Immunoregulating peptides II. In vitro effects of TP5 analogs on E-rosette formation and cell division.

L. Denes, B. Szende, J. Ember, J. Major, L. Szporny, G. Hajos, O. Nyeki, I. Schon, K. Lapis, L. Kisfaludy

Research output: Article


The effects of seventeen synthetic analogs of thymopentin (TP-5) have been studied in the active and azathioprine-inhibited E-rosette tests. Thymopentin was gradually shortened from the C terminus to peptides and single amino acids. Thymopoietin 32-34 (Arg-Lys-Asp-RGH-0205-TP-3) (II) and thymopoietin 32-35 (Arg-Lys-Asp-Val-RGH-0206-TP-4) (I) were the most active peptides. Dipeptide Arg-Lys produced significant stimulatory effect on azathioprine (ED75) inhibited E-receptor. Treatment of azathioprine (ED75)-inhibited E-rosette forming cells (ERFC) with arginine or especially lysine increased the number of ERFC. Some of TP-4 analogs decreased further the number of ERFC decreased by azathioprine ED30. These "suppressive" peptides as well as TP-3 caused a partial arrest of K 562 cell proliferation up to 96 hours. Results suggest that TP-5 is not the smallest active fragment of thymopoietins, since peptides (TP-3 and TP-4) exhibit similar or higher T-cell membrane activation on E-receptor. Arginine, lysine, and acidic aspartyl residue seem to be a necessary basic structure to produce a cumulative chemical signal on the activity of T-lymphocytes.

Original languageEnglish
Pages (from-to)1-18
Number of pages18
JournalImmunopharmacology and Immunotoxicology
Issue number1
Publication statusPublished - 1987


ASJC Scopus subject areas

  • Health, Toxicology and Mutagenesis
  • Immunology
  • Pharmacology
  • Toxicology

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