LPS treatment impairs nicotine-augmenting DCs-mediated Ag-specific T cell priming.

<p>DCs derived from murine bone marrow with GM-CSF and IL-4 were conferred with nicotine (10⁻⁷ M) or LPS (10 ng/ml) for 12 h. (A and B) the effect of nicotine or LPS on surface molecules expression was firstly determined via flow cytometry. After pulsed with OVA CD8⁺ T cell peptide SIINFEKL (2 µg/ml), the DCs were conferred flow cytometry assay to monitor SIINFEKL-H2Kb complex formation (C), co-incubation with splenocytes at a ratio of 1∶10 <i>in vitro</i> for 3 d (D) or intraperitoneal adoptive transfer to C57BL/6 donor (E). Then, the effect of nicotine or LPS on DCs-dependent T cell proliferation and Ag-specific CTL priming <i>in vivo</i> was determined via BrdU cell proliferation assay (D) and IFN-gamma Elispot assay (E), respectively. For IFN-gamma Elispot assay, the assay was performed 5 d after intraperitoneal transfer of 5×10⁵ DCs in the presence of SIINFEKL peptide (2 µg/ml) (n = 3). For flow cytometry (A-C), numbers in histogram indicated mean fluorescence intensity (MFI) of test samples except for CD11c flow cytometry assay indicated the positive percentages of analyzed samples. **p<0.01, ***p<0.001, one-way ANOVA with Newman-Keulspost test (A, C–E). ***p<0.001, Student’s <i>t</i> test (B). The data are presented as the mean ± SEM. One representative from 3 independent experiments is shown. Ni, nicotine.