Acute CVB3 infection in juvenile mice induced an increase in myocardial Sca-1 expression.

<p>Three day-old mice were infected with eGFP-CVB3 (10⁵ pfu IP) or mock-infected, and hearts were isolated at 2 days PI. Paraffin-embedded sections of heart tissue were deparaffinized and stained using antibodies against Sca-1. Alternatively, hearts were mechanically dissociated and cells were fixed in 10% formalin in PBS for FACS analysis <i>(A)</i> An increase in Sca-1⁺ cells (green) was observed in the heart following infection. <i>(B)</i> FACS analysis confirmed an elevation of Sca-1⁺ cells in the heart following infection. Primarily resident Sca-1⁺, but also blood-derived (CD45⁺) Sca-1⁺ cells were shown to increase in number in the heart following infection. Representative flow cytometric results for three infected or mock-infected mice are shown.