Browse
Submit Data
Databases
API
Help

Dataset Information

29 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Novel human recombinant antibodies against Mycobacterium tuberculosis antigen 85B.

ABSTRACT: BACKGROUND: Tuberculosis is the leading cause of death due to bacterial infections worldwide, mainly caused by Mycobacterium tuberculosis. The antigen 85 complex comprises a set of major secreted proteins of M. tuberculosis, which are potential biomarkers for diagnostic. RESULTS: In this work, the first human single chain fragment variable (scFv) antibodies specific for the tuberculosis biomarker 85 B were selected by phage display from naïve antibody gene libraries (HAL7/8). Produced as scFv-Fc in mammalian cells, these antibodies were further characterized and analysed for specificity and applicability in different tuberculosis antigen detection assays. Sandwich detection of recombinant 85 B was successful in enzyme linked immunosorbent assay (ELISA), lateral flow immunoassay and immunoblot. Whereas detection of M. tuberculosis cell extracts and culture filtrates was only possible in direct ELISA and immunoblot assays. It was found that the conformation of 85 B, depending on sample treatment, influenced antigen detection. CONCLUSIONS: Recombinant antibodies, selected by phage display, may be applicable for 85 B detection in various assays. These antibodies are candidates for the development of future point of care tuberculosis diagnostic kits. Using 85 B as a biomarker, the antigen conformation influenced by sample treatment is important.

SUBMITTER: Fuchs M

PROVIDER: S-EPMC4119940 | biostudies-literature | 2014

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

A recombinant bovine adenoviral mucosal vaccine expressing mycobacterial antigen-85B generates robust protection against tuberculosis in mice.

Project description:Although the BCG vaccine offers partial protection, tuberculosis remains a leading cause of infectious disease death, killing ∼1.5 million people annually. We developed mucosal vaccines expressing the autophagy-inducing peptide C5 and mycobacterial Ag85B-p25 epitope using replication-defective human adenovirus (HAdv85C5) and bovine adenovirus (BAdv85C5) vectors. BAdv85C5-infected dendritic cells (DCs) expressed a robust transcriptome of genes regulating antigen processing compared to HAdv85C5-infected DCs. BAdv85C5-infected DCs showed enhanced galectin-3/8 and autophagy-dependent in vitro Ag85B-p25 epitope presentation to CD4 T cells. BCG-vaccinated mice were intranasally boosted using HAdv85C5 or BAdv85C5 followed by infection using aerosolized Mycobacterium tuberculosis (Mtb). BAdv85C5 protected mice against tuberculosis both as a booster after BCG vaccine (>1.4-log10 reduction in Mtb lung burden) and as a single intranasal dose (>0.5-log10 reduction). Protection was associated with robust CD4 and CD8 effector (TEM), central memory (TCM), and CD103+/CD69+ lung-resident memory (TRM) T cell expansion, revealing BAdv85C5 as a promising mucosal vaccine for tuberculosis.

| S-EPMC8385328 | biostudies-literature

Cell wall skeleton of Mycobacterium bovis BCG enhances the vaccine potential of antigen 85B against tuberculosis by inducing Th1 and Th17 responses.

Project description:A safe and effective adjuvant is necessary to induce reliable protective efficacy of the protein-based vaccines against tuberculosis (TB). Mycobacterial components, such as synthetic cord factor and arabinogalactan, have been used as one of the adjuvant components. Mycobacterium bovis bacillus Calmette- Guérin cell-wall skeleton (BCG-CWS) has been used as an effective immune-stimulator. However, it is not proven whether BCG-CWS can be an effective adjuvant for the subunit protein vaccine of TB. In this study, we demonstrated that the BCG-CWS effectively coupled with Ag85B and enhanced the conjugated Ag85B activity on the maturation of dendritic cells (DCs). Ag85B-BCG-CWS-matured DCs induced significant Th1 and Th17 responses when compared to BCG-CWS or Ag85B alone. In addition, significant Ag85B-specific Th1 and Th17 responses were induced in Ag85B-BCG-CWS-immunized mice before infection with M. tuberculosis and maintained after infection. Moreover, Ag85B-BCG-CWS showed significant protective effect comparable to live BCG at 6 weeks after infection and maintained its protective efficacy at 32 weeks post-challenge, whereas live BCG did not. These results suggest that the BCG-CWS may be an effective adjuvant candidate for a protein-based vaccine against TB.

| S-EPMC6407753 | biostudies-literature

Human antibodies targeting a Mycobacterium transporter protein mediate protection against tuberculosis.

