title: Therapeutic efficacy of experimental rheumatoid arthritis with low-dose methotrexate by increasing partially CD4+CD25+ Treg cells and inducing Th1 to Th2 shift in both cells and cytokines.
abstract: Low-dose methotrexate (MTX), a traditional folate antagonist and disease-modifying antirheumatic drug administered weekly either alone or as combination therapy, is widely accepted as the gold standard in rheumatoid arthritis (RA) treatment. Although its mechanism of action in RA is still poorly understood, MTX potentially acts via antiproliferative, anti-inflammatory, and/or immunosuppressive means. The therapeutic mechanisms and efficacy of low-dose MTX and the oral tolerance protein natural chicken type II collagen (nCCII) were compared in vitro and in vivo using an established collagen-induced arthritis (CIA) rat model. We used clinical visual scoring, radiographic X-ray analysis, histopathological examination, and sera anti-CII IgG measurements to determine the severity of disease with and without treatment. Low-dose MTX had significant clinical therapeutic efficacy against established CIA. Similar to nCCII, MTX mediated CIA by specific immunotolerant effects and not by nonspecific immunosuppression. The mechanism underlying the therapeutic efficacy could be at least partially attributed to the increased production of CD4+CD25+ Treg cells. These cells specifically downmodulated the T lymphocyte proliferative response to CCII but not PHA, induced a Th1-to-Th2 shift, downregulated Th1 cytokines, and upregulated both Th2 and Th3 cytokines. To the best of our knowledge, this is the first demonstration that low-dose MTX probably serves as a potent inducer of specific immunotolerance but not of nonspecific immunosuppression in the treatment of RA.
authors.affiliation: Department of Immunology and National Center for Biomedicine Analysis, Beijing 307 Hospital Affiliated to Academy of Medical Sciences, No. 8, Dongda Ave, Fengtai District, Beijing 100071, PR China.
authors.forename: Song
authors.initials: S
authors.lastname: Xinqiang
authors.forename: Liang
authors.initials: L
authors.lastname: Fei
authors.forename: Liu
authors.initials: L
authors.lastname: Nan
authors.forename: Luo
authors.initials: L
authors.lastname: Yuan
authors.forename: Yuan
authors.initials: Y
authors.lastname: Fang
authors.forename: Xue
authors.initials: X
authors.lastname: Hong
authors.forename: Tan
authors.initials: T
authors.lastname: Lixin
authors.forename: Long
authors.initials: L
authors.lastname: Juan
authors.forename: Zhao
authors.initials: Z
authors.lastname: Xiao
authors.forename: Sun
authors.initials: S
authors.lastname: Yuying
authors.forename: Xi
authors.initials: X
authors.lastname: Yongzhi
mesh_terms: D000818:Animals; D018501:Antirheumatic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D001169:Arthritis, Experimental / Q000188:drug therapy* / Q000276:immunology / Q000473:pathology; D001172:Arthritis, Rheumatoid / Q000188:drug therapy* / Q000276:immunology; D018791:CD4 Lymphocyte Count; D024043:Collagen Type II / Q000276:immunology; D016207:Cytokines / Q000378:metabolism*; D005260:Female; D007108:Immune Tolerance; D008213:Lymphocyte Activation; D008727:Methotrexate / Q000008:administration & dosage / Q000627:therapeutic use*; D051381:Rats; D017208:Rats, Wistar; D006377:T-Lymphocytes, Helper-Inducer / Q000187:drug effects / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*; D018417:Th1 Cells / Q000187:drug effects / Q000276:immunology; D018418:Th2 Cells / Q000187:drug effects / Q000276:immunology
chemical_list: D018501:Antirheumatic Agents; D024043:Collagen Type II; D016207:Cytokines; D008727:Methotrexate