scholarly journals Primary and Memory Response of Human Monocytes to Vaccines: Role of Nanoparticulate Antigens in Inducing Innate Memory

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 931
Author(s):  
Mayra M. Ferrari Ferrari Barbosa ◽  
Alex Issamu Kanno ◽  
Leonardo Paiva Farias ◽  
Mariusz Madej ◽  
Gergö Sipos ◽  
...  
Keyword(s):  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Innate Immune ◽  
Soluble Form ◽  
Neisseria Lactamica ◽  
Particulate Form ◽  
Future Challenges ◽  
Monocytes And Macrophages

Innate immune cells such as monocytes and macrophages are activated in response to microbial and other challenges and mount an inflammatory defensive response. Exposed cells develop the so-called innate memory, which allows them to react differently to a subsequent challenge, aiming at better protection. In this study, using human primary monocytes in vitro, we have assessed the memory-inducing capacity of two antigenic molecules of Schistosoma mansoni in soluble form compared to the same molecules coupled to outer membrane vesicles of Neisseria lactamica. The results show that particulate challenges are much more efficient than soluble molecules in inducing innate memory, which is measured as the production of inflammatory and anti-inflammatory cytokines (TNFα, IL-6, IL-10). Controls run with LPS from Klebsiella pneumoniae compared to the whole bacteria show that while LPS alone has strong memory-inducing capacity, the entire bacteria are more efficient. These data suggest that microbial antigens that are unable to induce innate immune activation can nevertheless participate in innate activation and memory when in a particulate form, which is a notion that supports the use of nanoparticulate antigens in vaccination strategies for achieving adjuvant-like effects of innate activation as well as priming for improved reactivity to future challenges.

Characterization and pathogenic role of outer membrane vesicles produced by the fish pathogen Piscirickettsia salmonis under in vitro conditions

2016 ◽  
Vol 184 ◽  
pp. 94-101 ◽  
Author(s):  
Cristian Oliver ◽  
Karla Valenzuela ◽  
Mauricio Hernández ◽  
Rodrigo Sandoval ◽  
Ronie E. Haro ◽  
...  
Keyword(s):  
Outer Membrane ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Fish Pathogen ◽  
Pathogenic Role ◽  
Piscirickettsia Salmonis

scholarly journals Membrane Vesicle Release in Bacteria, Eukaryotes, and Archaea: a Conserved yet Underappreciated Aspect of Microbial Life

2012 ◽  
Vol 80 (6) ◽  
pp. 1948-1957 ◽  
Author(s):  
Brooke L. Deatherage ◽  
Brad T. Cookson
Keyword(s):  
Membrane Vesicle ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Host Immune System ◽  
Vesicle Release ◽  
Communication Signals ◽  
Microbial Life ◽  
Functional Features

ABSTRACTInteraction of microbes with their environment depends on features of the dynamic microbial surface throughout cell growth and division. Surface modifications, whether used to acquire nutrients, defend against other microbes, or resist the pressures of a host immune system, facilitate adaptation to unique surroundings. The release of bioactive membrane vesicles (MVs) from the cell surface is conserved across microbial life, in bacteria, archaea, fungi, and parasites. MV production occurs not onlyin vitrobut alsoin vivoduring infection, underscoring the influence of these surface organelles in microbial physiology and pathogenesis through delivery of enzymes, toxins, communication signals, and antigens recognized by the innate and adaptive immune systems. Derived from a variety of organisms that span kingdoms of life and called by several names (membrane vesicles, outer membrane vesicles [OMVs], exosomes, shedding microvesicles, etc.), the conserved functions and mechanistic strategies of MV release are similar, including the use of ESCRT proteins and ESCRT protein homologues to facilitate these processes in archaea and eukaryotic microbes. Although forms of MV release by different organisms share similar visual, mechanistic, and functional features, there has been little comparison across microbial life. This underappreciated conservation of vesicle release, and the resulting functional impact throughout the tree of life, explored in this review, stresses the importance of vesicle-mediated processes throughout biology.

