TLR9 and the recognition of self and non-self nucleic acids

Student Author(s)

Cherilyn M. Sirois

Academic Program

Interdisciplinary Graduate Program

UMMS Affiliation

Department of Medicine, Division of Infectious Diseases and Immunology

Publication Date


Document Type



Immunology and Infectious Disease | Life Sciences | Medicine and Health Sciences


Toll-like receptors (TLRs) are involved in the innate recognition of foreign material and their activation leads to both innate and adaptive immune responses directed against invading pathogens. TLR9 is intracellularly expressed in the endo-lysosomal compartments of specialized immune cells. TLR9 is activated in response to DNA, in particular DNA containing unmethylated CpG motifs that are more prevalent in microbial than mammalian DNA. By detecting foreign DNA signatures TLR9 can sense the presence of certain viruses or bacteria inside the cell and mount an immune response. However, under certain conditions, TLR9 can also recognize self-DNA and this may promote immune pathologies with uncontrolled chronic inflammation. The autoimmune disease systemic lupus erythematosis (SLE) is characterized by the presence of immune stimulatory complexes containing autoantibodies against endogenous DNA and DNA- and RNA-associated proteins. Recent evidence indicates that the autoimmune response to these complexes involves TLR9 and the related single-stranded RNA-responsive TLRs 7 and 8, and therefore some breakdown in the normal ability of these TLRs to distinguish self and foreign DNA. Evidence suggests that immune cells use several mechanisms to discriminate between stimulatory and nonstimulatory DNA; however, it appears that TLR9 itself binds rather indiscriminately to a broad range of DNAs. We therefore propose that there is an additional recognition step by which TLR9 senses differences in the structures of bound DNA.

DOI of Published Version



LAMPHIER, M. S., SIROIS, C. M., VERMA, A., GOLENBOCK, D. T. and LATZ, E. (2006), TLR9 and the Recognition of Self and Non-Self Nucleic Acids. Annals of the New York Academy of Sciences, 1082: 31–43. doi: 10.1196/annals.1348.005

Journal/Book/Conference Title

Annals of the New York Academy of Sciences

Related Resources

Link to article in PubMed

PubMed ID