Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

B cell development in GALT: role of bacterial superantigen-like molecules.

ABSTRACT: Intestinal bacteria drive the formation of lymphoid tissues, and in rabbit, bacteria also promote development of the preimmune Ab repertoire and positive selection of B cells in GALT. Previous studies indicated that Bacillus subtilis promotes B cell follicle formation in GALT, and we investigated the mechanism by which B. subtilis stimulates B cells. We found that spores of B. subtilis and other Bacillus species, including Bacillus anthracis, bound rabbit IgM through an unconventional, superantigen-like binding site, and in vivo, surface molecules of B. anthracis spores promoted GALT development. Our study provides direct evidence that B cell development in GALT may be driven by superantigen-like molecules, and furthermore, that bacterial spores modulate host immunity.

SUBMITTER: Severson KM

PROVIDER: S-EPMC3419943 | biostudies-literature | 2010 Jun

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

B cell development in GALT: role of bacterial superantigen-like molecules.

Severson Kari M KM Mallozzi Michael M Driks Adam A Knight Katherine L KL

Journal of immunology (Baltimore, Md. : 1950) 20100507 12

Intestinal bacteria drive the formation of lymphoid tissues, and in rabbit, bacteria also promote development of the preimmune Ab repertoire and positive selection of B cells in GALT. Previous studies indicated that Bacillus subtilis promotes B cell follicle formation in GALT, and we investigated the mechanism by which B. subtilis stimulates B cells. We found that spores of B. subtilis and other Bacillus species, including Bacillus anthracis, bound rabbit IgM through an unconventional, superanti ...[more]

PMID: 20483765

Similar Datasets

Bacterial lectin BambL acts as a B cell superantigen.

Project description:B cell superantigens crosslink conserved domains of B cell receptors (BCRs) and cause dysregulated, polyclonal B cell activation irrespective of normal BCR-antigen complementarity. The cells typically succumb to activation-induced cell death, which can impede the adaptive immune response and favor infection. In the present study, we demonstrate that the fucose-binding lectin of Burkholderia ambifaria, BambL, bears functional resemblance to B cell superantigens. By engaging surface glycans, the bacterial lectin activated human peripheral blood B cells, which manifested in the surface expression of CD69, CD54 and CD86 but became increasingly cytotoxic at higher concentrations. The effects were sensitive to BCR pathway inhibitors and excess fucose, which corroborates a glycan-driven mode of action. Interactome analyses in a model cell line suggest BambL binds directly to glycans of the BCR and regulatory coreceptors. In vitro, BambL triggered BCR signaling and induced CD19 internalization and degradation. Owing to the lectin's six binding sites, we propose a BCR activation model in which BambL functions as a clustering hub for receptor glycans, modulates normal BCR regulation, and induces cell death through exhaustive activation.

| S-EPMC8629787 | biostudies-literature

Requirement for BAFF and APRIL during B cell development in GALT.

Project description:The effects of B cell-activating factor belonging to the TNF family (BAFF) on B cell maturation and survival in the mouse are relatively well understood. In contrast, little is known about the role of BAFF in B cell development in other mammals, such as rabbits, that use GALT to develop and maintain the B cell compartment. We examined the expression and requirement of BAFF and a proliferation-inducing ligand (APRIL) during peripheral B cell development in young rabbits. By neutralizing BAFF and APRIL in neonates with a soluble decoy receptor, transmembrane activator calcium modulator and cyclophilin ligand interactor-Fc, we found a marked reduction in the number of peripheral B cells, but found no change in the bone marrow (BM) compartment. In the appendix, the size and number of proliferating B cell follicles were greatly reduced, demonstrating that although BAFF/APRIL is dispensable for B cell development in BM, it is required for B cell development in GALT. We found that all rabbit B cells expressed BAFF receptor 3, but did not bind rBAFF, suggesting that the BAFF-binding receptors (BBRs) are bound by endogenous soluble BAFF. Further, we found that B cells themselves express BAFF, suggesting that the soluble BAFF bound to BBRs may be endogenously produced and stimulate B cells in an autocrine fashion. Additionally, we propose that this chronic occupancy of BBRs on B cells may provide a tonic and/or survival signal for the maintenance of peripheral B cells in adults after B lymphopoiesis is arrested in BM.

| S-EPMC3410555 | biostudies-literature

TCR binding differs for a bacterial superantigen (SEE) and a viral superantigen (Mtv-9).

