Mice with mutations of TNFRSF1A may reveal insights into pathogenesis of TRAPS, a dominantly inherited autoinflammatory disease

• Published in: Journal of allergy and clinical immunology 2004-02, Vol.113 (2), p.S205-S205
• Main Authors: Komarow, H.D., Chae, J.J., Raben, N., Wood, G., Kastner, D.L.
• Format: Article
• Language: English
• ISSN: 0091-6749; 1097-6825
• DOI: 10.1016/j.jaci.2004.01.184

Heterozygous mutations in the extracellular domain of the 55-kDa tumor necrosis factor (TNF) receptor (TNFRSF1A), a key regulator of inflammation, define a periodic fever syndrome, TRAPS (TNF receptor-associated-periodic syndrome) that is characterized by attacks of fever, sterile peritonitis, arthralgia, myalgia, skin rash and/or conjunctivitis; some patients also develop amyloidosis. The autoinflammatory phenotype has been associated with impaired downregulation of membrane TNFRSF1A and diminished shedding of potentially antagonistic soluble receptor. To facilitate additional study of the effects of these mutations on TNFRSF1A, we generated a mouse model for TRAPS. Two (of the 33 reported) mutations generated by site-directed mutagenesis were utilized for the generation of knock-in mice: Cys33Tyr (C33Y) and Thr50Met (T50M). Heterozygous and homozygous animals for T50M and C33Y have been generated. Current investigations defining their phenotype include observation, mouse core body temperature studies, gene expression studies, Tnfr-1 receptor shedding assays, inflammatory cytokine profiles (IL-1, TNF alpha, IL-6) and histologic studies. Mice homozygous for T50M show resistance to lethal doses of lipopolysaccaride. Following low dose injection of endotoxin these mice show resistance to hyperthermia, decreased Tnfsfr1a shedding in serum, and decreased production of proinflammatory cytokines: TNFa and IL-6. Heterozygous littermates showed an intermediate phenotype for in vitro assays. Preliminary studies also indicated alterations in B and T cell ratios. These mouse models confirm previous reports that mutations in TNFSFR1A cause diminished receptor cleavage and additionally suggest TNFSF1A signaling defects, which may help to further elucidate the autoinflammatory phenotype in TRAPS.