scholarly journals Inhibition of Nb2 T-lymphoma cell growth by transforming growth factor-β

1988 ◽  
Vol 253 (1) ◽  
pp. 295-298 ◽  
Author(s):  
E J Rayhel ◽  
D A Prentice ◽  
P S Tabor ◽  
W H Flurkey ◽  
R W Geib ◽  
...  
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Interleukin 2 ◽  
Transforming Growth Factor Β ◽  
Tgf Beta ◽  
Inhibitory Effects ◽  
Nb2 Cells ◽  
Growth Factor Beta ◽  
T Lymphoma

Transforming growth factor-beta (TGF-beta) inhibits proliferation of Nb2 cells, a rat T lymphoma, in response to lactogens and interleukin-2. Prostaglandins may play an important role in the pathway through which TGF-beta exerts its inhibitory actions, because prostaglandin E2 also inhibits proliferation of Nb2 cells, and indomethacin, an inhibitor of prostaglandin synthesis, reverses the inhibitory effects of TGF-beta on Nb2 cell proliferation.

scholarly journals Identification of transforming growth factor-beta as a contaminant in factor VIII concentrates: a possible link with immunosuppressive effects in hemophiliacs

Blood ◽  
1994 ◽  
Vol 84 (6) ◽  
pp. 2021-2030
Author(s):  
M Wadhwa ◽  
P Dilger ◽  
J Tubbs ◽  
A Mire-Sluis ◽  
T Barrowcliffe ◽  
...  
Keyword(s):  
T Cells ◽  
Growth Factor ◽  
Factor Viii ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Interleukin 2 ◽  
Contributory Factor ◽  
Tgf Beta ◽  
Factor Viii Concentrates ◽  
Growth Factor Beta

In previous studies, we have shown that some, but not all low-, intermediate-, and high-purity factor VIII concentrates inhibit interleukin-2 (IL-2) secretion from phytohemagglutinin (PHA)-stimulated T lymphocytes. We now present evidence that this inhibitory action of concentrates is, at least in part, due to contamination with transforming growth factor-beta (TGF-beta). Originally identified in platelets, TGF-beta is a 25-kD homodimer that has been shown to be a natural and potent inhibitor of many immunologic responses. Using a specific bioassay, we have measured TGF-beta in various factor VIII concentrates. While some concentrates contained substantial amounts of the cytokine, there was a wide variation in concentrations of TGF-beta in different products. These levels correlated with the degree of inhibition of IL-2 secretion from T cells exhibited by each product (P = .0001). Noninhibitory concentrates contained no detectable TGF-beta. Addition of a specific TGF-beta 1 antibody reversed the inhibitory effect of some concentrates on IL-2 secretion by PHA-stimulated Jurkat T cells and interleukin-5 (IL-5)-induced proliferation of an erythroleukemic cell line. These findings suggest that TGF-beta contamination is a major contributory factor to the inhibitory activity of some factor VIII concentrates on cytokine secretion or activity, and may partially explain the reported immunosuppressive effects in recipients of these blood products.

scholarly journals Transforming growth factor beta inhibits megakaryocyte growth and endomitosis

Blood ◽  
1992 ◽  
Vol 79 (3) ◽  
pp. 619-626 ◽  
Author(s):  
DJ Kuter ◽  
DM Gminski ◽  
RD Rosenberg
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Potent Inhibitor ◽  
Neutralizing Antibody ◽  
Maximal Concentration ◽  
Tgf Beta ◽  
Inhibitory Effects ◽  
Growth Factor Beta

Abstract Using a rat bone marrow culture system, the effect of transforming growth factor beta 1 (TGF beta 1) on megakaryocyte growth and endoreduplication has been studied. Purified human platelet TGF beta 1 inhibited the number of megakaryocytes that appeared in culture at a half-maximal concentration of 0.66 +/- 0.21 ng/mL and inhibited megakaryocyte endoreduplication at a half-maximal concentration of 0.14 +/- 0.08 ng/mL. Under identical conditions, growth of erythroid precursors was half-maximally inhibited at a concentration of 0.125 ng/mL while myeloid growth was not inhibited at concentrations of TGF beta 1 up to 25 ng/mL. These profound inhibitory effects on megakaryocyte growth and endomitosis suggested that TGF beta might play a role in megakaryocytopoiesis. Therefore, we explored the effect of TGF beta in three different experimental situations by using a neutralizing antibody to TGF beta: (1) Serum but not plasma was found to inhibit the number and ploidy of megakaryocytes that grew in vitro. This inhibitory activity was completely neutralized by antibody to TGF beta or on treatment with dithiothreitol. (2) Plasma from thrombocytotic rats was observed to decrease megakaryocyte ploidy on culture but this effect was not prevented by the addition of antibody to TGF beta. (3) Plasma from thrombocytopenic but not normal rats increased megakaryocyte ploidy on culture. Addition of antibody to TGF beta did not alter these results. Therefore, TGF beta is a potent inhibitor of the number and ploidy of megakaryocytes and accounts for all the inhibition seen when megakaryocytes are cultured in serum. However, the differences in effect on megakaryocyte growth that we observe between normal, thrombocytopenic, and thrombocytotic plasmas are not due to variations in the amount of TGF beta. Furthermore, our results show that release of TGF beta from megakaryocytes during culture does not act as an autocrine regulator of megakaryocyte ploidy in vitro.

