The present disclosure relates to a method for the treatment of a non-pathogen associated inflammatory disorders in a subject in need thereof, comprising administering to said subject an isolated peptide which specifically binds to an amino acid sequence within the dimer interface of a T cell costimulatory pathway member, particularly the T cell costimulatory pathway members CD28 and CTLA4. The present disclosure also relates to pharmaceutical compositions comprising the isolated peptide and to use of the peptide in treating of a non-pathogen associated inflammatory disorders.