Immunomodulators

A substance which is

• (I) a polypeptide amounting to 9 to 100 amino acids, said polypeptide comprising the following sequence:
• X1—X2—X3-Thr-X4-Lys-X5-Arg-X6 (SEQ ID NO:22),
• wherein
• X1 is Ala or Gly,
• X2 is Tyr or Phe,
• X3, X4 and X5 are independently selected from the group consisting of Met, Ile, Leu and Val;
• and
• X6 is selected from the group consisting of Asn, Asp, Gln and Glu,
• and which polypeptide has one or more of the following properties:
• (a) induces inhibition of spontaneous IL-8 production by human monocytes,
• (b) induces inhibition IL-1β induced IL-8 production by human peripheral blood mononuclear cells,
• (c) induces production of interleukin-1 receptor antagonistic protein (IRAP) by human monocytes,
• (d) induces chemotactic migration of CD8+ human T lymphocytes in vitro,
• (e) desensitizes human CD8+ T cells resulting in an unresponsiveness towards recombinant human IL-10 (rhIL-10),
• (f) suppresses the chemotactic response of CD4+ human T lymphocytes towards IL-8,
• (g) suppresses the chemotactic response of human monocytes towards MCAF/MCP-1,
• (h) induces the production of IL-4 by cultured normal human CD4+ T cells, or
• (i) reduces the TNFα production in human mixed leukocyte reaction, or,
• (II) a salt, ester or a conjugate of said polypeptide, but said conjugate is not IL-10 or a fragment of IL-10 which amounts to more than 100 amino acids of IL-10.