Development of a mouse-feline chimeric antibody against feline tumor necrosis factor-alpha

DOKI, Tomoyoshi; TAKANO, Tomomi; HOHDATSU, Tsutomu

Anti-TNF-alpha agents are expected to improve the symptoms of FIP caused by viral infection. We previously described the preparation of a feline TNF-alpha (fTNF-alpha)neutralizing mouse monoclonal antibody (anti-fTNF-alpha mAb, mAb [2] [3] [4] . This mAb 2-4 exhibited high neutralizing activity against recombinant and natural TNF-alpha, and was confirmed to inhibit the following fTNF-alpha-induced conditions in vitro: i) an increase in the survival rate of neutrophils from cats with FIP, ii) APN mRNA expression in macrophages and iii) apoptosis of a feline T-lymphocyte cell line [4] . These findings strongly suggested that mAb 2-4 is applicable as a therapeutic drug against FIP. We are also investigating that mouse mAb 2-4 administration to SPF cats experimentally infected with FIPV alleviated the clinical condition of cat with FIP [3] . However, because this is a mouse-derived antibody and is a xenogeneic protein for cats, induction of feline anti-mouse antibodies may reduce the reactivity of mouse mAb 2-4 against fTNF-alpha.