Immunopotentation of the IgE Antibody Response by 13-cis-Retinoic Acid

Pretreatment of Balb/c mice per os with 13-cis retinoic acid (13-cRA) in gelatin beadlets potentiated the production of a secondary IgE response to ovalbumin (OA) without a detectable primary response. Dose response experiments indicated that a single feeding of the lower doses (0.3 and 1.5 mg/dose) on day -1 potentiated the production of a low IgE response, whereas pretreatment with the higher concentrations of 13-cRA (3.0 and 6.0 mg/dose) potentiated a higher, sustained response. Pretreatment with 4 doses of 13-cRA on a weekly basis prior to immunization potentiated the production of high sustained secondary titers (titer 360-480) regardless of the concentration of 13-cRA used. These results suggest that 13-cRA has both an immunopotentiating effect and a suppressing effect.