Immunolocalization of transforming growth factor-beta 1 in the bovine adrenal cortex using antipeptide antibodies.
Eight- to 12-amino acid long peptides, representing fragments of transforming growth factor-beta 1 (TGF beta 1) and TGF beta 2 were selected on the basis of their potential immunogenicity and were used to generate polyclonal antibodies. Anti-TGF beta 1-(91-103) antibodies recognized specifically TGF beta 1, prevented TGF beta 1 binding to NRK-49F cells, and neutralized the biological activity of TGF beta 1 in adrenocortical cells (consisting in the inhibition of angiotensin-II-induced cortisol production). Antibodies raised against TGF beta 2-(65-73) appeared to recognize TGF beta 2 with a better affinity than TGF beta 1, but were unable to block the binding of either TGF beta 1 or TGF beta 2 to their receptors or to inhibit their biological activity. These observations are in line with a prominant role of the C-terminal domain of TGF beta 1 in its interaction with its receptor(s) and, hence, in its biological activity. Using anti-TGF beta 1-(91-103) antibodies, we could localize immunoreactive TGF beta 1-like material in the cortex of adult bovine adrenal glands. No reactivity was detected in the capsule or adrenal medulla. The reactivity was maximal in the zona fasciculata/reticularis and weaker in the zona glomerulosa. TGF beta-like material was present in a latent form in the conditioned medium from primary cultures of bovine adrenocortical cells. These cells secreted about 5 ng heat-activatable TGF beta-like material/24 h of culture.10(6) cells. Taken together with our previous reports that bovine adrenocortical cells possess high affinity TGF beta 1 receptors and secrete a TGF beta 1-like molecule under a latent form, the present observations further support the hypothesis that TGF beta 1 or a closely immunologically related protein acts as an autocrine regulator of adrenocortical steroidogenic functions.
Keramidas
M
M
Laboratoire BRCE, Unité INSERM 244, Centre d'Etudes Nucléaires, Grenoble, France.
Bourgarit
J J
JJ
Tabone
E
E
Corticelli
P
P
Chambaz
E M
EM
Feige
J J
JJ
D000302:Adrenal Cortex / Q000737:chemistry* / Q000378:metabolism; D000818:Animals; D000906:Antibodies / Q000276:immunology / Q000494:pharmacology; D000918:Antibody Specificity; D002417:Cattle; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000276:immunology; D006241:Haptens; D006433:Hemocyanins / Q000276:immunology; D006854:Hydrocortisone / Q000096:biosynthesis; D007124:Immunoenzyme Techniques; D010446:Peptide Fragments / Q000276:immunology; D011869:Radioligand Assay; D016212:Transforming Growth Factor beta / Q000032:analysis* / Q000378:metabolism / Q000494:pharmacology; D015383:Zona Fasciculata / Q000737:chemistry; D015384:Zona Glomerulosa / Q000737:chemistry
D000906:Antibodies; D000939:Epitopes; D006241:Haptens; D010446:Peptide Fragments; D016212:Transforming Growth Factor beta; D006433:Hemocyanins; C032808:keyhole-limpet hemocyanin; D006854:Hydrocortisone