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Journal of Visualized Experiments : JoVE May 2024We introduce an advanced immunocompetent lung-on-chip model designed to replicate the human alveolar structure and function. This innovative model employs a...
We introduce an advanced immunocompetent lung-on-chip model designed to replicate the human alveolar structure and function. This innovative model employs a microfluidic-perfused biochip that supports an air-liquid interface mimicking the environment in the human alveoli. Tissue engineering is used to integrate key cellular components, including endothelial cells, macrophages, and epithelial cells, to create a representative tissue model of the alveolus. The model facilitates in-depth examinations of the mucosal immune responses to various pathogens, including viruses, bacteria, and fungi, thereby advancing our understanding of lung immunity. The primary goal of this protocol is to provide details for establishing this alveolus-on-chip model as a robust in vitro platform for infection studies, enabling researchers to closely observe and analyze the complex interactions between pathogens and the host's immune system within the pulmonary environment. This is achieved through the application of microfluidic-based techniques to simulate key physiological conditions of the human alveoli, including blood flow and biomechanical stimulation of endothelial cells, alongside maintaining an air-liquid interface crucial for the realistic exposure of epithelial cells to air. The model system is compatible with a range of standardized assays, such as immunofluorescence staining, cytokine profiling, and colony-forming unit (CFU)/plaque analysis, allowing for comprehensive insights into immune dynamics during infection. The Alveolus-on-chip is composed of essential cell types, including human distal lung epithelial cells (H441) and human umbilical vein endothelial cells (HUVECs) separated by porous polyethylene terephthalate (PET) membranes, with primary monocyte-derived macrophages strategically positioned between the epithelial and endothelial layers. The tissue model enhances the ability to dissect and analyze the nuanced factors involved in pulmonary immune responses in vitro. As a valuable tool, it should contribute to the advancement of lung research, providing a more accurate and dynamic in vitro model for studying the pathogenesis of respiratory infections and testing potential therapeutic interventions.
Topics: Humans; Pulmonary Alveoli; Lab-On-A-Chip Devices; Immunity, Mucosal; Microfluidic Analytical Techniques
PubMed: 38884475
DOI: 10.3791/66602 -
Frontiers in Microbiology 2024Infection with SARS-CoV-2 begins in the upper respiratory tract and can trigger the production of mucosal spike-specific secretory IgA (sIgA), which provides protection...
INTRODUCTION
Infection with SARS-CoV-2 begins in the upper respiratory tract and can trigger the production of mucosal spike-specific secretory IgA (sIgA), which provides protection against reinfection. It has been recognized that individuals with high level of nasal spike-specific IgA have a lower risk of reinfection. However, mucosal spike-specific sIgA wanes over time, and different individuals may have various level of spike-specific sIgA and descending kinetics, leading to individual differences in susceptibility to reinfection. A method for detecting spike-specific sIgA in the nasal passage would be valuable for predicting the risk of reinfection so that people at risk can have better preparedness.
METHODS
In this study, we describe the development of a colloidal gold-based immunochromatographic (ICT) strip for detecting SARS-CoV-2 Omicron spike-specific sIgA in nasal mucosal lining fluids (NMLFs).
RESULTS
The ICT strip was designed to detect 0.125 μg or more spike-specific sIgA in 80 μL of NMLFs collected using a nasal swab. Purified nasal sIgA samples from individuals who recently recovered from an Omicron BA.5 infection were used to demonstrate that this ICT strip can specifically detect spike-specific sIgA. The signal levels positively correlated with neutralizing activities against XBB. Subsequent analysis revealed that people with low or undetectable levels of spike-specific sIgA in the nasal passage were more susceptible to SARS-CoV-2 reinfection.
CONCLUSIONS
This nasal spike-specific sIgA ICT strip provides a non-invasive, rapid, and convenient method to assess the risk of reinfection for achieving precision preparedness.
PubMed: 38881666
DOI: 10.3389/fmicb.2024.1386891 -
Human Vaccines & Immunotherapeutics Dec 2024Mucosal immunity plays a crucial role in combating and controlling the spread of highly mutated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Recombinant...
Mucosal immunity plays a crucial role in combating and controlling the spread of highly mutated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Recombinant subunit vaccines have shown safety and efficacy in clinical trials, but further investigation is necessary to evaluate their feasibility as mucosal vaccines. This study developed a SARS-CoV-2 mucosal vaccine using spike (S) proteins from a prototype strain and the omicron variant, along with a cationic chitosan adjuvant, and systematically evaluated its immunogenicity after both primary and booster immunization in mice. Primary immunization through intraperitoneal and intranasal administration of the S protein elicited cross-reactive antibodies against prototype strains, as well as delta and omicron variants, with particularly strong effects observed after mucosal vaccination. In the context of booster immunization following primary immunization with inactivated vaccines, the omicron-based S protein mucosal vaccine resulted in a broader and more robust neutralizing antibody response in both serum and respiratory mucosa compared to the prototype vaccine, enhancing protection against different variants. These findings indicate that mucosal vaccination with the S protein has the potential to trigger a broader and stronger antibody response during primary and booster immunization, making it a promising strategy against respiratory pathogens.
