Culture and characterization of thymic epithelium from autoimmune NZB and NZB/W mice.

Autoimmune NZB and NZB/W mice display early abnormalities in thymus histology, T cell development, and mature T cell function. Abnormalities in the subcapsular/medullary thymic epithelium (TE) can also be inferred from the early disappearance of thymulin from NZB. It has also been reported that NZB thymic epithelial cells do not grow in culture conditions that support the growth of these cells from other strains of mice.

Thymocytes stimulate metabolism of arachidonic acid in rat thymic epithelial cells.

Arachidonic acid metabolites play an important role in the development of T cells in the thymus. In the normal animal, prostaglandin levels in the thymus are significantly higher than in plasma. Herein, we have studied the regulation of arachidonic acid metabolism using the thymic endocrine epithelial cell line, TEA3A1, and thymocytes.

Lipocortin-independent effect of dexamethasone on phospholipase activity in a thymic epithelial cell line.

In the cloned rat thymic endocrine epithelial cell line TEA3A1, treatment with dexamethasone leads to decreased levels of prostaglandin E2, prostaglandin F2 alpha, and thromboxane B2. Dexamethasone treatment also leads to a decrease of both calcium-dependent and calcium-independent phospholipase A2 activity measured in a cell-free assay. Dexamethasone-treated cells also have increased levels of lipocortin-I, a putative modulator of phospholipase A2 activity.

A cloned rat thymic epithelial cell line established from serum-free selective culture.

A serum-free system has been developed for selective growth and long-term culture of rat thymic epithelial cells. The growth media is a modification of McKeehan's WAJC 404, plus insulin, cholera toxin, dexamethasone, and epidermal growth factor. Cultures have been continuously passaged and maintained for over 6 mo.

Histological distribution of the 35-KD protein substrate of the epidermal growth factor receptor/kinase in thymus.

Rat thymus has been identified as a tissue comparatively enriched in a 35-KD substrate of the epidermal growth factor receptor/kinase (lipocortin-1) (J Biol Chem 261:13784, 1986). A polyclonal antiserum prepared against the 35-KD protein was used to determine histological distribution of the protein in thymus. Frozen sections of rat thymus were examined after indirect labeling of the 35-KD protein with a rhodamine conjugate of secondary antibody.

EGF receptors on TEA3A1 endocrine thymic epithelial cells.

Thymic endocrine epithelial cell line TEA3A1 can be maintained and passaged in a serum-free WAJC404A medium supplemented with insulin, transferrin, dexamethasone and EGF. EGF not only promotes the growth of these cells but also regulates the activation of phospholipase A2 enzyme activity. The binding of [125I]EGF to the TEA3A1 cells is temperature and time dependent, saturable and can be blocked by excess unlabelled EGF.

Characterization of the gamma subunits of the 7S nerve growth factor complex.

The gamma subunits of the 7S nerve growth factor complex (7S NGF) display arginine esteropeptidase activity. By varying the conditions of electrophoresis in acrylamide gel, it has been demonstrated that the gamma-subunit fraction of 7S NGF contains five different proteins, in contrast to the three (gamma1, gamma2, and gamma3) originally described (Smith, A.P.