Peptide-like compounds and their variants having immunomodulating activity including the N-terminal acylated and/or C-terminal amidated or esterified forms thereof of up to 60 amino acids wherein the peptide-type compound comprises the formula:

-

• wherein:
  • and are the same or different and are of the formula:

    {R aa^76-77 L}(aa^79-84)(SEQ ID NO:1)   (a)

    or

    (aa^84-79){L aa^77-76 R}(SEQ ID NO:2)   (b)

• wherein:
  • aa⁷⁶ is E or V;
  • aa⁷⁷ is D, S or N;
  • aa⁷⁹ is R or G;
  • aa⁸⁰ is I or N;
  • aa⁸¹ is a hydrophobic or small amino acid;
  • aa⁸² is R or L;
  • aa⁸³ is G or R;
  • aa⁸⁴ is a hydrophobic or small amino acid;
• wherein
  • the sequence in the brackets may optionally be absent or truncated at any peptide type bond within the brackets may be used by themselves or in combination with immunosuppressant drugs, to reduce CTL activation, particularly in association with transplantation.