Abstract: The present invention provides methods for generating mucosal tissue homing immunosuppressive T-cells comprising treating naïve T-cells with retinoids and/or retinoid agonists. Methods are also provided for treating a mammal having an inflammatory or immunological disease by administering a therapeutically effective dose of retinoids and/or retinoid agonists. Additional methods are also provided for boosting the immune system of a mammal by inhibiting the generation of immunosuppressive T-cells by administering a therapeutically effective dose of a retinoid receptor antagonist to the mammal.