title: Defective calcium-dependent signal transduction in T lymphocytes of ataxia-telangiectasia.
abstract: T-cell functions of two patients with ataxia-telangiectasia were investigated. Patients with ataxia-telangiectasia had reduced percentages of circulating CD3+ cells and CD4+ cells, although neither patient had a reduced percentage of circulating CD8+ cells. The proliferative responses and interleukin-2 production of peripheral blood mononuclear cells to T-cell mitogens were reduced in the patients. The intracellular calcium concentration in T cells or CD4+ cells from both patients was only slightly increased after phytohaemagglutinin stimulation. Moreover, the concentration after OKT3 stimulation was not or only slightly increased in T cells or CD4+ cells from both patients. Our results suggest that the functional defect of T cells is caused by defective Ca(2+)-dependent signal transduction through the CD3 complex of the surface in T cells of ataxia-telangiectasia.
authors.affiliation: Department of Pediatrics, Gifu University School of Medicine, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Kondo
authors.forename: R
authors.initials: R
authors.lastname: Inoue
authors.forename: S
authors.initials: S
authors.lastname: Nishimura
authors.forename: K
authors.initials: K
authors.lastname: Kasahara
authors.forename: T
authors.initials: T
authors.lastname: Kameyama
authors.forename: Y
authors.initials: Y
authors.lastname: Miwa
authors.forename: P R
authors.initials: PR
authors.lastname: Lorenzo
authors.forename: T
authors.initials: T
authors.lastname: Orii
mesh_terms: D000293:Adolescent; D001260:Ataxia Telangiectasia / Q000276:immunology*; D017252:CD3 Complex / Q000032:analysis; D015704:CD4 Antigens / Q000032:analysis; D002118:Calcium / Q000032:analysis / Q000378:metabolism*; D002648:Child; D005260:Female; D006801:Humans; D007376:Interleukin-2 / Q000032:analysis; D008297:Male; D016853:Muromonab-CD3 / Q000494:pharmacology; D010835:Phytohemagglutinins / Q000494:pharmacology; D015398:Signal Transduction / Q000276:immunology*; D013601:T-Lymphocytes / Q000187:drug effects / Q000378:metabolism*
chemical_list: D017252:CD3 Complex; D015704:CD4 Antigens; D007376:Interleukin-2; D016853:Muromonab-CD3; D010835:Phytohemagglutinins; D002118:Calcium