

microbiology↗

bioRxiv2024

Mitochondrial Transplantation promotes protective effector and memory CD4+ T cell response during Mycobacterium tuberculosis infection and diminishes exhaustion and senescence in elderly CD4+ T cells

Tuberculosis (TB), caused by the bacterium Mycobacterium tuberculosis (M.tb), remains a significant health concern worldwide, especially in populations with weakened or compromised immune systems, such as the elderly. Proper adaptive immune function, particularly a CD4+ T cell response, is central to host immunity against M.tb. Chronic infections, such as M.tb, as well as aging promote T cell exhaustion and senescence, which can impair immune control and promote progression to TB disease. Mitochondrial dysfunction contributes to T cell dysfunction, both in aging and chronic infections and diseases. Mitochondrial perturbations can disrupt cellular metabolism, enhance oxidative stress, and impair T-cell signaling and effector functions. This study examined the impact of mitochondrial transplantation (mito-transfer) on CD4+ T cell differentiation and function using aged mouse models and human CD4+ T cells from elderly individuals. Our study revealed that mito-transfer in naive CD4+ T cells promoted the generation of protective effector and memory CD4+ T cells during M.tb infection in mice. Further, mito-transfer enhanced the function of elderly human T cells by increasing their mitochondrial mass and modulating cytokine production, which in turn reduced exhaustion and senescence cell markers. Our results suggest that mito-transfer could be a novel strategy to reestablish aged CD4+ T cell function, potentially improving immune responses in the elderly and chronic TB patients, with a broader implication for other diseases where mitochondrial dysfunction is linked to T cell exhaustion and senescence.

immunology↗

bioRxiv2023

HIV Infection impairs the Host Response to Mycobacterium tuberculosis Infection by altering Surfactant Protein D function in the Human Lung Alveolar Mucosa

Tuberculosis is the leading cause of death for people living with HIV (PLWH). We hypothesized that altered functions of innate immune components in the human alveolar lining fluid of PLWH (HIV-ALF), drive susceptibility to Mycobacterium tuberculosis (M.tb) infection. Our results indicate a significant increase in oxidation of innate proteins and chemokine levels, and significantly lower levels and function of complement components and Th1/Th2/Th17 cytokines in HIV-ALF vs. control-ALF (non-HIV infected people). We further found a deficiency of surfactant protein-D (SP-D) and reduced binding of SP-D to M.tb that had been exposed to HIV-ALF. Primary human macrophages infected with M.tb exposed to HIV-ALF were significantly less capable of controlling the infection, which was reversed by SP-D replenishment in HIV-ALF. Thus, our data suggest that PLWH without antiretroviral therapy (ART) have declining host innate defense function in their lung mucosa, thereby favoring M.tb and potentially other pulmonary infections.

cell biology↗

bioRxiv2022

Immunization with recombinant accessory protein-deficient SARS-CoV-2 protects against lethal challenge and viral transmission

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has led to a worldwide Coronavirus Disease 2019 (COVID-19) pandemic. Despite high efficacy of the authorized vaccines, protection against the surging variants of concern (VoC) was less robust. Live-attenuated vaccines (LAV) have been shown to elicit robust and long-term protection by induction of host innate and adaptive immune responses. We sought to develop a COVID-19 LAV by generating 3 double open reading frame (ORF)-deficient recombinant (r)SARS-CoV-2 simultaneously lacking two accessory open reading frame (ORF) proteins (ORF3a/ORF6, ORF3a/ORF7a, and ORF3a/ORF7b). Here, we report that these double ORF-deficient rSARS-CoV-2 have slower replication kinetics and reduced fitness in cultured cells as compared to their parental wild-type (WT) counterpart. Importantly, these double ORF-deficient rSARS-CoV-2 showed attenuation in both K18 hACE2 transgenic mice and golden Syrian hamsters. A single intranasal dose vaccination induced high levels of neutralizing antibodies against different SARS-CoV-2 VoC, and also activated viral component-specific T-cell responses. Notably, the double ORF-deficient rSARS-CoV-2 were able to protect, as determined by inhibition of viral replication, shedding, and transmission, against challenge with SARS-CoV-2. Collectively, our results demonstrate the feasibility to implement these double ORF-deficient rSARS-CoV-2 as safe, stable, immunogenic and protective LAV for the prevention of SARS-CoV-2 infection and associated COVID-19 disease.

