Characterization of anti-human interleukin-18 (IL-18)/interferon-gamma-inducing factor (IGIF) monoclonal antibodies and their application in the measurement of human IL-18 by ELISA.
Interleukin-18 (IL-18)/interferon-gamma-inducing factor (IGIF) is a novel cytokine, which is a potent inducer of IFN-gamma production and plays an important role in Th1 responses. In order to develop a specific ELISA for the measurement of human IL-18, we established 13 anti-human IL-18 monoclonal antibodies and characterized them. 7 murine anti-human IL-18 mAbs and 6 rat anti-human IL-18 mAbs were obtained by fusion of splenocytes from mice or rats immunized with human IL-18, with SP2/0 myeloma cells. These antibodies were classified into 4 groups according to competitive binding ELISAs to the human IL-18 molecule. 1 murine mAb and all 6 rat mAbs neutralized IFN-gamma production induced by IL-18. A specific human IL-18 ELISA was developed using two neutralizing mAbs (#125-2H and #159-12B). This ELISA detects human IL-18 with a minimum detection limit of 10 pg/ml, but does not react with heat-denatured human IL-18. The ELISA does not show any cross-reactivity with other cytokines. Using this assay, human IL-18 was measurable in the plasma of leukemia patients. This ELISA would become a powerful tool for investigating the relationship between IL-18 and various diseases or analyzing the control mechanisms of IL-18 production from IL-18 producing cells.
Taniguchi
M
M
Fujisaki Institute, Hayashibara Biochemical Laboratories Inc., Okayama, Japan. fujih@po.harenet.or.jp
Nagaoka
K
K
Kunikata
T
T
Kayano
T
T
Yamauchi
H
H
Nakamura
S
S
Ikeda
M
M
Orita
K
K
Kurimoto
M
M
D000328:Adult; D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry*; D002460:Cell Line; D003429:Cross Reactions; D016207:Cytokines / Q000097:blood* / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis*; D020382:Interleukin-18; D007938:Leukemia / Q000097:blood / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D011817:Rabbits; D051381:Rats; D017207:Rats, Sprague-Dawley
D000911:Antibodies, Monoclonal; D016207:Cytokines; D020382:Interleukin-18; D007371:Interferon-gamma