AB0057 IN VITRO EFFECT OF CTLA4-IGG ON M1-M2 SHIFT OF MACROPHAGES FROM RHEUMATOID ARTHRITIS PATIENTS

Background: Among the cells involved in inflammatory process of rheumatoid arthritis (RA) [1], macrophages play a key role through their capacity to polarize into “classically” or “alternatively” activated phenotypes (M1 M2) and making important players for cascade anti-inflammatory reaction, respectively [2]. CTLA4-Ig fusion protein (abatacept) has been shown contribute macrophage shift from M1 M2 [3]. Objectives: We aimed investigate effects abatacept induce polarization pro-inflammatory phenotype cultured human obtained RA patients’ healthy subjects’(HS) circulating monocytes. Methods: Cultured monocytes were isolated peripheral blood mononuclear (PBMCs) three early patients ten HS, after signing informed consent Ethics Committee approval. Cells treated with phorbol myristate acetate (PMA) [5ng/ml] 24 hours (hrs) differentiation monocyte-derived (MDMs). Therefore, HS MDMs stimulated lipopolysaccharides [LPS, 1mg/mL] 4hrs [4] order then not at concentrations 100mg/mL 500mg/mL 3, 12, 48hrs. MDMs, directly as previous described. without any stimuli treatment used respective control. The transition was evaluated gene expression synthesis markers, namely scavenger receptors (CD163 CD204), mannose receptor-1 (CD206) by quantitative real-time polymerase chain reaction (PCR) Western blotting. statistical analysis evaluation carried out GraphPad Prism 8 software using Wilcoxon non-parametric t-test. Any p-value lower than 0.05 considered statistically significant. Results indicated median±standard deviation (SD). Results: In (three cases), upregulated all investigated specifically 12hrs concentration 100mg/mL. these cells, only CD204 more evidence 24hrs concentration. (ten significantly that CD206 [at 3hrs concentration, p= 0.0312] CD163 0.0312]. Moreover, 48hrs 0.0195] 0.0156; both 0.0234]. Conclusion: Preliminary data seem indicate can promote vitro phenotype, upregulating specific markers (CD163, CD204, CD206) M1-MDMs induced HS. References: [1]McInnes IB, et al. N Engl J Med 2011;365:2205–19. [2]Fujii M, Biochem Biophys Res Commun. 2013;438(1):103-9. [3]Cutolo Arthritis Ther. 2009;11:R176. [4]Pelegrin P., Surprenant, A. EMBO J. 2009 Jul 22; 28(14): 2114–2127. Disclosure Interests: Samuele Tardito: None declared, Stefano Soldano: Emanuele Gotelli: Paola Montagna: Sabrina Paolino: Vanessa Smith: Maurizio Cutolo Grant/research support from: I received grant/research Bristol-Myers Squibb, Boehringer, Celgene.