Delayed type hypersensitivity, sensitization or maximization studies may be employed to determine if the test article is a dermal sensitizer and if it can suppress an induced DTH reaction. Often called type IV hypersensitivity, DTH reactions are caused by the release of mediators from activated T cells, which in turn activate local endothelial cells and cause swelling and inflammation.
CBI offers expertise in the following DTH studies:
- Skin sensitization (maximization) study using the Beuhler or Magnusson-Kligman method
- Delayed type hypersensitivity study:
- Oxazolone (TH-2 mediated; back skin or ear thickness) The oxalazone-induced delayed type hypersensitivity model (DTH) in the BalbC mouse is a robust and reproducible model for the assessment of T-cell mediated Type 4 immune response. The DTH is induced initially by applying oxalazone to the ear following epicutaneous sensitization.
- TH-1 mediated hapten-induced: DNFB, DNCB, TNFB, TNCB, TMA, etc.
- Back skin or ear thickness
- Intradermal methylated BSA
- Murine local lymph node assay for assessment of allergic contact dermatitis potential
- Passive cutaneous anaphylaxis
- Chemical irritant dermatitis
Endpoints for DTH studies may include:
- Dermal optical coherence tomography (OCT)
- Enzyme-linked immune absorbent assays
- Immunohistochemistry assays
- Laser Doppler for blood flow
- Silhouette photography
- Pharmacokinetic/pharmacodynamic sampling
- Clinical chemistry
- Histopathology by our in-house histology lab