Peptide (I) of 5-40 amino acids (aa) derived from a cytokine in which at least one aa has at least one of its atoms spaced a distance (d), evaluated from structural data, less than 5 Å from an atom of the corresponding cytokine receptor is new. Excluded are peptides from between the 2nd and 3rd Cys of RANTES and from residues 123-140 of interferon alpha . Independent claims are also included for: (1) derivatives (Ia) of (I) produced by deletion, substitution, addition, cyclization, stereochemical modification (use of D amino acids) or functionalization (e.g. acylation) of one or more aa and (2) immunogenic compound that comprises (I) or (Ia) provided that is does not contain other cytokine epitopes and can generate antibodies that recognize the native cytokine. ACTIVITY : Immunosuppressive Neuroprotective Antirheumatic Antiarthritic Antipsoriatic Antidiabetic Dermatological Antiinflammatory Antiallergic Antiasthmatic Cytostatic Anti-HIV. MECHANISM OF ACTION : Vaccine. The peptide Leu-His-Leu-Gln-Gly-Gln-Asp-Met-Glu-Gln-Gln (residues 123-132 of human interleukin-1 beta ) was attached to Lys at the N-terminus then coupled to keyhole limpet hemocyanin. The immunogen was administered (with adjuvants) to mice: 40 Microg on day 0 and 20 Microg on each of days 21 and 40. On day 60 antibodies against human IL-1 beta were measured the enzyme-linked immunosorbent assay titer was 1.15, compared with 0.08 in unvaccinated controls. The induced antibodies were neutralizing.