Current invention is related to the molecular pharmacology branch particularlyto a peptide belonging to the Interleukin-15 sequence (IL-15) which is able toinhibit IL-15 biological activity, analogues or mimetic of such peptides. Inthecurrent invention it is shown that the peptide inhibits both IL-15-induced Tcells proliferation upon binding to the IL15 receptor a subunit (IL15R.alpha.)andTNF.alpha.-mediated apoptosis.Besides, this invention is related to the use of this peptide in the treatmentofseveral pathologies where aberrant IL-15 or IL-15R.alpha. expression isassociatedto the disease progression.
