Conditioned medium from human B cells incubated with <i>L</i>. <i>infantum</i> amastigotes modulate CD4+ T-cell proliferation.

<p>Purified human CD25^-CD4⁺ T cells were first labeled with CFSE and treated as described in <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0003543#pntd.0003543.g006" target="_blank">Fig. 6</a>. After 5 days, cell proliferation was assessed by CFSE dilution and dead cells were excluded by 7-AAD staining. A) A representative histogram is shown for each tested condition. B) Proliferation index for experiments performed with CD25^-CD4⁺ T cells from 2 different donors incubated with cell-free supernatants from 6 or 7 different B-cell donors. Statistical significance was evaluated by two-tailed Student’s t-test.