Project description:Both superantigens (SAG) and many anti-TCR monoclonal antibodies (mAb) have specificity for the V beta region of the TCR encoded by TCRBV genes. For instance the bacterial SAG staphylococcal enterotoxin E (SEE), the retroviral SAG MTV-9 and the mAb OT145 each react with human T cells expressing BV6S7. This BV gene encodes two common alleles. We found that SEE and the mAb preferentially activate T cells expressing BV6S7*1 as opposed to BV6S7*2, but Mtv-9 activates T cells expressing either allele. Thus binding to the TCR differs between the two SAGs. A mutation in the TCR HVR-4 region of BV6S7*1 (G72E), where the two BV6S7 alleles differ, indicated that HVR-4 is a component of the binding site for SEE and for the mAb OT145. BV6S7*2 has a charged E72 which may result in electrostatic repulsion of SEE, as SEE contains a similarly acidic aspartic acid residue at a TCR interaction site (204D).

| S-EPMC2192839 | biostudies-other

High affinity of interaction between superantigen and T cell receptor Vbeta molecules induces a high level and prolonged expansion of superantigen-reactive CD4+ T cells.

Project description:In mice implanted with an osmotic pump filled with the superantigen (SAG) staphylococcal enterotoxin A (SEA), the V?3(+)CD4(+) T cells exhibited a high level of expansion whereas the V?11(+)CD4(+) T cells exhibited a mild level of expansion. In contrast, in mice implanted with an osmotic pump filled with SE-like type P (SElP, 78.1% homologous with SEA), the V?11(+)CD4(+) T cells exhibited a high level of expansion while the V?3(+)CD4(+) T cells exhibited a low level of expansion, suggesting that the level of the SAG-induced response is determined by the affinities between the TCR V? molecules and SAG. Analyses using several hybrids of SEA and SElP showed that residue 206 of SEA determines the response levels of V?3(+)CD4(+) and V?11(+)CD4(+) T cells both in vitro and in vivo. Analyses using the above-mentioned hybrids showed that the binding affinities between SEA and the V?3/V?11 ? chains and between SEA-MHC class II-molecule complex and V?3(+)/V?11(+) CD4(+) T cells determines the response levels of the SAG-reactive T cells both in vitro and in vivo.

| S-EPMC2945535 | biostudies-literature

Gene Expression Changes Induced by Bacterial Superantigen, Staphylococcal Enterotoxin B

Project description:Toxic shock syndrome (TSS) is an acute, serious systemic illness caused by bacterial superantigens (BSAg). We characterized the early molecular events underlying TSS using our HLA-DR3 transgenic mouse model and studied gene expression profiling using DNA microarrays. HLA-DR3 transgenic mice were intraperitoneally treated with either PBS or bortezomib on days -1 and 0. On day 0, each treatment group was further divided in to two groups, one received 10 Î¼g of endotoxin-reduced highly purified SEB and the other PBS alone thus making a total of 4 groups (i.e., PBS+PBS, bortezomib+PBS, PBS+SEB, bortezomib+SEB). Three hours later, mice were euthanized by CO2 asphyxiation, spleens were immediately collected and frozen in liquid nitrogen. Once all the animals had been sacrificed, total RNA from spleens was extracted

2010-03-04 | E-GEOD-15571 | biostudies-arrayexpress

Structural basis of T-cell specificity and activation by the bacterial superantigen TSST-1.

