Bacterial Toxin Research Citations

Cells and reagents:

… Escherichia coli LPS 0111:B4 was purchased from List Biological Laboratories, …

… On day 4, the BM cells were treated with 0 or 50 mM EtOH for another 5 days. On day 9, the cell density was regulated to 1 10⁶/ml/well in 24-well plates. After culturing overnight, medium was changed and cells were incubated for additional 6 h with 0 or 100 ng/ml LPS (E. coli 0111:B4; List Biological Laboratories). …

TNF- mRNA half-life assay:

A total of 1 g/ml actinomycin was added to the culture at 0, 30, and 60 min after stimulation with LPS/PMA. Mono Mac 6 cells were collected at each time point and TNF- mRNA was measured by real-time PCR described previously.

Chromatin IP (ChIP) assay for human IRF-3:

Mono Mac 6 cells culture in control or EtOH conditions were plated to 24-well plate at a cell density of 2 10⁶ of cells/ml/well, and stimulated with LPS and PMA for 1 h as stated above. Then the cells were crosslinked with 1% (v/v) formaldehyde at 37C for 20 min. …

Cell transduction with lentivirus and luciferase assay:

… BM cells were transduced overnight by lentivirus with ISRE, AP-1 driving luciferase as a reporter on day 3 before treating EtOH, and followed with EtOH and LPS as described above. After stimulation by LPS/PMA (for Mono Mac 6 cells) or LPS (for BM cells) for 6 h, the cells were harvested and ISRE, AP-1, or TNF- promoters activities were analysis using the Luciferase Reporter Assay System (Promega). The luciferase activities were normalized by total cellular proteins. …

• Product #201 – LPS from Escherichia coli O111:B4

Materials:

SNAPtide substrates (Product # 520), Botulinum Neurotoxin Type A (Product #130A) and Botulinum Neurotoxin Type B (Product #136) are products of List Biological Laboratories.

• Product #520 – SNAPtide Peptide Substrate (o-Abz/Dnp) for C. botulinum Type A Neurotoxin
• Product #130A – Botulinum Neurotoxin Type A from Clostridium botulinum
• Product #136 – Botulinum Neurotoxin Type B, Nicked, from Clostridium botulinum

Methods – The above materials were used in the following (refer to poster for details):

• Sandwich ELISA assay showing specificity of BTA for binding to GST-SV2c
•  GST Pull Down Assay
• Dynabead Experiment
• Immobilized Protein G Experiment

Microinjection of Toxin Proteins and Use of Inhibitors:

… LF was purchased from List Laboratories, Inc. …

Author did not indicate which specific lethal factor was utilized.  List Labs provides Product #172 (Anthrax Lethal Factor (LF), Recombinant from B. anthracis) and Product #169L (Anthrax Lethal Factor (LF-A), Recombinant from B. anthracis Native Sequence).

New High Affinity Antibodies Against Botulinum Neurotoxin Type A:

… To test the affinity purified antibodies we determined the titer of the anti-HccA antibodies against Botulinum Neurotoxin Type A (BTA) holotoxin, List Product #130. The ability of the anti-HccA antibodies to capture BTA was also tested using a Sandwich ELISA.

Comparison of FRET Substrates for Botulinum Neurotoxin Type A:

A new FRET substrate for the  zinc endoprotease activity of the 50 kDa light chain (LcA) of the type A Botulinum neurotoxin has been designed and evaluated. This new substrate, which contains the FRET pair Mca/Dnp was compared to the SNAPtide substrate (Product #520 and #521) FRET peptides, which contain the oAbz/Dnp and FITC/DABCYL FRET pairs, respectively …

• Product #130 – Botulinum Neurotoxin Type A from Clostridium botulinum
• Product #520 – SNAPtide Peptide Substrate (o-Abz/Dnp) for C. botulinum Type A Neurotoxin
• Product #521 – SNAPtide Peptide Substrate (FITC/DABCYL) for C. botulinum Type A Neurotoxin

Reagents:

LPS was from List Biological Laboratories (Campbell, CA) …

Results – Monocytes of cHCV patients lack tolerance to TNF -inducing TLR ligands:

… Monocytes of controls and HCV patients were primed in vitro with LPS, a TLR4 ligand, and re-stimulated with LPS to assess homotolerance. In agreement with previous reports (8,9), we found that LPS priming lead to low TNF production in response to a re-challenge with LPS in normal monocytes (Fig 1A). However, homo-tolerance to TLR4 ligand was not found in monocytes from HCV patients (Fig 1B). We further identified that pretreatment with LPS induced hetero-tolerance to subsequent stimulation with TLR2 (PGN), TLR2/TLR6 (PAM₃CSK₄), TLR2/TLR1 (PAM₂CSK), TLR3 (poly I:C) and TLR7/8 (Gardiquimod) ligands in controls (Fig 2A), and in patients with liver inflammation due to non-viral non-alcoholic steatohepatitis (NASH) (Fig 2C) but not in HCV-infected patients (Fig 2B). This data indicated that monocytes of HCV-infected patients have lost TLR tolerance.