Topics: Animals; Spike Glycoprotein, Coronavirus; Administration, Intranasal; Mice; Immunization, Secondary; COVID-19 Vaccines; Antibodies, Neutralizing; Antibodies, Viral; SARS-CoV-2; COVID-19; Mice, Inbred BALB C; Female; Immunity, Mucosal; Immunogenicity, Vaccine; Cross Reactions; Chitosan; Adjuvants, Vaccine; Vaccines, Inactivated
PubMed: 38880868
DOI: 10.1080/21645515.2024.2364519 -
Journal of Equine Veterinary Science Jun 2024The neonatal Fc receptor (FcRn) is the receptor responsible for bidirectional transport of immunoglobulin G (IgG) across cells, maintenance of IgG levels in serum, and...
The neonatal Fc receptor (FcRn) is the receptor responsible for bidirectional transport of immunoglobulin G (IgG) across cells, maintenance of IgG levels in serum, and assisting with antigen presentation. Unfortunately, little is known about FcRn in horses. Therefore, the objective of this study was to provide fundamental information regarding the location of FcRn in equine tissues. Tissues were collected from six horses of mixed breed, age, and sex immediately following euthanasia. Sampling locations included the respiratory tract, gastrointestinal tract (GIT), other visceral organs, cornea, and synovial membrane of the stifle and carpal joints. Tissues for histological analysis were fixed, cross sectioned, and stained for FcRn. Areas of interest were captured and analyzed with data represented as relative fluorescence (RF) to indicate FcRn abundance. Tissues for qPCR analysis were placed in RNAlater and relative quantification (RQ) of FcRn transcripts (FCGRT) was calculated using the 2 method, normalized to the geometric mean of three reference genes (ACTB, GADPH, HPRT1). Data were analyzed using the general linear model procedure of SAS. Abundance of FcRn differed between tissue types by immunofluorescence and qPCR analysis (P < 0.01). Joint synovium and respiratory tract tissues had the highest RF, GIT tissues expressed moderate RF, and other visceral organs had the lowest RF. Conversely, liver and kidney tissues had the highest RQ while the stomach and cornea had the lowest RQ. These data lay the foundation for future studies regarding FcRn and IgG in horses and their roles in disease prevention and treatment.
PubMed: 38879095
DOI: 10.1016/j.jevs.2024.105131 -
International Immunopharmacology Jun 2024Selenium nanoparticles (SeNPs) enhance the immune response as adjuvants, increasing the efficacy of viral vaccines, including those for COVID-19. However, the efficiency...
Selenium nanoparticles (SeNPs) enhance the immune response as adjuvants, increasing the efficacy of viral vaccines, including those for COVID-19. However, the efficiency of mucosal SeNPs in boosting vaccine-induced protective immunity against tuberculosis remains unclear. Therefore, this study aims to investigate whether the combination of SeNPs with the AH antigen (Ag85A-HspX) can boost respiratory mucosal immunity and thereby enhance the protective effects against tuberculosis. We synthesized SeNPs and assessed their impact on the immune response and protection against Mycobacterium bovis (M. bovis) as a mucosal adjuvant in mice, administered intranasally at a dose of 20 µg. SeNPs outperformed polyinosinic-polycytidylic acid (Poly IC) in stimulating the maturation of bone marrow-derived dendritic cells (BMDCs), which enhanced antigen presentation. SeNPs significantly activated and proliferated tissue-resident memory T cells (T) and effector CD4 T cells in the lungs. The vaccines elicited specific antibody responses in the respiratory tract and stimulated systemic Th1 and Th17 immune responses. Immunization with AH and SeNPs led to higher levels of mucosal secretory IgA in bronchoalveolar lavage fluid (BALF) and secretory IL-17 in splenocytes. Moreover, SeNPs immunized mice showed reduced M. bovis infection loads and inflammatory lesions in the lungs post-challenge. Notably, immunization with AH and SeNPs significantly reduced bacterial load in the lungs, achieving the lowest levels compared to all other tested groups. This study calls for pre-clinical investigation of AHB-SeNPs as an anti-bovine tuberculosis vaccine and for exploring its human vaccine potential, which is anticipated to aid in the development of innovative vaccines or adjuvants.
