New peptide for treating arthritis - contg. aminoacid sequence comprising epitope of fragment from human collagen

摘要

Peptides of formula R1-Ala-Gly-R2-Gly-Ala-Pro-Gly-R3 (I), their fragments, immunologically active derivs. and pharmaceutically acceptable salts are new. In (I) R1 is H, Gly-Phe-Pro-Gly-Gln-Asp-Gly-Leu-, or Gly-Phe-Ala-Gly-Gln-Ala-Gly-Pro-; R2 is Pro-Lys- or -Ala-Thr-; R3 is H, Glu-Arg or -Arg-Pro. (I) are made by, e.g. enzymatic digestion of collagen; recombinant nucleic acid techniques, or solid-phase chemical synthesis. Antibodies directed against the 316-333 epitope can be mono- or poly-clonal, e.g. antibody C1 from the cell line ECACC 89083001. USE - (I), which are derived from the amino acid sequence 316-333 of the alpha1 (II) chain of collagen, suppress arthritis and synovitis. (I) represent an epitope present on the arthritis-inducing CB11 fragment of human collagen II (HCII) and suppress HCII-stimulated proliferation of sensitised T-cells. Such proliferation can also be suppressed by treatment with antibodies directed against the antigen and such antibodies may be included with (I) in pharmaceutical compsns. In an example, human peripheral blood mononuclear cells were stimulated with native HCII at 10 microg/ml, then cloned by limiting dilution to isolate a clone, C9, specific for HCII. 20000 C9 cells and 50000 autologous mononuclear cells were cultured together in presence of 10 microg/ml HCII and various concns. of (I). After 5 days, DNA synthesis in the T cells was measured by determining incorporation of tritium-labelled thymidine.