Tentative T Cells: Memory Cells Are Quick to Respond, but Slow to Divide
Figure 5
Delayed accumulation of naive and memory CD4+ T cells occurs also in non-lymphoid tissues.
Mice containing 1.3×104 naïve (Thy1.1) and 1.3×104 memory (Ly5a) SMARTA CD4+ T cells were infected with LCMV and, at the indicated times after infection, lymphocytes from several lymphoid and non-lymphoid tissues were isolated and analyzed by flow cytometry. A. Dot plots show gated CD4+ T cells isolated from the tissues. The ovals identify the SMARTA cells (N, M = naïve & memory respectively), and the numbers indicate their percentage among all CD4 T cells (H = host CD4+ T cells). B. For each tissue, naïve and memory SMARTA CD4+ T cells are shown as percentages of all CD4+ T cells (two mice per time point). Note that both naïve and memory cells become prominent after day 4; however, the memory cells dominate the response in the non-lymphoid tissues.