Publications by authors named "Lafont B"

Article Synopsis
  • The study investigates how inflammatory responses affect pulmonary disease during SARS-CoV-2 infection, specifically using the rhesus macaque model of mild COVID-19.
  • It highlights the contrasting roles of the cytokines IFNγ and IL-10, where IFNγ contributes to lung lesions but isn't necessary for viral replication suppression, while IL-10 reduces inflammation and aids in T cell memory without hindering viral clearance.
  • The research reveals that IL-10 plays a key role in fostering airway memory T cells, indicating its importance in the immune response during SARS-CoV-2 infection.
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Neuroimaging biomarkers are needed to investigate the impact of smoking withdrawal on brain function. NFL-101 is a denicotinized aqueous extract of tobacco leaves currently investigated as an immune-based smoking cessation therapy in humans. However, the immune response to NFL-101 and its ability to induce significant changes in brain function remain to be demonstrated.

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Type-1 and type-3 interferons (IFNs) are important for control of viral replication; however, less is known about the role of Type-2 IFN (IFNγ) in anti-viral immunity. We previously observed that lung infection with Mycobacterium bovis BCG achieved though intravenous (iv) administration provides strong protection against SARS-CoV-2 in mice yet drives low levels of type-1 IFNs but robust IFNγ. Here we examine the role of ongoing IFNγ responses to pre-established bacterial infection on SARS-CoV-2 disease outcomes in two murine models.

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Severe COVID-associated lung injury is a major confounding factor of hospitalizations and death with no effective treatments. Here, we describe a non-classical fibrin clotting mechanism mediated by SARS-CoV-2 infected primary lung but not other susceptible epithelial cells. This infection-induced fibrin formation is observed in all variants of SARS-CoV-2 infections, and requires thrombin but is independent of tissue factor and other classical plasma coagulation factors.

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Helminth endemic regions report lower COVID-19 morbidity and mortality. Here, we show that lung remodeling from a prior infection with a lung-migrating helminth, , enhances viral clearance and survival of human-ACE2 transgenic mice challenged with SARS-CoV-2 (SCV2). This protection is associated with a lymphocytic infiltrate, including increased accumulation of pulmonary SCV2-specific CD8 T cells, and anti-CD8 antibody depletion abrogated the mediated reduction in viral loads.

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The high mortality rate in nursing homes during the COVID-19 pandemic may be linked to psychological disorders in staff. Hence, we assessed the prevalence and associated factors of probable post-traumatic stress disorder (PTSD), anxiety, depression, and burnout of nursing home staff during the COVID-19 pandemic in a cross-sectional study including 66 randomly selected nursing homes in southern France. 537 of the contacted 3 821 nursing home workers (14.

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Helminth endemic regions report lower COVID-19 morbidity and mortality. Here, we show that lung remodeling from a prior infection with a lung migrating helminth, , enhances viral clearance and survival of human-ACE2 transgenic mice challenged with SARS-CoV-2 (SCV2). This protection is associated with a lymphocytic infiltrate including an increased accumulation of pulmonary SCV2-specific CD8+ T cells and anti-CD8 antibody depletion abrogated the -mediated reduction in viral loads.

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Article Synopsis
  • The study investigates how two cytokines, IFNγ and IL-10, influence inflammation and immune responses during SARS-CoV-2 infection in rhesus macaques.
  • Blocking IFNγ reduced lung inflammation without significantly affecting immune cell types, whereas blocking IL-10 increased lung inflammation and the presence of virus-specific T cells but hampered their development into specialized cells.
  • Overall, neither cytokine blockade significantly altered the viral load, indicating that these inflammatory pathways play a minimal role in controlling SARS-CoV-2 replication, though IL-10 is important for regulating T cell responses in the lungs.
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The mosquito protein AEG12 encompasses a large (~ 3800 Å ) hydrophobic cavity which binds and delivers unsaturated fatty acids into biological membranes, allowing it to lyse cells and neutralize a wide range of enveloped viruses. Herein, the lytic and antiviral activities are modified with non-naturally occurring lipid ligands. We generated novel AEG12 complexes in which the endogenous fatty acid ligands were replaced with hydrophobic viral inhibitors.

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Current vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are administered parenterally and appear to be more protective in the lower versus the upper respiratory tract. Vaccines are needed that directly stimulate immunity in the respiratory tract, as well as systemic immunity. We used avian paramyxovirus type 3 (APMV3) as an intranasal vaccine vector to express the SARS-CoV-2 spike (S) protein.

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Article Synopsis
  • SARS-CoV-2 primarily replicates in mucosal sites, and this study used rhesus macaques to investigate the immune responses during mild COVID-19.
  • Viral RNA levels peaked shortly after infection and decreased rapidly, while lung abnormalities and immune cell activation were observed a few days later.
  • T cell responses (CD8 and CD4 T cells) appeared later, indicating that innate immunity may effectively limit the virus's replication before these specific immune cells respond.
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In addition to providing partial protection against pediatric tuberculosis, vaccination with bacille Calmette-Guérin (BCG) has been reported to confer nonspecific resistance to unrelated pulmonary pathogens, a phenomenon attributed to the induction of long-lasting alterations within the myeloid cell compartment. Here, we demonstrate that intravenous, but not subcutaneous, inoculation of BCG protects human-ACE2 transgenic mice against lethal challenge with SARS-CoV-2 (SCV2) and results in reduced viral loads in non-transgenic animals infected with an α variant. The observed increase in host resistance was associated with reductions in SCV2-induced tissue pathology, inflammatory cell recruitment, and cytokine production that multivariate analysis revealed as only partially related to diminished viral load.

