Figure 4. LPS enhanced memory CD8⁺ T cells survival, but not homeostatic turnover.

B6 mice containing a small number of naive P14 CD8⁺ T cells were immunized with either DC-33 alone (grey) or in combination with LPS (dashed) or MPLA (black). A) Line graph shows the numbers of KLRG1^loIL-7R^hi P14 CD8⁺ T cells on day 7 and 42 post immunization. Note the increased rates of death within this subset of effector cells during the contraction phase in MPLA-primed mice. (B-D) At day 7 post immunization, equal numbers of effector P14 CD8⁺ T cells (1×10⁶ cells/mouse) from each group were CFSE-labeled and adoptively transferred into naïve B6 recipients. (B) P14 CD8⁺ T cells recovered from spleens and lymph nodes on day 35 post-transfer were enumerated and plotted in the bar graphs. (C) CFSE dilution was analyzed in P14 CD8⁺ T cells 35 days later by flow cytometry and plotted in histograms (DC alone=grey shaded, DC+LPS=dashed line and MPLA=black line). Data shown are representative of at least two independent experiments (* denotes to p<0.05).