Author did not specify which List Labs LPS product was utilized in their research.  List Labs provides the following LPS products:  https://listlabs.com/product-information/lipopolysaccharides/

Quantification of PA₈₃ bound to chimeras 206 and 264:

Recombinant PA₈₃ (List Biological Laboratories) in 5 mM Hepes, 50 mM NaCl (pH 7.5) was mixed with purified chimeras 206 and 264 in 50 mM Hepes (pH 7.5) in a ratio of 180:1 (equimolar amounts of PA₈₃and VWA domains). Following incubation for 20 min at room temprature, an aliquot from each of the samples was removed and stored at 20 C pending analysis. The remainder of the samples was transferred to an ultracentrifuge tube and underlayed with a 30% (w/w) sucrose cushion in 50 mM Hepes (pH 7.5). Complexes of chimeras decorated with PA₈₃ were pelleted by centrifugation at 200,000g for 45 min. …

• Product #171 – Anthrax Protective Antigen (PA), Recombinant from B. anthracis

…Recombinant B. anthracis lethal factor (rLF) and protective antigen (rPA) were acquired from List Biological Laboratories, Inc. (Campbell, CA) …

Author did not indicate which specific lethal factor was utilized.  List Labs provides Product #172 (Anthrax Lethal Factor (LF), Recombinant from B. anthracis) and Product #169 (Anthrax Lethal Factor (LF-A), Recombinant from B. anthracis Native Sequence).

• Product #171 – Anthrax Protective Antigen (PA), Recombinant from B. anthracis

CTb injections into the VTA

The retrogradely transported marker CTb (List Biological Laboratories, Campbell, CA, USA) was unilaterally injected by iontophoresis into the VTA of 16 rats. CTb is considered to be a very sensitive retrograde tracer when visualized by immunohistochemistry. It is taken and retrogradely transported by all neurons of the central nervous system and, unlike viral tracers, not transported transynaptically (Luppi et al., 1990). Animals were anaesthetized with chloral hydrate (400 mg/kg, i.p.) and placed in a stereotaxic frame (David Kopf Instruments, South Natick, MA, USA) with the incisor bar set at −3.3 mm; body temperature was maintained at 37°C using a homeothermic heated pad (Harvard Apparatus, Edenbridge, UK). A hand drill was used to expose the brain surface above the VTA and a borosilicate glass micropipette (tip diameter 5–10 μm) filled with a low-salt CTb solution (0.5% made in 0.1 M phosphate buffer, pH 6.0) was lowered into the brain at the following stereotaxic coordinates: AP, −5.5 mm from bregma; L, −0.7 mm from the midline; and V −7.2 mm from the dural surface (Paxinos & Watson, 2005). CTb was delivered by applying positive pulses of 1–4 μA (7 s on, 7 s off) for 10 min through a chlorinated silver wire placed in the micropipette and connected to a current generator (Bionic Instruments, France). The micropipette was withdrawn 10 min after the CTb ejection, the scalp incision was sutured and rats were returned to their home cages for recovery.

• Product #104 – Cholera Toxin B Subunit (Choleragenoid) from Vibrio cholerae in Low Salt

Cholera toxin (CT) was purchased from List Biological Laboratories Inc. (Campbell, CA, USA).

• Product #100B – Cholera Toxin (AZIDE-FREE) from Vibrio cholerae

The following FRET peptides have been designed at List Biological Laboratories as substrates for the botulinum toxin enzymes. SNAPtide, Product #520 and #521 (U.S. Patent, No. 6,504,006 ) is readily recognized and cleaved by the Botulinum toxin type A (BTA), Product #130, and the BTA light chain (LcA), Product #610A. One of the substrates, Product #520, contains an oAbz/DNP FRET pair and the other, Product #521, a FITC/DABCYL FRET pair. Representative data are given below. VAMPtide, Product #540 is readily recognized and cleaved by the Botulinum toxin type B light chain (LcB), Product #620A. This FRET substrate contains an oAbz/DNP FRET pair. SNAP Etide, Product # 550 is readily recognized and cleaved by the Botulinum toxin type E light chain (LcE), Product #635A. This FRET substrate contains an oAbz/DNP FRET pair.

• Product #520 – SNAPtide Peptide Substrate (o-Abz/Dnp) for C. botulinum Type A Neurotoxin
• Product #521 – SNAPtide Peptide Substrate (FITC/DABCYL) for C. botulinum Type A Neurotoxin
• Product #130 – Botulinum Neurotoxin Type A from Clostridium botulinum
• Product #610A – Botulinum Neurotoxin Type A Light Chain, Recombinant
• Product #540 – VAMPtide Peptide Substrate (o-Abz/Dnp) Substrate for C. botulinum Type B Neurotoxin
• Product #620A – Botulinum Neurotoxin Type B Light Chain, Recombinant
• Product #550 – SNAP Etide Peptide Substrate (o-Abz/Dnp) for C. botulinum Type E Neurotoxin
• Product #635A – Botulinum Neurotoxin Type E Light Chain, Recombinant

(LF) is the enzymatic component of anthrax lethal toxin which specifically cleaves the MAPK-kinase proteins. LF is also an ideal target for therapeutic inhibitors. FRET substrates for LF, MAPKKide, Product #530 and 531, have been designed at List Biological Laboratories. One of the substrates, Product #530, contains an oAbz/DNP FRET pair and the other, Product #531, a FITC/DABCYL FRET pair. Product #531 is especially well suited for high throughput screening for the IC50 and inhibitor modality of potential inhibitors.  …

• Product #530 – MAPKKide Peptide Substrate (o-Abz/Dnp) for Anthrax Lethal Factor
• Product #531 – MAPKKide Peptide Substrate (DABCYL/FITC) for Anthrax Lethal Factor