The discovery of nitric oxide as a regulator of blood pressure, which was awarded the Nobel prize in 1995, launched intense investigation into its function in human health. Recognizing the diversity, complexity and conservation of nitric oxide actions, studies in model organisms appear relevant and needed. In our studies of Drosophila, nitric oxide induced behavioral and physiological changes consistent with a conserved role in adaptation to low oxygen (hypoxia). Seeking other parallels to its function in mammals, we found that nitric oxide activates innate immune responses in Drosophila. We developed robust assays in which tagged transgenes report immune induction in larvae or cultured cells (S2 cells) in response to nitric oxide, or to bacteria, or to hypoxia. The responses of S2 cells can be blocked by inactivation of specific genes by RNA interference (RNAi). To exploit this powerful avenue for genetic dissection, we constructed a library of 7,200 RNAs representing the conserved genes of Drosophila. We propose high-throughput RNAi screens for genes contributing to immune induction. In preliminary work, we identified the genes involved in the response to bacterial components and will do the same for genes involved in the responses to nitric oxide and hypoxia. We will further exploit our assays to define the sequence of gene action, thereby delineating distinctions and commonalities in the pathways transducing these signals. Using in vivo genetics and tests in culture, we will place the signaling pathways in their biological context. Localization of function will position gene action in a cascade that conveys immune responses from the site of infection to distant tissues. These studies will provide new models for the action of signals central to human physiology and health. ? ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI060102-07
Application #
7029613
Study Section
Development - 1 Study Section (DEV)
Program Officer
Winter, David B
Project Start
2000-03-01
Project End
2008-03-31
Budget Start
2006-04-01
Budget End
2007-03-31
Support Year
7
Fiscal Year
2006
Total Cost
$332,865
Indirect Cost
Name
University of California San Francisco
Department
Biochemistry
Type
Schools of Medicine
DUNS #
094878337
City
San Francisco
State
CA
Country
United States
Zip Code
94143
DeLuca, Steven Z; O'Farrell, Patrick H (2012) Barriers to male transmission of mitochondrial DNA in sperm development. Dev Cell 22:660-8
Dijkers, Pascale F; O'Farrell, Patrick H (2009) Dissection of a hypoxia-induced, nitric oxide-mediated signaling cascade. Mol Biol Cell 20:4083-90
Stroschein-Stevenson, Shannon L; Foley, Edan; O'Farrell, Patrick H et al. (2009) Phagocytosis of Candida albicans by RNAi-treated Drosophila S2 cells. Methods Mol Biol 470:347-58
Lee, Soo-Jung; Feldman, Renny; O'Farrell, Patrick H (2008) An RNA interference screen identifies a novel regulator of target of rapamycin that mediates hypoxia suppression of translation in Drosophila S2 cells. Mol Biol Cell 19:4051-61
Xu, Hong; DeLuca, Steven Z; O'Farrell, Patrick H (2008) Manipulating the metazoan mitochondrial genome with targeted restriction enzymes. Science 321:575-7
Dijkers, Pascale F; O'Farrell, Patrick H (2007) Drosophila calcineurin promotes induction of innate immune responses. Curr Biol 17:2087-93
Stroschein-Stevenson, Shannon L; Foley, Edan; O'Farrell, Patrick H et al. (2006) Identification of Drosophila gene products required for phagocytosis of Candida albicans. PLoS Biol 4:e4