scholarly journals The Hepatitis C Virus-Induced Membranous Web in Liver Tissue

Cells ◽  
2018 ◽  
Vol 7 (11) ◽  
pp. 191
Author(s):  
Emmanuelle Blanchard ◽  
Philippe Roingeard
Keyword(s):  
Immune Response ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Innate Immune Response ◽  
Liver Tissue ◽  
Hepatoma Cell ◽  
Membrane Vesicles ◽  
Innate Immune ◽  
Host Cell Membrane

Host cell membrane rearrangements induced by the hepatitis C virus (HCV) have been exclusively studied in vitro. These studies have shown that HCV induces double-membrane vesicles (DMVs), which probably serve to separate replication sites from the cytoplasmic sensors of the innate immune response. We report for the first time the observation of HCV-induced membrane rearrangements in liver biopsy specimens from patients chronically infected with HCV. Unlike observations performed in vitro, the membranous web detected in liver tissue seems essentially made of clusters of single-membrane vesicles derived from the endoplasmic reticulum and close to lipid droplets. This suggests that the DMVs could be a hallmark of laboratory-adapted HCV strains, possibly due to their ability to achieve a high level of replication. Alternatively, the concealment of viral RNA in DMVs may be part of innate immune response mechanisms particularly developed in hepatoma cell lines cultured in vitro. In any case, this constitutes the first report showing the differences in the membranous web established by HCV in vitro and in vivo.

In vitro study of virulence potential of Acinetobacter baumannii outer membrane vesicles

2017 ◽  
Vol 111 ◽  
pp. 218-224 ◽  
Author(s):  
Chandana Jha ◽  
Sujata Ghosh ◽  
Vikas Gautam ◽  
Pankaj Malhotra ◽  
Pallab Ray
Keyword(s):  
Acinetobacter Baumannii ◽  
Outer Membrane ◽  
In Vitro Study ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Vitro Study ◽  
Virulence Potential

scholarly journals ADAR1 function affects HPV replication and is associated to recurrent human papillomavirus-induced dysplasia in HIV coinfected individuals

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Maria Pujantell ◽  
Roger Badia ◽  
Iván Galván-Femenía ◽  
Edurne Garcia-Vidal ◽  
Rafael de Cid ◽  
...  
Keyword(s):  
Human Papillomavirus ◽  
Immune Activation ◽  
Hpv Infection ◽  
Innate Immune ◽  
Type I ◽  
Innate Immune Activation ◽  
Enhanced Expression

AbstractInfection by human papillomavirus (HPV) alters the microenvironment of keratinocytes as a mechanism to evade the immune system. A-to-I editing by ADAR1 has been reported to regulate innate immunity in response to viral infections. Here, we evaluated the role of ADAR1 in HPV infection in vitro and in vivo. Innate immune activation was characterized in human keratinocyte cell lines constitutively infected or not with HPV. ADAR1 knockdown induced an innate immune response through enhanced expression of RIG-I-like receptors (RLR) signaling cascade, over-production of type-I IFNs and pro-inflammatory cytokines. ADAR1 knockdown enhanced expression of HPV proteins, a process dependent on innate immune function as no A-to-I editing could be identified in HPV transcripts. A genetic association study was performed in a cohort of HPV/HIV infected individuals followed for a median of 6 years (range 0.1–24). We identified the low frequency haplotype AACCAT significantly associated with recurrent HPV dysplasia, suggesting a role of ADAR1 in the outcome of HPV infection in HIV+ individuals. In summary, our results suggest that ADAR1-mediated innate immune activation may influence HPV disease outcome, therefore indicating that modification of innate immune effectors regulated by ADAR1 could be a therapeutic strategy against HPV infection.