Project description:Superantigens (SAGs) bind simultaneously to major histocompatibility complex (MHC) and T-cell receptor (TCR) molecules, resulting in the massive release of inflammatory cytokines that can lead to toxic shock syndrome (TSS) and death. A major causative agent of TSS is toxic shock syndrome toxin-1 (TSST-1), which is unique relative to other bacterial SAGs owing to its structural divergence and its stringent TCR specificity. Here, we report the crystal structure of TSST-1 in complex with an affinity-matured variant of its wild-type TCR ligand, human T-cell receptor beta chain variable domain 2.1. From this structure and a model of the wild-type complex, we show that TSST-1 engages TCR ligands in a markedly different way than do other SAGs. We provide a structural basis for the high TCR specificity of TSST-1 and present a model of the TSST-1-dependent MHC-SAG-TCR T-cell signaling complex that is structurally and energetically unique relative to those formed by other SAGs. Our data also suggest that protein plasticity plays an exceptionally significant role in this affinity maturation process that results in more than a 3000-fold increase in affinity.

| S-EPMC1852840 | biostudies-literature

Gene Expression Changes Induced by Bacterial Superantigen, Staphylococcal Enterotoxin B

2009-04-09 | GSE15571 | GEO

Cryptopatches are essential for the development of human GALT.

Project description:Abnormal gut-associated lymphoid tissue (GALT) in humans is associated with infectious and autoimmune diseases, which cause dysfunction of the gastrointestinal (GI) tract immune system. To aid in investigating GALT pathologies in vivo, we bioengineered a human-mouse chimeric model characterized by the development of human GALT structures originating in mouse cryptopatches. This observation expands our mechanistic understanding of the role of cryptopatches in human GALT genesis and emphasizes the evolutionary conservation of this developmental process. Immunoglobulin class switching to IgA occurs in these GALT structures, leading to numerous human IgA-producing plasma cells throughout the intestinal lamina propria. CD4+ T cell depletion within GALT structures results from HIV infection, as it does in humans. This human-mouse chimeric model represents the most comprehensive experimental platform currently available for the study and for the preclinical testing of therapeutics designed to repair disease-damaged GALT.

| S-EPMC3725137 | biostudies-literature

Glycosylphosphatidylinositol-Anchored Immunoglobulin Superfamily Cell Adhesion Molecules and Their Role in Neuronal Development and Synapse Regulation.

Project description:Immunoglobulin superfamily (IgSF) cell adhesion molecules (CAMs) are cell surface glycoproteins that not only mediate interactions between neurons but also between neurons and other cells in the nervous system. While typical IgSF CAMs are transmembrane molecules, this superfamily also includes CAMs, which do not possess transmembrane and intracellular domains and are instead attached to the plasma membrane via a glycosylphosphatidylinositol (GPI) anchor. In this review, we focus on the role GPI-anchored IgSF CAMs have as signal transducers and ligands in neurons, and discuss their functions in regulation of neuronal development, synapse formation, synaptic plasticity, learning, and behavior. We also review the links between GPI-anchored IgSF CAMs and brain disorders.

| S-EPMC5715320 | biostudies-literature

Identification of small molecules inhibiting diguanylate cyclases to control bacterial biofilm development.

Project description:Biofilm formation by pathogenic bacteria is an important virulence factor in the development of numerous chronic infections, thereby causing a severe health burden. Many of these infections cannot be resolved, as bacteria in biofilms are resistant to the host's immune defenses and antibiotic therapy. An urgent need for new strategies to treat biofilm-based infections is critically needed. Cyclic di-GMP (c-di-GMP) is a widely conserved second-messenger signal essential for biofilm formation. The absence of this signalling system in higher eukaryotes makes it an attractive target for the development of new anti-biofilm agents. In this study, the results of an in silico pharmacophore-based screen to identify small-molecule inhibitors of diguanylate cyclase (DGC) enzymes that synthesize c-di-GMP are described. Four small molecules, LP 3134, LP 3145, LP 4010 and LP 1062 that antagonize these enzymes and inhibit biofilm formation by Pseudomonas aeruginosa and Acinetobacter baumannii in a continuous-flow system are reported. All four molecules dispersed P. aeruginosa biofilms and inhibited biofilm development on urinary catheters. One molecule dispersed A. baumannii biofilms. Two molecules displayed no toxic effects on eukaryotic cells. These molecules represent the first compounds identified from an in silico screen that are able to inhibit DGC activity to prevent biofilm formation.

| S-EPMC4120261 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

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