microbiology↗

bioRxiv2021

The aging lung mucosa: A proteomics study

The elderly population is at increased risk of acute and chronic respiratory infections and other pulmonary diseases, and it is estimated that this population will double in the next 30 years. Biochemical changes in the lung alveolar mucosa and lung cells alter local immune response as we age, creating opportunities for invading pathogens to establish successful infections. Indeed, the lungs of the elderly are a pro-inflammatory, pro-oxidative, dysregulated environment but this environment has remained understudied. We performed a comprehensive, quantitative proteomic profile of the lung mucosa in the elderly, developing insight into the molecular fingerprints, pathways, and regulatory networks that characterize the lung in old age. We identified neutrophils in the lungs of elderly individuals as possible contributors to dysregulated lung tissue environment. This study establishes a baseline for future investigations to develop strategies to mitigate susceptibility to respiratory infections in the elderly.

systems biology↗

bioRxiv2021

Host- and age-dependent transcriptional changes in Mycobacterium tuberculosis cell envelope biosynthesis genes after exposure to human alveolar lining fluid

Tuberculosis (TB) infection, caused by the airborne pathogen Mycobacterium tuberculosis (M.tb), resulted in almost 1.4 million deaths in 2019 and the number of deaths is predicted to increase by 20% over the next 5 years due to the COVID-19 pandemic. Upon reaching the alveolar space, M.tb comes in close contact with the lung mucosa before and after its encounter with host alveolar compartment cells. Our previous studies show that homeostatic innate soluble components of the alveolar lining fluid (ALF) can quickly alter the cell envelope surface of M.tb upon contact, defining subsequent M.tb-host cell interactions and infection outcomes in vitro and in vivo. We also demonstrated that ALF from 60+ year old elders (E-ALF) vs. healthy 18- to 45-year-old adults (A-ALF) is dysfunctional with loss of homeostatic capacity and impaired innate soluble responses linked to high local oxidative stress. In this study, a targeted transcriptional assay demonstrates that M.tb exposure to human ALF alters the expression of its cell envelope genes. Specifically, our results indicate that A-ALF-exposed M.tb upregulates cell envelope genes associated with lipid, carbohydrate, and amino acid metabolism, as well as genes associated with redox homeostasis and transcriptional regulators. Conversely, M.tb exposure to E-ALF shows lesser transcriptional response, with most of the M.tb genes unchanged or downregulated. Overall, this study indicates that M.tb responds and adapts to the lung alveolar environment upon contact, and that the host ALF status determined by factors such as age might play an important role in determining infection outcome.

molecular biology↗

bioRxiv2021

Human alveolar lining fluid from the elderly promotes Mycobacterium tuberculosis growth in alveolar epithelial cells and bacterial translocation into the cytosol

The elderly population is at significant risk of developing respiratory diseases, including tuberculosis (TB) caused by the airborne Mycobacterium tuberculosis (M.tb). Once M.tb reaches the alveolar space, it contacts alveolar lining fluid (ALF) which dictates host cell interactions. We previously determined that age-associated dysfunctionality in human ALF soluble innate components lead to accelerated M.tb growth within human alveolar macrophages. Here we determined the impact of human ALF on M.tb infection of alveolar epithelial cells (ATs), another critical cellular determinant of infection. We observed that E-ALF-exposed M.tb had significantly increased intracellular growth in ATs compared to adult ALF (A-ALF)-exposed bacteria. Despite this, there were no alterations in AT inflammatory mediators or cell activation. However, exposure to E-ALF altered endosomal trafficking of M.tb, driving bacterial translocation to both endosomal and cytosolic compartments in ATs. Our results indicate that exposure of M.tb to E-ALF promotes translocation of bacteria into the AT cytosol as a potential favorable niche for rapid bacterial growth and at the same time dampens ATs immune responses. Thus, our findings highlight the influence of the elderly lung mucosa on M.tb infection of ATs, an unexplored contributing factor to the elderly populations increased susceptibility of developing active TB disease.

immunology↗