Outer membrane vesicles of Neisseria lactamica as a potential mucosal adjuvant

Vaccine ◽  
2006 ◽  
Vol 24 (2) ◽  
pp. 206-214 ◽  
Author(s):  
Gretel Sardiñas ◽  
Karen Reddin ◽  
Rolando Pajon ◽  
Andrew Gorringe
Keyword(s):  
Outer Membrane ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Mucosal Adjuvant ◽  
Neisseria Lactamica

scholarly journals TH17 cells expressing CD146 are significantly increased in patients with Systemic sclerosis

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Amira Gabsi ◽  
Xavier Heim ◽  
Akram Dlala ◽  
Asma Gati ◽  
Haifa Sakhri ◽  
...  
Keyword(s):  
Systemic Sclerosis ◽  
Th17 Cells ◽  
Vascular System ◽  
Adaptive Immune Response ◽  
Autoimmune Disorder ◽  
Soluble Form ◽  
Adaptive Immune ◽  
Th17 Lymphocytes

AbstractSystemic sclerosis (SSc) is an autoimmune disorder characterized by vascular damage, excessive fibrosis and abnormal T cells immune-regulation. CD146 is an adhesion molecule essentially expressed in the vascular system, but also on TH17 lymphocytes. In view of the recently described role of CD146 in SSc, we hypothesized an involvement of CD146 positive TH17 cells in this disease. Compared to healthy controls, we showed that both soluble form of CD146 (sCD146), and IL17A levels were increased in patients with SSc with a positive correlation between both factors. A significant increase in TH17 cells attested by an increase of RORγT, IL17A mRNA and CD4+ IL17A+ cell was observed in patients with SSc. Interestingly, the percentage of TH17 cells expressing CD146 was higher in patients with SSc and inversely correlated with pulmonary fibrosis. In vitro experiments showed an augmentation of the percentage of TH17 cells expressing CD146 after cell treatment with sCD146, suggesting that, in patients the increase of this sub-population could be the consequence of the sCD146 increase in serum. In conclusion, TH17 cells expressing CD146 could represent a new component of the adaptive immune response, opening the way for the generation of new tools for the management of SSc.

scholarly journals Long Non-coding RNAs RN7SK and GAS5 Regulate Macrophage Polarization and Innate Immune Responses

2020 ◽  
Vol 11 ◽  
Author(s):  
Imran Ahmad ◽  
Araceli Valverde ◽  
Raza Ali Naqvi ◽  
Afsar R. Naqvi
Keyword(s):  
Immune Responses ◽  
Epigenetic Regulation ◽  
Innate Immune ◽  
Differentially Expressed ◽  
Immune Functions ◽  
Innate Immune Responses ◽  
Antigen Uptake ◽  
Non Coding Rnas

Macrophages (Mφ) are immune cells that exhibit remarkable functional plasticity. Identification of novel endogenous factors that can regulate plasticity and innate immune functions of Mφ will unravel new strategies to curb immune-related diseases. Long non-coding RNAs (lncRNAs) are a class of endogenous, non-protein coding, regulatory RNAs that are increasingly being associated with various cellular functions and diseases. Despite their ubiquity and abundance, lncRNA-mediated epigenetic regulation of Mφ polarization and innate immune functions is poorly studied. This study elucidates the regulatory role of lncRNAs in monocyte to Mφ differentiation, M1/M2 dichotomy and innate immune responses. Expression profiling of eighty-eight lncRNAs in monocytes and in vitro differentiated M2 Mφ identified seventeen differentially expressed lncRNAs. Based on fold-change and significance, we selected four differentially expressed lncRNAs viz., RN7SK, GAS5, IPW, and ZFAS1 to evaluate their functional impact. LncRNA knockdown was performed on day 3 M2 Mφ and the impact on polarization was assessed on day 7 by surface marker analysis. Knockdown of RN7SK and GAS5 showed downregulation of M2 surface markers (CD163, CD206, or Dectin) and concomitant increase in M1 markers (MHC II or CD23). RN7SK or GAS5 knockdown showed no significant impact on CD163, CD206, or CD23 transcripts. M1/M2 markers were not impacted by IPW or ZFAS1 knockdown. Functional regulation of antigen uptake/processing and phagocytosis, two central innate immune pathways, by candidate lncRNA was assessed in M1/M2 Mφ. Compared to scramble, enhanced antigen uptake and processing were observed in both M1/M2 Mφ transfected with siRNA targeting GAS5 and RN7SK but not IPW and ZFAS1. In addition, knockdown of RN7SK significantly augmented uptake of labelled E. coli in vitro by M1/M2 Mφ, while no significant difference was in GAS5 silencing cells. Together, our results highlight the instrumental role of lncRNA (RN7SK and GAS5)-mediated epigenetic regulation of macrophage differentiation, polarization, and innate immune functions.

