1). T cell proliferation was monitored by 3H-thymidine incorporation from day 2 to 7. Peak proliferation on day 5 was compared. 2.7. In Vivo DC Maturation C57BL/6 mice were injected with LPS (2μg) or CpG intradermally into each footpad, with or without IFN-gamma (2ng). After 18h, popliteal lymph node cells were collected. All mice

were treated and handled as approved by the AMREP animal ethics committee, Melbourne Australia and in accordance to the ethics guidelines by NHMRC Australia. The maturation state of live CD11c+ DCs was determined by labelling with FITC-conjugated anti-CD80 and anti-CD86 and analyzed by flow cytometry. 2.8. Statistical Analysis All data are shown as the mean ± standard Inhibitors,research,lifescience,medical error of the mean (SEM). The data generated in this study were analyzed by student’s t-test. Significance of difference Inhibitors,research,lifescience,medical was determined by the P value (≤0.05). 3. Results 3.1. IFN-Gamma Enhances DC Maturation with or without TLR Ligands The ability of IFN-gamma

to promote DC maturation in vitro was assessed using day 5 bone marrow-derived DC in the presence or absence of TLR ligands, LPS (TLR4), and CpG (TLR9), by measuring cell surface expression of CD40, CD80, CD86, and MHC class II (Figure 1). IFN-gamma alone had a moderate effect on the upregulation of the activation markers, AR-A014418 concentration compared to untreated cells, most notably causing Inhibitors,research,lifescience,medical an enhancement in the levels of CD86 and MHC II expression. Likewise, CpG alone induced low levels Inhibitors,research,lifescience,medical of expression of the four surface markers compared to untreated cells; however, this was augmented in the presence of IFN-gamma, most notably, C40 and CD86. LPS strongly induced DC maturation as measured by the expression of the activation Inhibitors,research,lifescience,medical markers, and in the presence of IFN-gamma, only CD40 expression was further upregulated, albeit weak. Figure 1 IFN-gamma enhances DC maturation with or without TLR ligands in vitro. C57BL/6 bone marrow cells

were cultured with GM-CSF to generate bone marrow derived DCs. At days 4-5, cells were preconditioned with IFN-gamma for 2h (solid line) or no IFN-gamma … The ability of IFN-gamma to promote DC maturation in vivo was similarly assessed, following hock injection of mice with check IFN-gamma in the presence or absence of TLR ligands (Figure 2). CD11c+ DCs from the popliteal lymph nodes showed increased CD80 and CD86 expression following IFN-gamma injection, compared to PBS-injected mice. Again, LPS alone strongly induced the expression of both activation markers which was not further augmented in the presence of IFN-gamma. CpG alone had minimal effect on CD86 expression, but increased CD80 expression; however, the inclusion of IFN-gamma further upregulated the expression of both markers, indicating enhancement of bone marrow-derived DC maturation. Figure 2 IFN-gamma enhances DC maturation with or without TLR ligands in vivo.