Combined meningococcal serogroup A and W135 outer-membrane vesicles activate cell-mediated immunity and long-term memory responses against non-covalent capsular polysaccharide A

Outer membrane vesicles (OMVs) contain biologically active proteins, lipoolysaccharide (LPS), periplasmic and membrane-bound proteins and are known to perform diverse biological functions. OMVs from Brucella abortus S19 were isolated and characterized by transmission electron microscopy (TEM), SDS-PAGE and immunoreactivity was investigated by western blotting. On TEM, bilayered spherical structures of 50-200 nm were observed. SDS-PAGE of OMVs revealed approximate bands size of 82 kDa, 68 kDa, 38 kDa, 32 kDa, 29 kDa and 18 kDa. Western blot analysis of OMVs revealed a dominant immunoreactive band of 38 kDa that correspond to some major outer membrane proteins. Humoral immune response was measured by indirect ELISA which showed that OMV specific antibodies were detected from 7th day post immunization (DPI) onwards and showed a rising trend up to 35th DPI. Cell mediated immune (CMI) response against OMVs as evidenced by the proliferation of splenocytes have also been observed. Thus OMVs were found to possess immunogenic proteins which had potential to induce both humoral as well as cell mediated immunity. After correlating this immune response with protection it has been concluded that OMV can be used as one of the vaccine candidate against brucellosis.

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The Opportunistic Pathogen Vibrio vulnificus Produces Outer Membrane Vesicles in a Spatially Distinct Manner Related to Capsular Polysaccharide

Frontiers in Microbiology ◽

10.3389/fmicb.2017.02177 ◽

2017 ◽

Vol 8 ◽

Cited By ~ 12

Author(s):

Cheri M. Hampton ◽

Ricardo C. Guerrero-Ferreira ◽

Rachel E. Storms ◽

Jeannette V. Taylor ◽

Hong Yi ◽

...

Keyword(s):

Outer Membrane ◽

Capsular Polysaccharide ◽

Vibrio Vulnificus ◽

Membrane Vesicles ◽

Opportunistic Pathogen ◽

Outer Membrane Vesicles

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Characterization of Outer Membrane Vesicles fromBrucella melitensisand Protection Induced in Mice

Clinical and Developmental Immunology ◽

10.1155/2012/352493 ◽

2012 ◽

Vol 2012 ◽

pp. 1-13 ◽

Cited By ~ 34

Author(s):

Eric Daniel Avila-Calderón ◽

Ahidé Lopez-Merino ◽

Neeta Jain ◽

Humberto Peralta ◽

Edgar Oliver López-Villegas ◽

...

Keyword(s):

Outer Membrane ◽

Virulent Strain ◽

Membrane Vesicles ◽

Outer Membrane Vesicles ◽

Saline Control ◽

Control Group ◽

Cell Mediated Immunity ◽

Rough Strain ◽

Smooth Strain

The outer membrane vesicles (OMVs) from smoothB. melitensis16 M and a derived rough mutant, VTRM1 strain, were purified and characterized with respect to protein content and induction of immune responses in mice. Proteomic analysis showed 29 proteins present in OMVs fromB. melitensis16 M; some of them are well-knownBrucellaimmunogens such as SOD, GroES, Omp31, Omp25, Omp19, bp26, and Omp16. OMVs from a rough VTRM1 induced significantly higher expression of IL-12, TNFα, and IFNγ genes in bone marrow dendritic cells than OMVs from smooth strain 16 M. Relative to saline control group, mice immunized intramuscularly with rough and smooth OMVs were protected from challenge with virulent strainB. melitensis16 M just as well as the group immunized with live strainB. melitensisRev1 (P<0.005). Additionally, the levels of serum IgG2a increased in mice vaccinated with OMVs from rough strain VTRM1 consistent with the induction of cell-mediated immunity.

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Neisseria meningitidis Native Outer Membrane Vesicles Containing Different Lipopolysaccharide Glycoforms as Adjuvants for Meningococcal and Nonmeningococcal Antigens

Clinical and Vaccine Immunology ◽

10.1128/cvi.00561-13 ◽

2013 ◽

Vol 21 (2) ◽

pp. 234-242 ◽

Cited By ~ 12

Author(s):

Jerry C. Nagaputra ◽

Christine S. Rollier ◽

Manish Sadarangani ◽

J. Claire Hoe ◽

Ojas Hrakesh Mehta ◽

...

