Establishment of a Murine Desensitization Model to PLA2-induced Anaphylaxis

Abstract

Background: The major allergen in honeybee venom is the enzyme phospholipase A2 (PLA2). To develop new treatments for honeybee venom allergy, it is necessary to elucidate the mechanism underlying allergen immunotherapy. In this study, we first created a PLA2 mouse model of honeybee venom anaphylaxis and then established its desensitized model.

Method: Balb/c mice were subcutaneously sensitized four times with PLA2. Blood was collected before sensitization and serum PLA2-specific IgE antibodies were analyzed by enzyme-linked immuno-sorbent assay (ELISA). Rectal temperature was measured before and 30 min after subcutaneous challenge with PLA2, and blood histamine concentration was measured 30 min after that by ELISA. In addition, the PLA2 mouse model of anaphylaxis was desensitized a total of 20 times over 4 weeks, and rectal temperature and blood histamine concentration were measured before and/or 30 min after subcutaneous challenge with PLA2.

Results: After the second sensitization in the PLA2 mouse model of anaphylaxis, a significant increase in serum PLA2-specific IgE antibody was observed compared with the control group. There was a significant decrease in rectal temperature and an increase in histamine levels in the model mice compared with the controls. In addition, there was no decrease in rectal temperature before and after the challenge with PLA2 in the desensitized mice model, and a decrease in histamine levels in the desensitized mice model compared with that in the non-desensitized one.

Conclusion: We have created a PLA2-desensitized mouse model of anaphylaxis in this study. This model is expected to be useful for an immunological analysis of the response mechanism underlying allergen immunotherapy as well as basic research aimed at developing new treatments.