A method and conjugate for selectively killing antigen-activated T cells are disclosed. The conjugate is composed of a substantially uncharged antisense compound targeted against the human cFLIP protein, and a reverse TAT (rTAT) polypeptide coupled covalently to the antisense compound. The rTAT polypeptide is effective to produce selective uptake of the conjugate into antigen-activated T cells, relative to the uptake of the conjugate into non-activated T cells. The cFLIP antisense compound causes activation induced cell death (AICD) of activated lymphocytes. The method is useful in treating transplantation rejection and autoimmune conditions.