Figure 2. L. monocytogenes capture instructs B cells to become antigen cross‐presenting cells.

• A–D
  CD80 (A, B) and CD86 (C, D) expression in B cells measured by flow cytometry on day 0 (non‐instructed; naïve) and day 2 after L. monocytogenes capture (BacB). (A and C) show representative experiments, (B and D) show the mean of at least three independent experiments.
• E, F
  H‐2K^b expression in B cells measured by flow cytometry on day 0 (naïve, pale gray) and day 1 after L. monocytogenes capture (BacB; dark gray). (E) Shows a representative experiment, (F) shows the mean of four independent experiments.
• G, H
  Expression of OVAp‐I in the context of H‐2K^b was detected by flow cytometry with anti‐OVAp‐I/H‐2K^b antibody, comparing BacB capturing Listeria‐WT (pale gray) and Listeria‐OVA (dark gray). (G) Shows a representative experiment, (H) shows the mean of two independent experiments.
• I
  Confocal images of Listeria‐WT (left panels) or Listeria‐OVA (right panels) BacB cells incubated with naïve OTI CD8⁺ T cells previously stained with CellTraceViolet (CV, red). Actin and CD3 fluorescence are shown on a “fire” scale and in cyan and white respectively in the merged images. Scale bars = 10 μm. *Indicate CD8⁺ T cells. Arrow points to the IS.
• J
  Quantification of actin accumulation at the IS on CD8⁺ T cells conjugated with Listeria‐WT or Listeria‐OVA BacB cells, analyzed using Synapse measures software from confocal images. Each dot corresponds to one IS. Three independent experiments were performed.

Data information: Column bars in the figure represent the mean. Error bars indicate the SD. Significant differences, analyzed by t‐test are represented by asterisk; *P < 0.05, ***P < 0.0005, non‐significant differences are marked as (ns).

Source data are available online for this figure.