Follicular helper T cells infiltrate B cells follicles during the acute phase of <i>L. infantum</i> infection of rhesus macaques but the Tfh response is not sustained until the chronic phase.

<p>(<b>A</b>–<b>D</b>) Splenic tissue sections were stained with antibodies against CxCR5 (blue), CD4 (green) and PD-1 (red) and imaged by confocal microscopy. Shown are representative pictures of a naïve animal (A) and at 11 (B), 28 (C) and 250 (D) days after infection. (<b>E</b>) Inset from <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1004096#ppat-1004096-g008" target="_blank">figure 8C</a> as defined by the white square.