Enhanced autoimmunity, arthritis, and encephalomyelitis in mice with a reduced oxidative burst due to a mutation in the Ncf1 gene.

The Ncf1 gene was recently identified as a strong regulator of severe arthritis in rat. This finding was surprising, because the disease-promoting allele mediated a lower level of reactive oxygen species in NADPH oxidase-expressing cells. We have now investigated a splice mutation of the Ncf1 gene in B10.

Positional identification of Ncf1 as a gene that regulates arthritis severity in rats.

The identification of genes underlying quantitative-trait loci (QTL) for complex diseases, such as rheumatoid arthritis, is a challenging and difficult task for the human genome project. Through positional cloning of the Pia4 QTL in rats, we found that a naturally occurring polymorphism of Ncf1 (encoding neutrophil cytosolic factor 1, a component of the NADPH oxidase complex) regulates arthritis severity. The disease-related allele of Ncf1 has reduced oxidative burst response and promotes activation of arthritogenic T cells.