scholarly journals The Mutation of Conservative Asp268 Residue in the Peptidoglycan-Associated Domain of the OmpA Protein Affects Multiple Acinetobacter baumannii Virulence Characteristics

Molecules ◽  
2019 ◽  
Vol 24 (10) ◽  
pp. 1972 ◽  
Author(s):  
Jūratė Skerniškytė ◽  
Emilija Karazijaitė ◽  
Julien Deschamps ◽  
Renatas Krasauskas ◽  
Romain Briandet ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Outer Membrane ◽  
Protein A ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Clinical Strain ◽  
Infection Model ◽  
Terminal Domain ◽  
Ompa Protein

Acinetobacter baumannii is a nosocomial human pathogen of increasing concern due to its multidrug resistance profile. The outer membrane protein A (OmpA) is an abundant bacterial cell surface component involved in A. baumannii pathogenesis. It has been shown that the C-terminal domain of OmpA is located in the periplasm and non-covalently associates with the peptidoglycan layer via two conserved amino acids, thereby anchoring OmpA to the cell wall. Here, we investigated the role of one of the respective residues, D268 in OmpA of A. baumannii clinical strain Ab169, on its virulence characteristics by complementing the ΔompA mutant with the plasmid-borne ompAD268A allele. We show that while restoring the impaired biofilm formation of the ΔompA strain, the Ab169ompAD268A mutant tended to form bacterial filaments, indicating the abnormalities in cell division. Moreover, the Ab169 OmpA D268-mediated association to peptidoglycan was required for the manifestation of twitching motility, desiccation resistance, serum-induced killing, adhesion to epithelial cells and virulence in a nematode infection model, although it was dispensable for the uptake of β-lactam antibiotics by outer membrane vesicles. Overall, the results of this study demonstrate that the OmpA C-terminal domain-mediated association to peptidoglycan is critical for a number of virulent properties displayed by A. baumannii outside and within the host.

scholarly journals RNA-Sequencing Analyses of Small Bacterial RNAs and their Emergence as Virulence Factors in Host-Pathogen Interactions

2020 ◽  
Vol 21 (5) ◽  
pp. 1627 ◽  
Author(s):  
Idrissa Diallo ◽  
Patrick Provost
Keyword(s):  
Rna Sequencing ◽  
Virulence Factors ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Rna Seq ◽  
Host Pathogen Interactions ◽  
Bioinformatics Analyses ◽  
Additional Layer ◽  
Host Pathogen

Proteins have long been considered to be the most prominent factors regulating so-called invasive genes involved in host-pathogen interactions. The possible role of small non-coding RNAs (sRNAs), either intracellular, secreted or packaged in outer membrane vesicles (OMVs), remained unclear until recently. The advent of high-throughput RNA-sequencing (RNA-seq) techniques has accelerated sRNA discovery. RNA-seq radically changed the paradigm on bacterial virulence and pathogenicity to the point that sRNAs are emerging as an important, distinct class of virulence factors in both gram-positive and gram-negative bacteria. The potential of OMVs, as protectors and carriers of these functional, gene regulatory sRNAs between cells, has also provided an additional layer of complexity to the dynamic host-pathogen relationship. Using a non-exhaustive approach and through examples, this review aims to discuss the involvement of sRNAs, either free or loaded in OMVs, in the mechanisms of virulence and pathogenicity during bacterial infection. We provide a brief overview of sRNA origin and importance and describe the classical and more recent methods of identification that have enabled their discovery, with an emphasis on the theoretical lower limit of RNA sizes considered for RNA sequencing and bioinformatics analyses.

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