Thymopentin induces release of ACTH-like immunoreactivity by human lymphocytes.
Peripheral mononuclear (PMN) cells are known to produce ACTH-like immunoreactivity (ACTH-LIR) in vitro. Based on these findings the aim of this study was to find out whether thymopentin (the active pentapeptide of the native hormone thymopoietin) may stimulate ACTH-LIR production and release by cultured normal human lymphocytes. Thymopentin at concentration of 1 microgram/ml was capable of inducing ACTH-LIR release by normal human PMN cells (median 22 pg/ml) whereas ACTH-LIR inside cells was lower (median 11 pg/10(7) cells). The chromatographic characterization of the eluted material identified the presence of ACTH immunoreactive peptides with the elution characteristics of the precursors 31 K proopiomelanocortin, 22 K ACTH and 4.5 K ACTH, together with higher molecular weight material (greater than 43 K). These data demonstrate that thymopentin induces ACTH-LIR release by human lymphocytes, thus adding a novel factor to those already reported (corticotrophin releasing factor, lipopolysaccharide, viruses) capable of such function.
Buzzetti
R
R
Patologia Medica I, University of Rome, La Sapienza, Italy.
Valente
L
L
Barletta
C
C
Scavo
D
D
Pozzilli
P
P
D000324:Adrenocorticotropic Hormone / Q000096:biosynthesis*; D002478:Cells, Cultured; D006801:Humans; D008214:Lymphocytes / Q000378:metabolism*; D010446:Peptide Fragments / Q000502:physiology*; D011863:Radioimmunoassay; D016305:Thymopentin; D013946:Thymopoietins / Q000502:physiology*; D013951:Thymus Hormones / Q000502:physiology*; D013997:Time Factors
D010446:Peptide Fragments; D013946:Thymopoietins; D013951:Thymus Hormones; D000324:Adrenocorticotropic Hormone; D016305:Thymopentin