Project description:Mycobacterium tuberculosis (Mtb) exposure drives antibody responses, but whether patients with active tuberculosis elicit protective antibodies, and against which antigens, is still unclear. Here we generate monoclonal antibodies from memory B cells of one patient to investigate the B cell responses during active infection. The antibodies, members of four distinct B cell clones, are directed against the Mtb phosphate transporter subunit PstS1. Antibodies p4-36 and p4-163 reduce Mycobacterium bovis-BCG and Mtb levels in an ex vivo human whole blood growth inhibition assay in an FcR-dependent manner; meanwhile, germline versions of p4-36 and p4-163 do not bind Mtb. Crystal structures of p4-36 and p4-170, complexed to PstS1, are determined at 2.1 Å and 2.4 Å resolution, respectively, to reveal two distinctive PstS1 epitopes. Lastly, a prophylactic p4-36 and p4-163 treatment in Mtb-infected Balb/c mice reduces bacterial lung burden by 50%. Our study shows that inhibitory anti-PstS1 B cell responses arise during active tuberculosis.

| S-EPMC7840946 | biostudies-literature

A recombinant Mycobacterium smegmatis induces potent bactericidal immunity against Mycobacterium tuberculosis.

Project description:We report the involvement of an evolutionarily conserved set of mycobacterial genes, the esx-3 region, in evasion of bacterial killing by innate immunity. Whereas high-dose intravenous infections of mice with the rapidly growing mycobacterial species Mycobacterium smegmatis bearing an intact esx-3 locus were rapidly lethal, infection with an M. smegmatis ?esx-3 mutant (here designated as the IKE strain) was controlled and cleared by a MyD88-dependent bactericidal immune response. Introduction of the orthologous Mycobacterium tuberculosis esx-3 genes into the IKE strain resulted in a strain, designated IKEPLUS, that remained susceptible to innate immune killing and was highly attenuated in mice but had a marked ability to stimulate bactericidal immunity against challenge with virulent M. tuberculosis. Analysis of these adaptive immune responses indicated that the highly protective bactericidal immunity elicited by IKEPLUS was dependent on CD4(+) memory T cells and involved a distinct shift in the pattern of cytokine responses by CD4(+) cells. Our results establish a role for the esx-3 locus in promoting mycobacterial virulence and also identify the IKE strain as a potentially powerful candidate vaccine vector for eliciting protective immunity to M. tuberculosis.

| S-EPMC3250071 | biostudies-literature

Enoyl-coenzyme A hydratase and antigen 85B of Mycobacterium habana are specifically recognized by antibodies in sera from leprosy patients.

Project description:Leprosy is an infectious disease caused by Mycobacterium leprae, which is a noncultivable bacterium. One of the principal goals of leprosy research is to develop serological tests that will allow identification and early treatment of leprosy patients. M. habana is a cultivable nonpathogenic mycobacterium and candidate vaccine for leprosy, and several antigens that cross-react between M. leprae and M. habana have been discovered. The aim of the present study was to extend the identification of cross-reactive antigens by identifying M. habana proteins that reacted by immunoblotting with antibodies in serum samples from leprosy patients but not with antibodies in sera from tuberculosis (TB) patients or healthy donors (HDs). A 28-kDa antigen that specifically reacted with sera from leprosy patients was identified. To further characterize this antigen, protein spots were aligned in two-dimensional polyacrylamide gels and Western blots. Spots cut out from the gels were then analyzed by mass spectrometry. Two proteins were identified: enoyl-coenzyme A hydratase (lipid metabolism; ML2498) and antigen 85B (Ag85B; mycolyltransferase; ML2028). These proteins represent promising candidates for the design of a reliable tool for the serodiagnosis of lepromatous leprosy, which is the most frequent form in Mexico.

| S-EPMC3147323 | biostudies-literature

Mycobacterium tuberculosis origin of replication and the promoter for immunodominant secreted antigen 85B are the targets of MtrA, the essential response regulator.

Project description:Efficient proliferation of Mycobacterium tuberculosis (Mtb) inside macrophage requires that the essential response regulator MtrA be optimally phosphorylated. However, the genomic targets of MtrA have not been identified. We show by chromatin immunoprecipitation and DNase I footprinting that the chromosomal origin of replication, oriC, and the promoter for the major secreted immunodominant antigen Ag85B, encoded by fbpB, are MtrA targets. DNase I footprinting analysis revealed that MtrA recognizes two direct repeats of GTCACAgcg-like sequences and that MtrA approximately P, the phosphorylated form of MtrA, binds preferentially to these targets. The oriC contains several MtrA motifs, and replacement of all motifs or of a single select motif with TATATA compromises the ability of oriC plasmids to maintain stable autonomous replication in wild type and MtrA-overproducing strains, indicating that the integrity of the MtrA motif is necessary for oriC replication. The expression of the fbpB gene is found to be down-regulated in Mtb cells upon infection when these cells overproduce wild type MtrA but not when they overproduce a nonphosphorylated MtrA, indicating that MtrA approximately P regulates fbpB expression. We propose that MtrA is a regulator of oriC replication and that the ability of MtrA to affect apparently unrelated targets, i.e. oriC and fbpB, reflects its main role as a coordinator between the proliferative and pathogenic functions of Mtb.

| S-EPMC2871449 | biostudies-literature

Recombinant BCG Expressing LTAK63 Adjuvant induces Superior Protection against Mycobacterium tuberculosis.

