Rationale:

This assay is another way to assess cell-mediated immune response. It is a Th-1 type model that is employed for evaluating T cell component of the cell-mediated immune response. The sensitization phase is initiated by immunization of experimental mice with a specific protein antigen (mBSA), which is delivered intra-dermally as emulsion with complete Freund¡¦s adjuvant (CFA). The elicitation phase of the reaction, which is triggered by a second intradermal injection of mBSA into the hind paws or ears of the immunized animals (recall), results in the a local inflammation that is measured 24 hours after the recall and expressed as footpad or ear swelling.

Methods:

On day 0 of the experiment, the mice were immunized by s.c. injections of an mBSA/CFA emulsion (125µg mBSA for each site). On day 8 of the experiment, the mice were challenged by s.c. injection of 100 µg of mBSA in 20µl of PBS in the plantar surface of the left hind paw. The contra-lateral paw was injected with the same volume of saline alone. The footpad thickness of each paw was measured by a constant-tension spring-loaded caliper on days 9, 10, and 11 of the experiment. The difference in the thickness between the mBSA-challenged and saline-injected paws was calculated and defined as swelling.