BACKGROUND Protease activated receptor 2 (PAR2) is a G-protein coupled receptor which has a role in inflammation. Previous work in collagen induced arthritis (CIA) has shown that PAR2 gene disruption results in significant reduction of pro-inflammatory mediators however the impact on T regulatory (Treg) cells was not investigated. AIM To investigate the role of PAR2 in Treg development and effector function using an in vitro approach.METHODSNaive CD4+ T cells were isolated from spleens from wild type (WT) and PAR2 gene disrupted or knock out (KO) mice and subsequently polarised in vitro towards a Treg phenotype in the presence of CD3/CD28 and TGF . After 5 days, the number of CD4+/CD25+/Foxp3+ Treg was evaluated along with expression of CTLA-4 and LAG3. Interleukin 10 (IL-10) levels were determined in culture supernatants. Data is presented as mean values SEM and is representative of 3-5 independent experiments.RESULTSNaive CD4+ cells cultured in vitro under Treg polarising conditions for 5 days were found to be CD4+/CD25+ (88%5 vs 90%2; WTvsKO), with no significant difference in Foxp3 expression between groups (26% 9 vs 35% 6; WTvsKO). LAG3 was observed on both WT and KO CD4+/CD25+ cells, with no difference between the groups. PAR2KO CD4+/CD25+ cells were found to have increased expression of CTLA-4 in 3 out of 4 independent experiments however this failed to reach statistical significance (39%20 vs 8%6; KOvsWT). Interestingly PAR2KO Treg supernatants were found to contain significantly more IL-10 than those from WT Treg (1609 pg/ml 24 vs 805 pg/ml 23, respectively, p<0.001).CONCLUSIONPAR2 does not appear to have a role in Treg development in vitro, but may impact effector function by influencing IL-10 secretion and CTLA-4 expression. This data highlights a novel role for PAR2 in Treg biology.
|Publication status||Published - 8 Dec 2016|
|Event||BSI/NVVI Annual Congress 2016 - Arena Conference Centre, Liverpool, United Kingdom|
Duration: 6 Dec 2016 → 9 Dec 2016
|Conference||BSI/NVVI Annual Congress 2016|
|Period||6/12/16 → 9/12/16|