Keyword(s):

Outer Membrane ◽

Tetanus Toxoid ◽

Capsular Polysaccharide ◽

Membrane Vesicles ◽

Outer Membrane Vesicles ◽

Aluminum Salt ◽

Adjuvant Effect ◽

Monophosphoryl Lipid A ◽

Bactericidal Antibody ◽

Antibody Titers

ABSTRACTWe evaluated the adjuvant effect of a modified glycoform of lipopolysaccharide (LPS) (LgtB-LpxL1) compared to that of the nonmodified glycoform Lpxl1 serogroup B meningococcal H44/76 native outer membrane vesicles (nOMVs) on immune responses to vaccination with the recombinant meningococcal protein, rPorA, tetanus toxoid, or meningococcal serogroup C capsular polysaccharide. We used LgtB-LpxL1 LPS because the disruption of thelgtBgene, which results in the exposure ofN-acetylglucosamine-galactose-glucose residues in the LPS outer core, has been shown to enhance the activation of human dendritic cellsin vitro. The responses were compared to those of a monophosphoryl lipid A (MPL)-based adjuvant and to an aluminum hydroxide suspension. The nOMVs induced blood serum IgG responses against each of the three antigens comparable to those obtained with MPL or aluminum salt. However, nOMVs elicited (i) a lower IgG1/IgG2a ratio against rPorA and (ii) serum bactericidal antibody titers superior to those achieved with aluminum salt, reaching similar titers to those obtained with MPL. Similarly, bactericidal antibody titers induced by immunization with meningococcal serogroup C polysaccharide and nOMVs were similar to those obtained using MPL but were better than those with aluminum salt. Immunization with tetanus toxoid and nOMVs resulted in tetanus toxoid-specific IgG responses similar to those obtained when adjuvanted with aluminum salt. These results highlight the potential utility of meningococcal LpxL1 LPS-containing nOMVs as an adjuvant for recombinant meningococcal protein vaccines and suggest their possible use with a variety of other antigens.

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Recombinant Group A Carbohydrate backbone embedded into Outer Membrane Vesicles is a potent vaccine candidate targeting Group A Streptococcus from Streptococcus pyogenes and Streptococcus dysgalactiae subsp. equisimilis

10.1101/2021.11.12.468441 ◽

2021 ◽

Author(s):

Sowmya Ajay Castro ◽

Sarah Thomson ◽

Azul Zorzoli ◽

Benjamin H Meyer ◽

Mark Reglinski ◽

...

Keyword(s):

Outer Membrane ◽

Vaccine Candidate ◽

Group A Streptococcus ◽

Membrane Vesicles ◽

Outer Membrane Vesicles ◽

Long Term Memory ◽

E Coli ◽

Wide Range ◽

Group A ◽

First Time

Group A Streptococcus (GAS) are responsible for a wide range of human-exclusive infections, annually killing more than 500,000 people. Antibiotic resistance incidence of invasive GAS increased in the past decade and emphasises the need to develop a universal GAS vaccine. We have produced, for the first time, a recombinant polyrhamnose backbone (pRha), a validated universal GAS vaccine candidate. E. coli outer membrane vesicles (OMVs) carrying pRha were investigated for their immunogenicity and efficacy in an animal model. Our results suggest that pRha-OMVs induce specific antibodies which recognise Group A Carbohydrate (GAC) from S pyogenes and S. dysgalactiae subsp. equisimilis. Increased IgG levels correlate with increased bactericidal killing of the hypervirulent GAS M89 strain. Elevated IL-17a from pRha-OMV-immunised splenocytes indicates possible stimulation of long-term memory immune cells. We are the first to report efficacy and potency of this unique, exogenously produced polysaccharide, pRha, in the induction of humoral-mediated immune responses to GAS.

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Conceptual short-term memory (CSTM) supports core claims of Christiansen and Chater

Behavioral and Brain Sciences ◽

10.1017/s0140525x15000928 ◽

2016 ◽

Vol 39 ◽

Author(s):

Mary C. Potter

Keyword(s):

Working Memory ◽

Rapid Serial Visual Presentation ◽

Language Comprehension ◽

Short Term Memory ◽

Visual Presentation ◽

Long Term Memory ◽

Short Term ◽

Term Memory ◽

Use Of Knowledge

AbstractRapid serial visual presentation (RSVP) of words or pictured scenes provides evidence for a large-capacity conceptual short-term memory (CSTM) that momentarily provides rich associated material from long-term memory, permitting rapid chunking (Potter 1993; 2009; 2012). In perception of scenes as well as language comprehension, we make use of knowledge that briefly exceeds the supposed limits of working memory.

