It has become clear that an internal death program controls the number and types of immune cells in the body. Diseases can result from inefficient lymphocyte death or from inappropriate or excessive death such as is caused by the human immunodeficiency virus (HIV) during AIDS. In this project we are taking a multifaceted approach to studying molecular mechanisms of this death program in lymphocytes. A major focus of our investigations is a cell surface receptor called CD95/Fas/APO-1 that plays an important role in stimulating the death of immune cells. We are trying to understand how this receptor stimulates the intracellular machinery that causes cellular demise. In particular we have focused on the activation of a protease termed Flice/Mach1 (caspase 8) which can directly carry out the death program. These studies will help us to determine how cells can initiate their own death whose regulation may play a role in various diseases ranging from autoimmune conditions to infectious diseases such as AIDS. Following infection with HIV, a critical effect in the onset of AIDS is believed to be death of T lymphocytes caused by the virus. We have found that this death process is distinct from apoptosis and are making progress in indentifying the viral gene product(s)that are involved in this process. We would then like to explain how the virus product triggers the death of T cells in biochemical terms.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Intramural Research (Z01)
Project #
1Z01AI000718-06
Application #
6431646
Study Section
(LI)
Project Start
Project End
Budget Start
Budget End
Support Year
6
Fiscal Year
2000
Total Cost
Indirect Cost
Name
Niaid Extramural Activities
Department
Type
DUNS #
City
State
Country
United States
Zip Code
Freundt, Eric C; Yu, Li; Park, Elizabeth et al. (2009) Molecular determinants for subcellular localization of the severe acute respiratory syndrome coronavirus open reading frame 3b protein. J Virol 83:6631-40
Yu, Li; Strandberg, Lindsey; Lenardo, Michael J (2008) The selectivity of autophagy and its role in cell death and survival. Autophagy 4:567-73
(2008) Guidelines for the use and interpretation of assays for monitoring autophagy in higher eukaryotes. Autophagy 4:151-75
Liu, Zhihua; Lenardo, Michael J (2007) Reactive oxygen species regulate autophagy through redox-sensitive proteases. Dev Cell 12:484-5
Bolton, Diane L; Lenardo, Michael J (2007) Vpr cytopathicity independent of G2/M cell cycle arrest in human immunodeficiency virus type 1-infected CD4+ T cells. J Virol 81:8878-90
Sakai, Keiko; Dimas, Joseph; Lenardo, Michael J (2006) The Vif and Vpr accessory proteins independently cause HIV-1-induced T cell cytopathicity and cell cycle arrest. Proc Natl Acad Sci U S A 103:3369-74
Yu, Li; Wan, Fengyi; Dutta, Sudeshna et al. (2006) Autophagic programmed cell death by selective catalase degradation. Proc Natl Acad Sci U S A 103:4952-7
Yang, Jin Kuk; Wang, Liwei; Zheng, Lixin et al. (2005) Crystal structure of MC159 reveals molecular mechanism of DISC assembly and FLIP inhibition. Mol Cell 20:939-49
Speirs, Christina; van Nimwegen, Erik; Bolton, Diane et al. (2005) Analysis of human immunodeficiency virus cytopathicity by using a new method for quantitating viral dynamics in cell culture. J Virol 79:4025-32
Clancy, Lauren; Mruk, Karen; Archer, Kristina et al. (2005) Preligand assembly domain-mediated ligand-independent association between TRAIL receptor 4 (TR4) and TR2 regulates TRAIL-induced apoptosis. Proc Natl Acad Sci U S A 102:18099-104

Showing the most recent 10 out of 38 publications