Induction of apoptosis in hematopoietic cells with an antibody against tomoregulin-1.
Tomoregulin-1, a type-I transmembrane protein with two follistatin modules, a unique epidermal growth factor (EGF) domain and a short, highly conserved cytoplasmic tail, was studied. A number of hematopoietic cell lines (L1210, CEM, Jurkat, U937, K562, JY, THP-1 and T2) express tomoregulin-1 endogenously. In these cells, apoptosis was induced by an antiserum (C29) and purified IgG against the follistatin modules, but not by antisera against the EGF-domain or the cytoplasmic tail. Furthermore, C29 induced apoptosis in tomoregulin-1-, but not in mock-transfected cells. Apoptosis was monitored through genomic DNA fragmentation, annexin-V staining and caspase-3 activation. Treatment of the cells with C29 in the presence of H89 (a SerlThr kinase inhibitor) or 8'-bromo-cyclicAMP revealed that apoptosis was mediated by a cAMP-dependent Ser/Thr kinase. Moreover, C29 increased [cAMP]i over 5-fold. Together, these data suggest that the C29 antiserum against tomoregulin-1 induces apoptosis of hematopoietic cells.
Department of Molecular Animal Physiology, Nijmegen Center for Molecular Life Sciences, University of Nijmegen, The Netherlands. L.C.Penning@vet.uu.nl
Louis C
LC
Penning
Christine J
CJ
Piek
Doug W
DW
Eib
Raymond G
RG
Schipper
Tjadine M
TM
Holling
Gerard J M
GJ
Martens
D000818:Animals; D000906:Antibodies / Q000276:immunology / Q000494:pharmacology*; D017209:Apoptosis / Q000276:immunology*; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology; D002460:Cell Line; D045744:Cell Line, Tumor; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology / Q000494:pharmacology; D019169:Jurkat Cells; D020014:K562 Cells; D007939:Leukemia L1210 / Q000473:pathology / Q000628:therapy; D007962:Leukocytes / Q000166:cytology / Q000276:immunology*; D008565:Membrane Proteins / Q000037:antagonists & inhibitors / Q000276:immunology*; D051379:Mice; D009000:Monocytes / Q000166:cytology / Q000276:immunology; D009363:Neoplasm Proteins / Q000037:antagonists & inhibitors / Q000276:immunology*; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology; D020298:U937 Cells
D000906:Antibodies; D007074:Immunoglobulin G; D008565:Membrane Proteins; D009363:Neoplasm Proteins; C423567:TMEFF2 protein, human; D017346:Protein Serine-Threonine Kinases