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Comparison of Auditory, Language, Memory, and Attention Abilities in Children With and Without Listening Difficulties

American Journal of Audiology ◽

10.1044/2020_aja-20-00018 ◽

2020 ◽

Vol 29 (4) ◽

pp. 710-727

Author(s):

Beula M. Magimairaj ◽

Naveen K. Nagaraj ◽

Alexander V. Sergeev ◽

Natalie J. Benafield

Keyword(s):

Auditory Processing ◽

Short Term Memory ◽

Group Differences ◽

Long Term Memory ◽

Short Term ◽

Significant Group ◽

Term Memory ◽

Memory And Attention ◽

Speed And Accuracy

Objectives School-age children with and without parent-reported listening difficulties (LiD) were compared on auditory processing, language, memory, and attention abilities. The objective was to extend what is known so far in the literature about children with LiD by using multiple measures and selective novel measures across the above areas. Design Twenty-six children who were reported by their parents as having LiD and 26 age-matched typically developing children completed clinical tests of auditory processing and multiple measures of language, attention, and memory. All children had normal-range pure-tone hearing thresholds bilaterally. Group differences were examined. Results In addition to significantly poorer speech-perception-in-noise scores, children with LiD had reduced speed and accuracy of word retrieval from long-term memory, poorer short-term memory, sentence recall, and inferencing ability. Statistically significant group differences were of moderate effect size; however, standard test scores of children with LiD were not clinically poor. No statistically significant group differences were observed in attention, working memory capacity, vocabulary, and nonverbal IQ. Conclusions Mild signal-to-noise ratio loss, as reflected by the group mean of children with LiD, supported the children's functional listening problems. In addition, children's relative weakness in select areas of language performance, short-term memory, and long-term memory lexical retrieval speed and accuracy added to previous research on evidence-based areas that need to be evaluated in children with LiD who almost always have heterogenous profiles. Importantly, the functional difficulties faced by children with LiD in relation to their test results indicated, to some extent, that commonly used assessments may not be adequately capturing the children's listening challenges. Supplemental Material https://doi.org/10.23641/asha.12808607

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Retrieval from Memory or Procedural Strategies for Addition Problems

Swiss Journal of Psychology ◽

10.1024/1421-0185/a000036 ◽

2011 ◽

Vol 70 (1) ◽

pp. 35-39 ◽

Cited By ~ 3

Author(s):

Muriel Fanget ◽

Catherine Thevenot ◽

Caroline Castel ◽

Michel Fayol

Keyword(s):

Reaction Times ◽

Long Term Memory ◽

Verbal Reports ◽

Term Memory ◽

Simple Addition ◽

Memory Traces ◽

Addition Problem ◽

Retrieval From Memory ◽

Calculation Procedures

In this study, we used a paradigm recently developed ( Thevenot, Fanget, & Fayol, 2007 ) to determine whether 10-year-old children solve simple addition problems by retrieval of the answer from long-term memory or by calculation procedures. Our paradigm is unique in that it does not rely on reaction times or verbal reports, which are known to potentially bias the results, especially in children. Rather, it takes advantage of the fact that calculation procedures degrade the memory traces of the operands, so that it is more difficult to recognize them when they have been involved in the solution of an addition problem by calculation rather than by retrieval. The present study sharpens the current conclusions in the literature and shows that, when the sum of addition problems is up to 10, children mainly use retrieval, but when it is greater than 10, they mainly use calculation procedures.

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The Acute Effect of Alcohol on Various Memory Processes

Journal of Psychophysiology ◽

10.1027/0269-8803/a000038 ◽

2010 ◽

Vol 24 (4) ◽

pp. 249-252 ◽

Cited By ~ 7

Author(s):

Márk Molnár ◽

Roland Boha ◽

Balázs Czigler ◽

Zsófia Anna Gaál

Keyword(s):

Low Dose ◽

Short Term Memory ◽

Acute Effect ◽

Long Term Memory ◽

Term Memory ◽

Memory Processes ◽

Different Types ◽

The Brain ◽

Legal Consequences

This review surveys relevant and recent data of the pertinent literature regarding the acute effect of alcohol on various kinds of memory processes with special emphasis on working memory. The characteristics of different types of long-term memory (LTM) and short-term memory (STM) processes are summarized with an attempt to relate these to various structures in the brain. LTM is typically impaired by chronic alcohol intake but according to some data a single dose of ethanol may have long lasting effects if administered at a critically important age. The most commonly seen deleterious acute effect of alcohol to STM appears following large doses of ethanol in conditions of “binge drinking” causing the “blackout” phenomenon. However, with the application of various techniques and well-structured behavioral paradigms it is possible to detect, albeit occasionally, subtle changes of cognitive processes even as a result of a low dose of alcohol. These data may be important for the consideration of legal consequences of low-dose ethanol intake in conditions such as driving, etc.

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