CTLA4-Ig interacts with cultured synovial macrophages from rheumatoid arthritis patients and downregulates cytokine production
IntroductionCo-stimulatory signal B7(CD80/CD86):CD28 is needed in order to activate T cells in immune response. Cytotoxic T lymphocyte-associated antigen-4-immunoglobulin (CTLA4-Ig) binding to the B7 molecules on antigen-presenting cells downregulates this activation and represents a recent biological treatment in rheumatoid arthritis (RA).
Objectives of the study were to investigate the presence of the B7.2 (CD86) molecule and its masking by CTLA4-Ig on cultures of both RA synovial macrophages (RA SM), and of macrophages differentiated from THP-1 cells (M). In addition, the anti-inflammatory effects of CTLA4-Ig on co-cultures of RA SM and M with activated T cells were tested.
Methods: All macrophages were co-cultured for 24 hours with activated T cells, without or with CTLA4-Ig (10, 100, 500 mg/ml for 1 hour, 3 hours and overnight, respectively).
Immunofluorescence (IF) staining for B7.2, and an analysis of inflammatory cytokine expression (interleukin(IL)-6, tumor necrosis factor(TNF)alfa, IL-1beta, transforming growth factor(TGF)beta) by immunocytochemistry (ICC), western blot (WB) and reverse transcriptase-polymerase chain reaction (RT-PCR) were performed.
Results: Macrophages showed intense B7.2 expression. CTLA4-Ig/B7.2 masking was evident for all macrophages, even after only 1 hour of cell culture (range from 10 to 100 mg/ml).
ICC of co-cultures showed a dose-dependent decrease in inflammatory cytokines (P<0.001 for IL-6, TNFalpha, IL-1beta and TGFbeta). Data were confirmed by WB and RT-PCR analysis.
Conclusions: Optimal concentrations of CTLA4-Ig for the CTLA4-Ig/B7.2 masking on activated macrophages were identified and were found to induce significant downregulation in the cell production of IL-6, TNFalpha, IL1-beta and TGFbeta.
In conclusion, macrophages would appear to be a sensitive target for CTLA4-Ig treatment in RA.
Author: Maurizio CutoloStefano SoldanoPaola MontagnaAlberto SulliBruno SerioloBarbara VillaggioPierfranco TrioloPaolo ClericoLamberto FelliRenata Brizzolara
Credits/Source: Arthritis Research &Therapy 2009, 11:R176
Published on: 2009-11-23
Copyright by the authors listed above - made available via BioMedCentral (Open Access). Please
make sure to read our disclaimer prior to contacting 7thSpace Interactive. To contact our editors, visit our online helpdesk. If you wish submit your own press release, click here.
Social Bookmarking
RETWEET This! | Digg this! | Post to del.icio.us | Post to Furl | Add to Netscape | Add to Yahoo! | Rojo
|
|
