The immunosuppressory and adhesive miniregion of the human major histocompatibility protein, human leukocyte antigen DQ

✍ Scribed by Z. Szewczuk; P. Stefanowicz; A. Wilczyński; I. Z. Siemion; C. S. Cierniewski; U. Kralisz; Z. Wieczorek

• Publisher: Wiley (John Wiley & Sons)
• Year: 1996
• Tongue: English
• Weight: 830 KB
• Volume: 40
• Category: Article
• ISSN: 0006-3525
• DOI: 10.1002/(sici)1097-0282(1996)40:5<571::aid-bip15>3.0.co;2-k

✦ Synopsis

Our previous studies showed that the nonapeptide fragment of human leukocyte antigen DQ with the TPQRGDWT sequence strongly suppresses the immune response ' [Z. Szewczuk, I. Z. Siemion, and Z. Wieczorek (1996) Molecular Immunology, 33, 903-9081, The fragment contains the RGDW sequence, which is very similar to thymopentin (pentapeptide RKDW, an active fragment (32-36) of thymopoietin, an immune system activator produced in thymi), and at the same time contains the RGD sequence, known as an inhibitor of adhesion processes. In the present study we tested an injuence of the nonapeptide and its shorter fragments on binding of activated platelets and KS62 cells to fibrinogen and fibronectin, respectively. We also designed and synthesized a cyclic thymopentin-like peptide, C *RGDVYC * (where C * indicates Cys participating in disuljide bridge) to restrict its conformation. The cyclization product strongly suppresses the humoral and cellular immune response and selectively inhibits the adhesion of KS62 cells to fibronectin. The results are discussed in the light of CD conformational studies. 0