Nicotine Inhibits Memory CTL Programming
Figure 4
Nicotine impairs memory CTL programming.
A–D: Purified OT-I cells were cultured for 3 days with 3SI in the presence of nicotine at different concentrations. Three days after stimulation, CTLs were harvested and transferred into B6 recipients at a concentration of 106 cells/mouse. At day 30 post-transfer, memory CTLs were examined in the spleen. A. Comparison of percentage of OT-I cells in total CD8 cells in spleens. B. Comparison of number of memory CTLs in spleen. C. Comparison of phenotype of memory CTLs in spleen. The dashed line indicates gating for positive population, and endogenous CD8 T cell in recipients are shown as control. D. Recipient mice were challenged with LM-OVA as previously reported [25] and protection was compared to 0.1 µg/ml nicotine treatment at 3 days after challenge in spleen. “Positive” control mice were VV-OVA infected memory B6 mice. B6 mice were first transferred with 105/mouse naïve OT1 cells, which were infected with VV-OVA the next day, then sat for 30 days. These VV-OVA infected memory mice have effective memory CTLs against LM-OVA rechallenge, as we reported previously [22]. E–F: In vitro stimulated cells with 3SI in the presence or absence of nicotine at 10 µM were transferred into B6 mice for 30 days, and total number of memory OT-I was examined in peripheral lymph nodes, spleen, bone marrow and lung. E. Comparison of total memory CTLs from different tissues. F. Comparison of memory CTL distribution in tissues. The percentage was calculated by dividing the number of memory OT-I in each individual tissue by the total memory OT-I from examined tissues in each mouse. The experiment was repeated three times and similar results were obtained. Asterisks indicate statistical significance. *, P<0.05; **, P<0.01; ***, P<0.001.
