Figure 4.

Dependence of initiation of proliferation on the inoculum of M. tuberculosis. Bacterial cfu in the lung (A) and mediastinal lymph node (B) over the course of the infection after inocula of <15, 30, 100, or 700 bacteria per mouse. (B) Histograms are representative of P25TCR-Tg CD4⁺ T cell proliferation in the mediastinal lymph node 14 (left column) or 17 (right column) d after infection in mice that received the designated inocula. (C) Correlation of mediastinal lymph node bacterial burden and proliferation of P25TCR-Tg CD4⁺ T cells. Data are from three independent experiments, and include data from mice that received distinct inocula and that were harvested on various days after infection. (D) Correlation of lung and mediastinal lymph node cfu and P25TCR-Tg CD4⁺ T cell proliferation. Six mice with similar lung cfu and dissimilar mediastinal lymph node cfu are highlighted. Inset table shows the log₁₀ lung cfu (Lung), log₁₀ mediastinal lymph node cfu (LN), and the percentage of P25TCR-Tg CD4⁺ T cells that had undergone one or more cycles of proliferation in the mediastinal lymph node for each of the highlighted mice.