[Analysis of a novel gene expressed in apoptotic T-cell hybridoma treated with dexamethasone]

Developmentally and physiologically controlled cell deaths are called programmed cell death (PCD), and distinguished from accidental cell death while apoptosis is defined morphologically as a certain type of cell death (i.e. chromatin condensation, DNA fragmentation, organella compaction, and blebing of cell and nuclear membranes). Apoptosis is often associated with PCD. Most of cells undergoing PCD have been shown to require de novo synthesis of mRNA and protein. A number of genes have been reported to be expressed in apoptotic cells. In the immune system programmed cell death plays an important role in negative selection of immature T cells. Situations that result in programmed cell death include the withdrawal of cytokine from cultures of cytokine dependent cells, lysis of target cells by cytotoxic T cells, and activation of T cells. In T cells, another well described means of inducing apoptosis is an exposure to glucocorticoids. We cloned a novel gene expressed in apoptotic 2B4. 11 mouse T-cell hybridoma treated with steroid. This gene was not detected in vivo, but was so in mouse thymocytes and splenocytes cultured with dexamethasone and IgM stimulated mouse preB cell line WEHI-231. Thirty-six amino acids, position 2-37, has a 37% homology to mouse intracisternal A-particle gag p27 protein.