Figure 4

RCMV induces inflammation in the aortic allografts with increased infiltration of macrophages. (A) Cross sections of RCMV-infected allografts 2 and 8 weeks post transplantation stained to detect RCMV early/late antigen (R44-encoded protein). RCMV-infected cells were localized mainly in the adventitia and intima of the allograft. Brown, cells positive for RCMV. I, intima; M, media; A, adventitia. (B) Cross sections of RCMV-infected allografts and uninfected allografts (controls) at 2 and 8 weeks post transplantation stained for CD68-positive macrophages. Brown indicates positive staining for CD68 that appears mainly in the intima and adventitia. I, intima; M, media; A, adventitia. (C) Fragment of a cross section of RCMV-infected allograft double immunostained to detect RCMV-infected CD68-positive macrophages. 80% of infiltrating CD68-positive macrophages were RCMV infected. Green, CD68-positive macrophages; blue, RCMV; red, nuclei. (D) Cross sections of RCMV-infected allografts and uninfected controls at 2 and 8 weeks post transplantation stained for CD45-positive leukocytes. Brown indicates positive staining for CD45 that appears mainly in the intima and adventitia. I, intima; M, media; A, adventitia. (E) Cross sections of RCMV-infected allografts and uninfected controls at 2 and 8 weeks post transplantation stained for CD3-positive lymphocytes. Brown indicates positive staining for CD3 that appears mainly in the adventitia. I, intima; M, media; A, adventitia. (F) Bar charts show a number of CD68- and CD45-positive leukocytes in the media and intima of RCMV-infected and uninfected allografts (controls). Infiltration of CD68-positive macrophages into the intima was 4-fold higher and 2-fold higher in the media of infected allografts compared to uninfected controls. At 8 weeks, there was a massive infiltration of macrophages in the adventitia. ***p < 0.001 vs. uninfected control at 2 weeks in intima; **p < 0.01 vs. uninfected control at 8 weeks in intima; *p < 0.05 vs. uninfected control at 8 weeks in media.