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Article Synopsis
  • Single-dose vaccines targeting SARS-CoV-2 are necessary for effective COVID-19 control across all age groups, specifically for infants and children.
  • The study developed a live intranasal vaccine using a chimeric virus that expresses the SARS-CoV-2 spike protein, showing strong immune responses in both hamster models and stable viral replication.
  • Results indicated that the B/HPIV3/S-2P vaccine provided superior protection against SARS-CoV-2, preventing viral replication and associated weight loss in immunized hamsters more effectively than the standard B/HPIV3/S vaccine.
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Early events in the host response to SARS-CoV-2 are thought to play a major role in determining disease severity. During pulmonary infection, the virus encounters both myeloid and epithelioid lineage cells that can either support or restrict pathogen replication as well as respond with host protective versus detrimental mediators. In addition to providing partial protection against pediatric tuberculosis, vaccination with bacille Calmette-Guérin (BCG) has been reported to confer non-specific resistance to unrelated pulmonary pathogens, a phenomenon attributed to the induction of long-lasting alterations within the myeloid cell compartment.

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Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causal agent of COVID-19, uses an RNA-dependent RNA polymerase (RdRp) for the replication of its genome and the transcription of its genes. We found that the catalytic subunit of the RdRp, nsp12, ligates two iron-sulfur metal cofactors in sites that were modeled as zinc centers in the available cryo-electron microscopy structures of the RdRp complex. These metal binding sites are essential for replication and for interaction with the viral helicase.

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Despite signs of infection-including taste loss, dry mouth and mucosal lesions such as ulcerations, enanthema and macules-the involvement of the oral cavity in coronavirus disease 2019 (COVID-19) is poorly understood. To address this, we generated and analyzed two single-cell RNA sequencing datasets of the human minor salivary glands and gingiva (9 samples, 13,824 cells), identifying 50 cell clusters. Using integrated cell normalization and annotation, we classified 34 unique cell subpopulations between glands and gingiva.

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: To demonstrate that a BRASS score≥ 3 at admission of intubated, ventilated and sedated patients is predictive of mortality: we have realized an Observational prospective multicenter study.All Major patients without neurological history, admitted to ICU for a non-neurological cause, sedated and admitted under mechanical ventilation were included.: One hundred and ten patients were included, the BRASS score as well as the FOUR and RASS scores were collected.

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Despite signs of infection, the involvement of the oral cavity in COVID-19 is poorly understood. To address this, single-cell RNA sequencing data-sets were integrated from human minor salivary glands and gingiva to identify 11 epithelial, 7 mesenchymal, and 15 immune cell clusters. Analysis of SARS-CoV-2 viral entry factor expression showed enrichment in epithelia including the ducts and acini of the salivary glands and the suprabasal cells of the mucosae.

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Simian immunodeficiency virus (SIV)-infected nonhuman primates can serve as a relevant model for AIDS neuropathogenesis. Current SIV-induced encephalitis (SIVE)/neurological complications of AIDS (neuroAIDS) models are generally associated with rapid progression to neuroAIDS, which does not reflect the tempo of neuroAIDS progression in humans. Recently, we isolated a neuropathogenic clone, SIVsm804E-CL757 (CL757), obtained from an SIV-infected rhesus macaque (RM).

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The original version of this article contained a spelling error in the Acknowledgments regarding the name of the funding organisation supporting GM and JAH. UKRI-BBSCR should have been UKRI-BBSRC, as is now indicated correctly below.

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The major histocompatibility complex (MHC) is central to the innate and adaptive immune responses of jawed vertebrates. Characteristic of the MHC are high gene density, gene copy number variation, and allelic polymorphism. Because apes and monkeys are the closest living relatives of humans, the MHCs of these non-human primates (NHP) are studied in depth in the context of evolution, biomedicine, and conservation biology.

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Since 1988, France has been committed to drafting laws regulating clinical research. These laws must both reflect general legal standards relating to personal data protection and patient information and comply with EU regulations, which are supra-national norms. The 2012 legislation known as "Jardé law" came into force in 2016 and distinguishes between 3 different types of research involving human subjects: category 1:interventional research implying an intervention on the patient which is not justified by their usual treatment.

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Natural killer (NK) cells recognize and eliminate infected and malignant cells. Their life histories are poorly understood, particularly in humans, due to lack of informative models and endogenous clonal markers. Here, we apply transplantation of barcoded rhesus macaque hematopoietic cells to interrogate the landscape of NK cell production, expansion, and life histories at a clonal level long term and after proliferative challenge.

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