scholarly journals Transforming growth factor beta inhibits megakaryocyte growth and endomitosis

Blood ◽  
1992 ◽  
Vol 79 (3) ◽  
pp. 619-626 ◽  
Author(s):  
DJ Kuter ◽  
DM Gminski ◽  
RD Rosenberg
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Potent Inhibitor ◽  
Neutralizing Antibody ◽  
Maximal Concentration ◽  
Tgf Beta ◽  
Inhibitory Effects ◽  
Growth Factor Beta

Using a rat bone marrow culture system, the effect of transforming growth factor beta 1 (TGF beta 1) on megakaryocyte growth and endoreduplication has been studied. Purified human platelet TGF beta 1 inhibited the number of megakaryocytes that appeared in culture at a half-maximal concentration of 0.66 +/- 0.21 ng/mL and inhibited megakaryocyte endoreduplication at a half-maximal concentration of 0.14 +/- 0.08 ng/mL. Under identical conditions, growth of erythroid precursors was half-maximally inhibited at a concentration of 0.125 ng/mL while myeloid growth was not inhibited at concentrations of TGF beta 1 up to 25 ng/mL. These profound inhibitory effects on megakaryocyte growth and endomitosis suggested that TGF beta might play a role in megakaryocytopoiesis. Therefore, we explored the effect of TGF beta in three different experimental situations by using a neutralizing antibody to TGF beta: (1) Serum but not plasma was found to inhibit the number and ploidy of megakaryocytes that grew in vitro. This inhibitory activity was completely neutralized by antibody to TGF beta or on treatment with dithiothreitol. (2) Plasma from thrombocytotic rats was observed to decrease megakaryocyte ploidy on culture but this effect was not prevented by the addition of antibody to TGF beta. (3) Plasma from thrombocytopenic but not normal rats increased megakaryocyte ploidy on culture. Addition of antibody to TGF beta did not alter these results. Therefore, TGF beta is a potent inhibitor of the number and ploidy of megakaryocytes and accounts for all the inhibition seen when megakaryocytes are cultured in serum. However, the differences in effect on megakaryocyte growth that we observe between normal, thrombocytopenic, and thrombocytotic plasmas are not due to variations in the amount of TGF beta. Furthermore, our results show that release of TGF beta from megakaryocytes during culture does not act as an autocrine regulator of megakaryocyte ploidy in vitro.

scholarly journals Transforming growth factor beta and cyclosporin A inhibit the inducible activity of the interleukin-2 gene in T cells through a noncanonical octamer-binding site.

1993 ◽  
Vol 13 (2) ◽  
pp. 1155-1162 ◽  
Author(s):  
T Brabletz ◽  
I Pfeuffer ◽  
E Schorr ◽  
F Siebelt ◽  
T Wirth ◽  
...  
Keyword(s):  
Growth Factor ◽  
T Lymphocytes ◽  
Cyclosporin A ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Interleukin 2 ◽  
Tgf Beta ◽  
Enhancer Activity ◽  
Upstream Promoter ◽  
Growth Factor Beta

Transforming growth factor beta (TGF-beta) has a growth-inhibitory effect on numerous different cell types of the immune system, including T lymphocytes. We show in this study that the inhibitory action of TGF-beta on T lymphocytes is accompanied by a block of interleukin 2 (IL-2) gene expression which is mediated, at least in part, by inhibition of IL-2 promoter/enhancer activity. The functional analysis of cis-regulatory (proto-enhancer) elements of the IL-2 enhancer/promoter region showed that the most TGF-beta-responsive element maps to its so-called upstream promoter site. The proto-enhancer activity of the upstream promoter site element is also inhibited by cyclosporin A. The upstream promoter site DNA harbors two noncanonical, closely linked binding sequences for octamer and AP-1-like factors. Both sites are involved in the establishment of IL-2 enhancer activity. Since the activity of genuine octamer sites but not that of AP-1-binding sites is also impaired by TGF-beta and cyclosporin A in El4 T lymphoma cells, we conclude that both immunosuppressives interfere with the activity but not the DNA binding of octamer factors in T lymphocytes.

scholarly journals Identification of transforming growth factor-beta as a contaminant in factor VIII concentrates: a possible link with immunosuppressive effects in hemophiliacs

Blood ◽  
1994 ◽  
Vol 84 (6) ◽  
pp. 2021-2030 ◽  
Author(s):  
M Wadhwa ◽  
P Dilger ◽  
J Tubbs ◽  
A Mire-Sluis ◽  
T Barrowcliffe ◽  
...  
Keyword(s):  
T Cells ◽  
Growth Factor ◽  
Factor Viii ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Interleukin 2 ◽  
Contributory Factor ◽  
Tgf Beta ◽  
Factor Viii Concentrates ◽  
Growth Factor Beta