PubMed: 38878484
DOI: 10.1016/j.intimp.2024.112384 -
Scientific Reports Jun 2024Adjuvants enhance, prolong, and modulate immune responses by vaccine antigens to maximize protective immunity and enable more effective immunization in the young and...
Adjuvants enhance, prolong, and modulate immune responses by vaccine antigens to maximize protective immunity and enable more effective immunization in the young and elderly. Most adjuvants are formulated with injectable vaccines. However, an intranasal route of vaccination may induce mucosal and systemic immune responses for enhancing protective immunity in individuals and be easier to administer compared to injectable vaccines. In this study, a next generation of broadly-reactive influenza hemagglutinin (HA) vaccines were developed using the Computationally Optimized Broadly Reactive Antigen (COBRA) methodology. These HA vaccines were formulated with Mastoparan 7 (M7-NH) mast cell degranulating peptide adjuvant and administered intranasally to determine vaccine-induced seroconversion of antibodies against a panel of influenza viruses and protection following infection with H1N1 and H3N2 viruses in mice. Mice vaccinated intranasally with M7-NH-adjuvanted COBRA HA vaccines had high HAIs against a panel of H1N1 and H3N2 influenza viruses and were protected against both morbidity and mortality, with reduced viral lung titers, following challenge with an H1N1 influenza virus. Additionally, M7-NH adjuvanted COBRA HA vaccines induced Th2 skewed immune responses with robust IgG and isotype antibodies in the serum and mucosal lung lavages. Overall, this intranasally delivered M7-NH -adjuvanted COBRA HA vaccine provides effective protection against drifted H1N1 and H3N2 viruses.
Topics: Influenza Vaccines; Animals; Mice; Hemagglutinin Glycoproteins, Influenza Virus; Influenza A Virus, H1N1 Subtype; Influenza A Virus, H3N2 Subtype; Adjuvants, Immunologic; Antibodies, Viral; Orthomyxoviridae Infections; Administration, Intranasal; Female; Mice, Inbred BALB C; Intercellular Signaling Peptides and Proteins; Adjuvants, Vaccine
PubMed: 38877101
DOI: 10.1038/s41598-024-64351-7 -
Life Science Alliance Sep 2024Innate lymphoid cells (ILCs) are critical for intestinal adaptation to microenvironmental challenges, and the gut mucosa is characterized by low oxygen. Adaptation to...
Innate lymphoid cells (ILCs) are critical for intestinal adaptation to microenvironmental challenges, and the gut mucosa is characterized by low oxygen. Adaptation to low oxygen is mediated by hypoxia-inducible transcription factors (HIFs), and the HIF-1α subunit shapes an ILC phenotype upon acute colitis that contributes to intestinal damage. However, the impact of HIF signaling in NKp46 ILCs in the context of repetitive mucosal damage and chronic inflammation, as it typically occurs during inflammatory bowel disease, is unknown. In chronic colitis, mice lacking the HIF-1α isoform in NKp46+ ILCs show a decrease in NKp46 ILC1s but a concomitant rise in neutrophils and Ly6C macrophages. Single-nucleus RNA sequencing suggests enhanced interaction of mesenchymal cells with other cell compartments in the colon of HIF-1α KO mice and a loss of mucus-producing enterocytes and intestinal stem cells. This was, furthermore, associated with increased bone morphogenetic pathway-integrin signaling, expansion of fibroblast subsets, and intestinal fibrosis. In summary, this suggests that HIF-1α-mediated ILC1 activation, although detrimental upon acute colitis, protects against excessive inflammation and fibrosis during chronic intestinal damage.
Topics: Animals; Hypoxia-Inducible Factor 1, alpha Subunit; Natural Cytotoxicity Triggering Receptor 1; Mice; Colitis; Fibrosis; Mice, Knockout; Lymphocytes; Intestinal Mucosa; Inflammation; Mice, Inbred C57BL; Chronic Disease; Immunity, Innate; Signal Transduction; Disease Models, Animal; Male; Intestines; Antigens, Ly
PubMed: 38876796
DOI: 10.26508/lsa.202402593 -
Current Opinion in Immunology Jun 2024Gasdermins are membrane pore-forming proteins that cause pyroptosis, an inflammatory cell death in which cells burst and release cytokines, chemokines, and other host... (Review)
Review
Gasdermins are membrane pore-forming proteins that cause pyroptosis, an inflammatory cell death in which cells burst and release cytokines, chemokines, and other host alarm signals, such as ATP and HMGB1, which recruit and activate immune cells at sites of infection and danger. There are five gasdermins in humans - gasdermins A to E. Pyroptosis was first described in myeloid cells and mucosal epithelia, which express gasdermin D and activate it when cytosolic sensors of invasive infection or tissue damage assemble into large macromolecular structures, called inflammasomes. Inflammasomes recruit and activate inflammatory caspases (caspase 1, 4, 5, and 11), which cut gasdermin D to remove an inhibitory C-terminal domain, allowing the N-terminal domain to bind to membrane acidic lipids and oligomerize into pores. Recent studies have identified inflammasome-independent proteolytic pathways that activate gasdermin D and the other gasdermins. Here, we review inflammasome-independent pyroptosis pathways and what is known about their role in normal physiology and disease.
