H3D has a dedicated TB biology team housed at the Institute of Infectious Disease and Molecular Medicine (IDM) with access to BSLII and BSLIII facilities.
The TB biology team routinely conducts whole-cell and target-based screening, biology triaging, target identification and validation studies for the TB projects. The BSLII Drug Discovery Lab houses a separate access-controlled tissue culture facility, the TB screening platform; and bench space for assay development and target ID/mechanism of action work.
See the table below for additional details, including average turnaround time and control(s). For assays where an average turnaround time/control(s) are not available, this indicates that turnaround time is dependent on your unique experimental design and conditions; please book a consultation for an estimated turnaround time.
H3D's expertise and experience is especially pronounced in the following TB Biology areas (see also chart and references below):
Phenotypic Screening
The H37Rv strain is the most commonly used M. tuberculosis strain in labs worldwide and is used by H3D for many TB biology assays. Screening in both non-resistant and resistant strains is available. "Drug resistant strains" of TB are resistant to at least one first line drug used for TB treatment.
TB is currently treated with several antimicrobial drugs simultaneously, and these include isoniazid (INH), rifampin (Rif), pyrazinamide, and ethambutol (Eth). Investigating a compound's activity and efficacy in relation to multiple of these established treatments is critical to developing a competitive drug candidate for treating tuberculosis.
- Single Point Inhibition Assay
- Routine TB MIC Assay (3 media*)
*The inhibitory activity of several compounds has been shown to be impacted by the media composition in which assays are performed. The 3 media compositions utilized allow us to compare the role of defined parameters on compound activity i.e. the effect of detergent and protein/serum binding.
- Non-replicating
TB has both replicating and non-replicating stages, and it is critical to evaluate a drug candidate in both
- Erdman: Highly virulent TB strain
- Screening against single drug resistant (SDR) strains:
- INH-R: Isoniazid resistant
- Rif-R: Rifampin resistant
- DCS-R: D-cycloserine resistant
- Moxi-R: Moxifloxacin resistant
- Eth-R: Ethionamide resistant
Target Based Screening
Target based screening approaches are available for the following M. tuberculosis targets
- PrecA and PiniB lux assay
Luminescence reporter assays reporting on DNA and cell wall damage respectively
- QcrB MIC assay
QcrB is the cytochrome b subunit of the cytochrome bc1 complex. The assay utilizes a QcrB mutant strain and the CydA (cytochromebd menaquinol oxidase) mutant strain which is hyper-sensitive to QcrB inhibitors
- DprEl-mutant: Pentose-reductase related mutant
- MMPL3 assay MIC: Inner membrane transporter from the Mycobacterial Membrane Protein Large (MmpL) family
- ClpP1P2 Assay: ClpP1P2 is a 300-kDa protease from Mycobacterium tuberculosis
Additional TB Biology Assays
- Time-Kill Kinetics
Anti-TB drugs differ significantly regarding their time-kill kinetics, and time-kill kinetics assays are an important part of preclinical modeling framework for assessing the activity of anti-tuberculosis drugs
- Spontaneous Resistant Mutants (SRMs)
Drug-resistant TB is one of the leading causes of death worldwide and arises mainly from spontaneous mutations. SRM generation aids in the deconvolution of the mechanism of action of compounds and allows for the in vitro determination of the frequency of resistance development to compounds
Data from these assays can be used for lead optimization and drug candidate evaluation and results from these assays thereby inform key decision making and experimental design of human and/or animal in vivo studies.
Assay Group | Assay Specifications |
---|---|
Phenotypic Screening | |
TB Screening | Single Point MIC Assay (3 media) |
TB Screening MIC90 | Routine TB MIC Assay (3 media) |
TB Screening MIC90 | Non-replicating |
TB Screening MIC90 | Erdman MIC |
Screening Against Single-Drug Resistant (SDR) Strains | |
TB Screening MIC90 | INH-R MIC |
TB Screening MIC90 | Rif-R MIC |
TB Screening MIC90 | DCS-R MIC |
TB Screening MIC90 | Moxi-R MIC |
TB Screening MIC90 | CydA-mutant MIC |
TB Screening MIC90 | EthA-mutant MIC |
Target Based Screening | |
TB Screening MIC90 | PrecA & PiniB lux MIC Assay |
TB Screening MIC90 | QcrB assay MIC |
TB Screening MIC90 | DprEl assay MIC |
TB Screening MIC90 | MMPL3 assay MIC |
Additional TB Biology Assays | |
Time-Kill Kinetics | |
Spontaneous Resistant Mutants | |
ClpP1P2 Assay |