Abstract In previous studies, we have shown that some, but not all low-, intermediate-, and high-purity factor VIII concentrates inhibit interleukin-2 (IL-2) secretion from phytohemagglutinin (PHA)-stimulated T lymphocytes. We now present evidence that this inhibitory action of concentrates is, at least in part, due to contamination with transforming growth factor-beta (TGF-beta). Originally identified in platelets, TGF-beta is a 25-kD homodimer that has been shown to be a natural and potent inhibitor of many immunologic responses. Using a specific bioassay, we have measured TGF-beta in various factor VIII concentrates. While some concentrates contained substantial amounts of the cytokine, there was a wide variation in concentrations of TGF-beta in different products. These levels correlated with the degree of inhibition of IL-2 secretion from T cells exhibited by each product (P = .0001). Noninhibitory concentrates contained no detectable TGF-beta. Addition of a specific TGF-beta 1 antibody reversed the inhibitory effect of some concentrates on IL-2 secretion by PHA-stimulated Jurkat T cells and interleukin-5 (IL-5)-induced proliferation of an erythroleukemic cell line. These findings suggest that TGF-beta contamination is a major contributory factor to the inhibitory activity of some factor VIII concentrates on cytokine secretion or activity, and may partially explain the reported immunosuppressive effects in recipients of these blood products.

scholarly journals Transforming growth factor beta and cyclosporin A inhibit the inducible activity of the interleukin-2 gene in T cells through a noncanonical octamer-binding site

1993 ◽  
Vol 13 (2) ◽  
pp. 1155-1162
Author(s):  
T Brabletz ◽  
I Pfeuffer ◽  
E Schorr ◽  
F Siebelt ◽  
T Wirth ◽  
...  
Keyword(s):  
Growth Factor ◽  
T Lymphocytes ◽  
Cyclosporin A ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Interleukin 2 ◽  
Tgf Beta ◽  
Enhancer Activity ◽  
Upstream Promoter ◽  
Growth Factor Beta

Transforming growth factor beta (TGF-beta) has a growth-inhibitory effect on numerous different cell types of the immune system, including T lymphocytes. We show in this study that the inhibitory action of TGF-beta on T lymphocytes is accompanied by a block of interleukin 2 (IL-2) gene expression which is mediated, at least in part, by inhibition of IL-2 promoter/enhancer activity. The functional analysis of cis-regulatory (proto-enhancer) elements of the IL-2 enhancer/promoter region showed that the most TGF-beta-responsive element maps to its so-called upstream promoter site. The proto-enhancer activity of the upstream promoter site element is also inhibited by cyclosporin A. The upstream promoter site DNA harbors two noncanonical, closely linked binding sequences for octamer and AP-1-like factors. Both sites are involved in the establishment of IL-2 enhancer activity. Since the activity of genuine octamer sites but not that of AP-1-binding sites is also impaired by TGF-beta and cyclosporin A in El4 T lymphoma cells, we conclude that both immunosuppressives interfere with the activity but not the DNA binding of octamer factors in T lymphocytes.

scholarly journals Identification of a novel transforming growth factor-beta (TGF-beta 5) mRNA in Xenopus laevis.

1990 ◽  
Vol 265 (2) ◽  
pp. 1089-1093 ◽  
Author(s):  
P Kondaiah ◽  
M J Sands ◽  
J M Smith ◽  
A Fields ◽  
A B Roberts ◽  
...  
Keyword(s):  
Growth Factor ◽  
Xenopus Laevis ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Tgf Beta ◽  
Growth Factor Beta

scholarly journals Recombinant type 1 transforming growth factor beta precursor produced in Chinese hamster ovary cells is glycosylated and phosphorylated.

1988 ◽  
Vol 8 (5) ◽  
pp. 2229-2232 ◽  
Author(s):  
A M Brunner ◽  
L E Gentry ◽  
J A Cooper ◽  
A F Purchio
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Chinese Hamster Ovary ◽  
Transforming Growth Factor ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Tgf Beta ◽  
Ovary Cells ◽  
Growth Factor Beta

Analyses of cDNA clones coding for simian type 1 transforming growth factor beta (TGF-beta 1) suggest that there are three potential sites for N-linked glycosylation located in the amino terminus of the precursor region. Analysis of [3H]glucosamine-labeled serum-free supernatants from a line of Chinese hamster ovary cells which secrete high levels of recombinant TGF-beta 1 indicate that the TGF-beta 1 precursor, but not the mature form, is glycosylated. Digestion with neuraminidase resulted in a shift in migration of the two TGF-beta 1 precursor bands, which suggests that they contain sialic acid residues. Endoglycosidase H had no noticeable effect. Treatment with N-glycanase produced two faster-migrating sharp bands, the largest of which had a molecular weight of 39 kilodaltons. TGF-beta 1-specific transcripts produced by SP6 polymerase programmed the synthesis of a 42-kilodalton polypeptide which, we suggest, is the unmodified protein backbone of the precursor. Labeling with 32Pi showed that the TGF-beta 1 precursor was phosphorylated in the amino portion of the molecule.

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