PubMed: 38875738
DOI: 10.1016/j.coi.2024.102432 -
Journal of Virology Jun 2024The reoccurrence of successive waves of SARS-CoV-2 variants suggests the exploration of more vaccine alternatives is imperative. Modified vaccinia virus Ankara (MVA) is...
UNLABELLED
The reoccurrence of successive waves of SARS-CoV-2 variants suggests the exploration of more vaccine alternatives is imperative. Modified vaccinia virus Ankara (MVA) is a virus vector exhibiting excellent safety as well as efficacy for vaccine development. Here, a series of recombinant MVAs (rMVAs) expressing monomerized or trimerized S proteins from different SARS-CoV-2 variants are engineered. Trimerized S expressed from rMVAs is found predominantly as trimers on the surface of infected cells. Remarkably, immunization of mice with rMVAs demonstrates that S expressed in trimer elicits higher levels of binding IgG and IgA, as well as neutralizing antibodies for matched and mismatched S proteins than S in the monomer. In addition, trimerized S expressed by rMVA induces enhanced cytotoxic T-cell responses than S in the monomer. Importantly, the rMVA vaccines expressing trimerized S exhibit superior protection against a lethal SARS-CoV-2 challenge as the immunized animals all survive without displaying any pathological conditions. This study suggests that opting for trimerized S may represent a more effective approach and highlights that the MVA platform serves as an ideal foundation to continuously advance SARS-CoV-2 vaccine development.
IMPORTANCE
MVA is a promising vaccine vector and has been approved as a vaccine for smallpox and mpox. Our analyses suggested that recombinant MVA expressing S in trimer (rMVA-ST) elicited robust cellular and humoral immunity and was more effective than MVA-S-monomer. Importantly, the rMVA-ST vaccine was able to stimulate decent cross-reactive neutralization against pseudoviruses packaged using S from different sublineages, including Wuhan, Delta, and Omicron. Remarkably, mice immunized with rMVA-ST were completely protected from a lethal challenge of SARS-CoV-2 without displaying any pathological conditions. Our results demonstrated that an MVA vectored vaccine expressing trimerized S is a promising vaccine candidate for SARS-CoV-2 and the strategy might be adapted for future vaccine development for coronaviruses.
PubMed: 38874361
DOI: 10.1128/jvi.00521-24 -
International Journal of Reproductive... Mar 2023Endometriosis is a chronic estrogen-related inflammatory disorder that is known by proliferating endometrial cells in a place outside the uterus. The high presence of...
Human V 7.2-J 33 mucosal-associated invariant T cells in endometrial ectopic tissues tend to produce interferon-gamma: A new player in endometriosis etiology: A case-control study.
BACKGROUND
Endometriosis is a chronic estrogen-related inflammatory disorder that is known by proliferating endometrial cells in a place outside the uterus. The high presence of immune cells in the peritoneal fluid of women with endometriosis confirms the involvement of the immune system in the pathogenesis of the disease. Mucosal-associated invariant T (MAIT) cells play an undeniable impact on mucosal immunity by the production of interleukin-17, interferon-gamma (IFN-γ), and tumor necrosis factor-alpha. The function of the cells in the pathogenesis of endometriosis is less investigated.
OBJECTIVE
This study aims to investigate the infiltration of MAIT cells by using the determination levels of gene expression in eutopic and ectopic tissue of endometriosis lesions.
MATERIALS AND METHODS
In this case-control study, the tested samples include 20 eutopic and 20 ectopic tissues of women with endometriosis and 20 uterine endometrial tissues of women in the control group. Expressions of the tumor necrosis factor-alpha, interleukin-17A, and -γ genes were analyzed by quantitative reverse transcriptase-polymerase chain reaction.
RESULTS
According to the results, gene expression did not show substantial elevation in the uterine and eutopic endometrial tissues compared to internal gene control as well as in ectopic tissues. Correlation analysis approved a positive relationship between expression genes and -γ levels in ectopic tissues.
CONCLUSION
Considering the low-expression specific gene of MAIT cells in ectopic tissue, it can be concluded that these cells are present in the endometriotic environment to a certain extent, and there is a possibility of their role in the progression of endometriosis by secreting IFN- .
PubMed: 38868448
DOI: 10.18502/ijrm.v22i3.16168