Interactions of human T cell immunoglobin mucins with apoptotic cells

Abstract

T cell immunoglobulin mucin (TIM) family plays a key role in regulating immune responses. In this study, the interactions of human TIM family with apoptotic cells were evaluated in order to provide a foundation for further study on the roles of human TIM genes in apoptosis. Nine kinds of pEGFP-N1 eukaryotic expression vectors containing different lengths of the three members of human TIM genes for the expression of TIM-EGFP and the vectors for the expression of TIM-Fc fusion proteins were constructed. It was found that human TIM proteins could recognize and bind to apoptotic cells directly, but not to viable cells. The interactions of sTIM-1-EGFP, sTIM-3-EGFP and sTIM-4-EGFP with apoptotic cells were blocked by TIM-1-Ig, TIM-3-Ig and TIM-4-Ig fusion proteins respectively. In addition, human TIM proteins mediated the recognition of apoptotic cells and bound to apoptotic cells directly via the IgV domains. In conclusion, the TIM family may play a key role in the regulation of apoptosis. Our data also suggest that human TIM proteins probably serve as novel proteins for the detection of the early cellular apoptosis.

Keywords

apoptosis / T cell immunoglobulin mucin gene / fusion protein / receptor / immune response / pervanadate

References

[1] FadeelB., OrreniusS.. Apoptosis: a basic biological phenomenon with wide-ranging implications in human disease. J Intern Med, 2005, 258(6): 479-517

[2] HeemelsM.T.. Apoptosis. Nature, 2000, 407(6805): 769

[3] MeierP., FinchA., EvanG.. Apoptosis in development. Nature, 2000, 407(6805): 796-801

[4] ElliottM.R., RavichandranK.S.. Clearance of apoptotic cells: implications in health and disease. J Cell Biol, 2010, 189(7): 1059-1070

[5] FadokV.A., VoelkerD.R., CampbellP.A., et al.. Exposure of phosphatidylserine on the surface of apoptotic lymphocytes triggers specific recognition and removal by macrophages. J Immunol, 1992, 148(7): 2207-2216

[6] MeyersJ.H., SabatosC.A., ChakravartiS., et al.. The TIM gene family regulates autoimmune and allergic diseases. Trends Mol Med, 2005, 11(8): 362-369

[7] Rodriguez-ManzanetR., DeKruyffR., KuchrooV.K., et al.. The costimulatory role of TIM molecules. Immunol Rev, 2009, 229(1): 259-270

[8] SantiagoC., BallesterosA., Martinez-MunozL., et al.. Structures of T cell immunoglobulin mucin protein 4 show a metal-ion-dependent ligand binding site where phosphatidylserine binds. Immunity, 2007, 27(6): 941-951

[9] SantiagoC., BallesterosA., TamiC., et al.. Structures of T cell immunoglobulin mucin receptors 1 and 2 reveal mechanisms for regulation of immune responses by the TIM receptor family. Immunity, 2007, 26(3): 299-310

[10] CaoE., ZangX., RamagopalU.A., et al.. T cell immunoglobulin mucin-3 crystal structure reveals a galectin-9-independent ligand-binding surface. Immunity, 2007, 26(3): 311-321

[11] NakayamaM., AkibaH., TakedaK., et al.. Tim-3 mediates phagocytosis of apoptotic cells and cross-presentation. Blood, 2009, 113(16): 3821-3830

[12] MiyanishiM., TadaK., KoikeM., et al.. Identification of Tim4 as a phosphatidylserine receptor. Nature, 2007, 450(7168): 435-439

[13] KobayashiN., KarisolaP., Pena-CruzV., et al.. TIM-1 and TIM-4 glycoproteins bind phosphatidylserine and mediate uptake of apoptotic cells. Immunity, 2007, 27(6): 927-940

[14] GordonJ.A.. Use of vanadate as protein-phosphotyrosine phosphatase inhibitor. Methods Enzymol, 1991, 201: 477-482

[15] KuchrooV.K., UmetsuD.T., DeKruyffR.H., et al.. The TIM gene family: emerging roles in immunity and disease. Nat Rev Immunol, 2003, 3(6): 454-462

[16] ZhouZ.. New phosphatidylserine receptors: clearance of apoptotic cells and more. Dev Cell, 2007, 13(6): 759-760

[17] IchimuraT., AsseldonkE.J., HumphreysB.D., et al.. Kidney injury molecule-1 is a phosphatidylserine receptor that confers a phagocytic phenotype on epithelial cells. J Clin Invest, 2008, 118(5): 1657-1668

[18] SabatosC.A., ChakravartiS., ChaE., et al.. Interaction of Tim-3 and Tim-3 ligand regulates T helper type 1 responses and induction of peripheral tolerance. Nat Immunol, 2003, 4(11): 1102-1110

[19] GengH., ZhangG.M., LiD., et al.. Soluble form of T cell Ig mucin 3 is an inhibitory molecule in T cell-mediated immune response. J Immunol, 2006, 176(3): 1411-1420

[20] BaillyV., ZhangZ., MeierW., et al.. Shedding of kidney injury molecule-1, a putative adhesion protein involved in renal regeneration. J Biol Chem, 2002, 277(42): 39739-39748

[21] VanE.M., NielandL.J., RamaekersF.C., et al.. Annexin V-affinity assay: a review on an apoptosis detection system based on phosphatidylserine exposure. Cytometry, 1998, 31(1): 1-9