Production of human B and T cell growth factors is enhanced by thymic hormones.
The thymic preparations thymosin fraction 5 (TF5) and synthetic thymosin alpha 1 (T alpha 1) were examined for their ability to enhance growth factor production by human peripheral blood mononuclear cells (PBMC). The results showed that both TF5 and T alpha 1 were capable of enhancing the production of a B cell growth factor (BCGF-12kD) and T cell growth factor (TCGF; IL-2). Enhancement by T alpha 1 could be obtained at 100-200-fold lower concentrations than that seen with TF5. In contrast, no enhancement of growth factor production was obtained with control preparations of non-thymic tissue extracts at any concentrations used. It was observed that stimulation of BCGF-12kD and IL-2 was most significantly obtained when the PBMC were activated with lectin. Furthermore, no direct effect of thymic hormones on test B and T cells was observed. These observations provide the first direct evidence that production of B cell growth factors can be enhanced by thymic hormones. In addition, these studies suggest that thymic hormones may regulate B cell responses by acting on mature activated T lymphocytes.
Kouttab
N M
NM
Department of Pathology, Roger Williams General Hospital, Providence, RI.
Goldstein
A L
AL
Lu
M
M
Lu
L
L
Campbell
B
B
Maizel
A L
AL
D001402:B-Lymphocytes / Q000187:drug effects / Q000276:immunology; D006801:Humans; D066298:In Vitro Techniques; D007376:Interleukin-2 / Q000096:biosynthesis*; D015847:Interleukin-4; D007378:Interleukins / Q000096:biosynthesis*; D007700:Kinetics; D008213:Lymphocyte Activation; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology; D000077596:Thymalfasin; D013947:Thymosin / Q000031:analogs & derivatives / Q000494:pharmacology; D013951:Thymus Hormones / Q000494:pharmacology*
D007376:Interleukin-2; D007378:Interleukins; D013951:Thymus Hormones; C033782:thymosin fraction 5; D015847:Interleukin-4; D013947:Thymosin; D000077596:Thymalfasin