Differential inhibition of primary versus preactivated T cells by pimecrolimus but not by tacrolimus in vitro.

Background: Recent studies in murine models of allergic contact dermatitis have shown that systemic treatment with pimecrolimus in contrast to tacrolimus did not inhibit the sensitization phase, whereas both compounds equivalently suppressed the inflammatory response in sensitized animals. This finding indicated a differential sensitivity of antigen-naïve and primed T cells towards pimecrolimus and tacrolimus.

Methods: T cells obtained from healthy and allergic donors were subjected to primary and secondary stimulation by allogeneic or staphylococcal superantigen-presenting dendritic cells (DC).