Peptide of a size comprised between 5 and 40 amino acids, originating from a cytokine, in which at least one of its amino acids comprises at least one of its atoms separated by a distance d of less than 5 angströms from an atom of the receptor corresponding to said cytokine, the spacing d being evaluated on the basis of structural data, derivatives, immunogenic compounds comprising them, use of a peptide or peptide derivative or immunogenic compound for the preparation of a curative or preventative medicament intended for the treatment or prevention of diseases linked to an excess or to the presence of cytokines or for the treatment of an auto-immune disease and pharmaceutical compositions which contain at least one abovementioned peptide or peptide derivative or immunogenic compound as active ingredient.