title: Interleukin-15 receptor-directed immunotoxins atteunuate disease severity in rat adjuvant arthritis.
abstract: We previously constructed two Pseudomonas exotoxin (PE)-based immunotoxins, IL15-PEDelta293 (IT1) and IL15M-PEDelta293 (IT2), for eliminating interleukin-15 receptor (IL-15R)-overexpressing cells. These two immunotoxins were generated by fusing either wild-type human IL-15 or an antagonist mutant IL-15 (IL-15M) to a modified form of PE. In this study the anti-arthritic effect of IT1 and IT2 was investigated using the rat model of adjuvant arthritis (AA). We found that both IT1 and IT2 could specifically target IL-15R-positive cells and induce apoptosis. After AA induction, treatment with either IT1 or IT2 resulted in profound improvement of the disease, with reductions in levels of synovial mononuclear leukocytes and certain inflammatory factors. Clinical and histological comparisons, together with the analyses of mRNA expression and the signal transducer and activator of transcription-3 (STAT-3) phosphorylation, revealed that the two immunotoxins decreased joint inflammation in AA rats to a similar extent. These data suggest that eliminating IL-15R-bearing cells via immunotoxins may be a promising approach for RA treatment. In addition, wild-type IL-15-based immunotoxins can be as effective as antagonist mutant IL-15-based immunotoxins in preventing joint inflammation associated with rheumatoid arthritis.
authors.affiliation: Key Laboratory of Ministry of Education for Developmental Genes and Human Diseases, School of Basic Medical Sciences, Southeast University, 87 Dingjiaqiao Road, Nanjing, Jiangsu 210009, China.
authors.forename: Deling
authors.initials: D
authors.lastname: Wang
authors.forename: Xianglei
authors.initials: X
authors.lastname: Deng
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Leng
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Mao
mesh_terms: D000818:Animals; D001169:Arthritis, Experimental / Q000235:genetics / Q000276:immunology* / Q000378:metabolism / Q000473:pathology*; D045744:Cell Line, Tumor; D005786:Gene Expression Regulation; D006801:Humans; D000922:Immunotoxins / Q000276:immunology*; D008297:Male; D010766:Phosphorylation; D011549:Pseudomonas / Q000276:immunology*; D051381:Rats; D017208:Rats, Wistar; D053647:Receptors, Interleukin-15 / Q000276:immunology*; D050796:STAT3 Transcription Factor / Q000378:metabolism
chemical_list: D000922:Immunotoxins; D053647:Receptors, Interleukin-15; D050796:STAT3 Transcription Factor; C494088:Stat3 protein, rat