Immunoregulating peptides II. In vitro effects of TP5 analogs on E-rosette formation and cell division.
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.
Denes
L
L
Chemical Works of Gedeon Richter, Ltd., Budpest, Hungary.
Szende
B
B
Ember
J
J
Major
J
J
Szporny
L
L
Hajos
G
G
Nyeki
O
O
Schon
I
I
Lapis
K
K
Kisfaludy
L
L
D000276:Adjuvants, Immunologic / Q000138:chemical synthesis / Q000276:immunology / Q000494:pharmacology; D001172:Arthritis, Rheumatoid / Q000276:immunology; D002455:Cell Division; D006801:Humans; D066298:In Vitro Techniques; D008214:Lymphocytes / Q000187:drug effects / Q000276:immunology; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000276:immunology; D012397:Rosette Formation; D016305:Thymopentin; D013946:Thymopoietins / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000276:immunology; D013951:Thymus Hormones
D000276:Adjuvants, Immunologic; D010446:Peptide Fragments; D013946:Thymopoietins; D013951:Thymus Hormones; D016305:Thymopentin