Figure 3.

T cells and macrophages infiltrate into cardiac tissue of rats injected with streptococcal recombinant proteins. Rat hearts were stained using antibodies against CD3 to detect infiltrating T cells and CD68 to detect macrophages (arrows). Rats injected with GAS rM5 and SDSE M protein had significantly increased infiltration of CD3⁺ T cells and CD68⁺ macrophages. By contrast, control rats injected with PBS had no evidence of infiltration of CD3⁺ T cells or macrophages. Representative microscopic images of myocardium and valves from an age‐matched rat injected with GAS rM5 and SDSE Stg480. Both CD3⁺ T cells and CD68⁺ macrophages were observed in all cardiac tissues collected from three individual age‐matched rats injected with GAS rM5 (n = 3) and SDSE Stg480 (n = 3). Bars = 50 μm. GAS, group A streptococcus; PBS, phosphate‐buffered saline; SDSE, Streptococcus dysgalactiae subspecies equisimilis. [Colour figure can be viewed at wileyonlinelibrary.com]