Project description:In order to develop an improved BCG vaccine against tuberculosis we have taken advantage of the adjuvant properties of a non-toxic derivative of Escherichia coli heat labile enterotoxin (LT), LTAK63. We have constructed rBCG strains expressing LTAK63 at different expression levels. Mice immunized with BCG expressing low levels of LTAK63 (rBCG-LTAK63lo) showed higher Th1 cytokines and IL-17 in the lungs, and when challenged intratracheally with Mycobacterium tuberculosis displayed a 2.0-3.0?log reduction in CFU as compared to wild type BCG. Histopathological analysis of lung tissues from protected mice revealed a reduced inflammatory response. Immunization with rBCG-LTAK63lo also protected against a 100-fold higher challenge dose. Mice immunized with rBCG-LTAK63lo produced an increase in TGF-? as compared with BCG after challenge, with a corresponding reduction in Th1 and Th17 cytokines, as determined by Real Time RT-PCR. Furthermore, rBCG-LTAK63lo also displays protection against challenge with a highly virulent Beijing isolate. Our findings suggest that BCG with low-level expression of the LTAK63 adjuvant induces a stronger immune response in the lungs conferring higher levels of protection, and a novel mechanism subsequently triggers a regulatory immune response, which then limits the pathology. The rBCG-LTAK63lo strain can be the basis of an improved vaccine against tuberculosis.

| S-EPMC5437048 | biostudies-literature

Novel Pyrazole-Containing Compounds Active against Mycobacterium tuberculosis.

Project description:In this study, a series of 49 five-membered heterocyclic compounds containing either a pyridine- or a pyrrole-type nitrogen were synthesized and tested against Mycobacterium tuberculosis. Among them, only the 1,3,5-trisubstituted pyrazoles 5-49 exhibited minimum inhibitory concentration values in the low micromolar range, and some also exhibited an improved physicochemical profile without cytotoxic effects. Three pyrazoles were subjected to an animal tuberculosis efficacy model, and compound 6 induced a statistically significant difference in lung bacterial counts compared with untreated mice. Moreover, to determine the target of this series, resistors were generated, and whole genome sequencing revealed mutations in the mmpL3 gene.

| S-EPMC6792160 | biostudies-literature

A novel tuberculosis antigen identified from human tuberculosis granulomas.

Project description:Tuberculosis is a global infectious disease caused by Mycobacterium tuberculosis (Mtb). Although novel Mtb biomarkers from both the pathogen and host have been studied, more breakthroughs are still needed to meet different clinic requirements. In an effort to identify Mtb antigens, chaperone-peptide complexes were purified from TB infected lungs using free-solution isoelectric focusing combined with high resolution LTQ Orbitrap Velos mass spectrometry. Antigen specific cellular immune responses in vitro were then examined. Those efforts led to the identification of six Mtb peptides only identified in Tuberculosis lung samples and that were not found in the control samples. Additionally, antigen-specific IFN-γ secretion, T-cell proliferation, cytokine expression, and a cytotoxic assay were also evaluated. Among the peptides isolated, we identified a 34 amino acid peptide named PKAp belonging to a serine/threonine-protein kinase, as being able to generate Mtb-specific cellular immune responses as noted by elevated antigen-specific cytokine secretion levels, increased CD8(+) T-cell proliferation and a strong cytotoxic lymphocyte (CTL) response. Moreover, the immune stimulating abilities of PKAp were further validated in vivo, with target peptide immunized mice showing an increased cellular IFN-γ in both the lungs and spleen without causing immunopathogenesis. In conclusion, we identified novel functional Mtb antigens directly from the granulomatous lesions of Tuberculosis patients, inducing not only significant antigen-specific IFN-γ secretion but also a marked cytotoxic lymphocyte functional response. These findings indicated that PKAp has potential as a novel antigen biomarker for vaccine development.

| S-EPMC4390254 | biostudies-literature

Deciphering Mycobacterium tuberculosis glycan epitopes through clustering of human polyclonal and isolating novel monoclonal antibodies I

Project description:The immunomodulatory mycobacterial surface antigen lipoarabinomannan (LAM) with its immunogenic glycan component arabinomannan (AM) facilitates Mycobacterium tuberculosis’ (Mtb) escape from the host’s immune response. Some but not all antibodies against AM can protect against TB. To better understand which of AM’s structures to target, we must first identify the spectrum of its epitopes. We here used synthetic AM oligosaccharide motifs to deplete sera from subjects along the spectrum of Mtb infection. Performing cluster analysis, we were able to predict AM’s immunogenic structures and delineate how antibody reactivity to them is influenced by Mtb infection states.

2024-06-01 | GSE263496 | GEO

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data