Genomes and Genes
Mutagenic analysis of LPS responses
Principal Investigator: BRUCE A BEUTLER
Affiliation: The Scripps Research Institute
Abstract: The LPS signaling pathway has been analyzed using a combination of biochemical and genetic methods. Yet, to the present time, not all of the proteins that participate in LPS detection have been identified. In order to find more of them, a forward genetic strategy has been used. Germline mutations are induced in mice using N-ethyl-N-nitrosourea (ENU), and the mutants are systematically screened for their ability to respond to primary challenge with LPS, as well as their ability to develop LPS tolerance. Among the first 1365 F1 and 1686 F3 mice analyzed in this manner, three transmissible mutations have been detected. An autosomal recessive mutation, Lps2, abolishes the primary LPS response but does not reside in any of the genes that are presently known to be essential for LPS sensing. Two other mutations, one dominant and one recessive, block the development of LPS tolerance. Lps2 has been excluded from more than 99% of the genome by genetic mapping. In the present proposal, we outline plans for high-resolution mapping and cloning these mutations. Moreover, since germline mutagenesis is clearly an effective means of finding the essential cellular components of LPS sensing and feedback inhibition pathways, we will extend our effort to approach saturation, cloning all mutations that show a strong phenotypic effect. The existing mutations, and all future mutations that are acquired through this forward genetic approach, will be subjected to advanced phenotypic analysis to determine the level at which they affect LPS signaling. In the case of mutations that abolish LPS tolerance, we will attempt to determine the net impact on host resistance to infection.
Funding Period: 2003-09-08 - 2007-08-31
more information: NIH RePORT
- Genetic analysis of innate immunity: identification and function of the TIR adapter proteinsBruce Beutler
Scripps Research Institute, Department of Immunology, IMM 31, 10550 N Torrey Pines Road, La Jolla, California 92037, USA
Adv Exp Med Biol 560:29-39. 2005..Other key innate immunity genes have also been disclosed by germline mutagenesis, and are discussed in the present review...
- TLR signaling pathways: opportunities for activation and blockade in pursuit of therapyK Hoebe
Department of Immunology, IMM 31, The Scripps Research Institute, 10550 N Torrey Pines Road, La Jolla, CA 92037 USA
Curr Pharm Des 12:4123-34. 2006..Classical and reverse genetic analyses offer insight into the possibilities that exist, and point to specific checkpoints within signaling pathways at which modulation might normally be imposed...
- Inflammation and autoimmunity caused by a SHP1 mutation depend on IL-1, MyD88, and a microbial triggerBen A Croker
Department of Genetics, The Scripps Research Institute, 10550 N Torrey Pines Road, La Jolla, CA 92037, USA
Proc Natl Acad Sci U S A 105:15028-33. 2008..The SHP1-deficient phenotype is driven by microbes, which activate TLR signaling pathways to elicit IL-1 production. IL-1 signaling via MyD88 elicits inflammatory disease...
- Mice with mutations of Dock7 have generalized hypopigmentation and white-spotting but show normal neurological functionAmanda L Blasius
Departments of Genetics and Molecular and Experimental Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
Proc Natl Acad Sci U S A 106:2706-11. 2009..However, DOCK7 has non-redundant role(s) related to the distribution and function of dermal and follicular melanocytes...
- Endosomal TLR signaling is required for anti-nucleic acid and rheumatoid factor autoantibodies in lupusDwight H Kono
Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037, USA
Proc Natl Acad Sci U S A 106:12061-6. 2009..Importantly, this helps provide an explanation for the high frequency of anti-nucleic acid Abs in lupus-like systemic autoimmunity...