Alteration in pro-inflammatory cytokine profile
We also examined the effect of bacterial treatment on expression of pro-inflammatory cytokines. As depicted in figure 6, administration of bacteria bearing construct at concentrations equal to 108 cfu/g to the mice bearing spontaneous breast tumors, resulted in a significant decline in expression of pro-inflammatory cytokines, including IL-1α, IL-1β, IL-6, IL-12, TNF-α, G-CSF and GM-CSF while increasing expression of IL-17A, IL-10 and INF-γ compared to the PBS receiving group. No significant changes were observed in expression profile of IL-2 pro-inflammatory cytokine. Therefore, treatment with bacteria bearing cardiac hormone expressing construct could increase expression of some of the most important cytokines of both Th1 and Th2 cells (INF-γ and IL-10 respectively).
Immunohistochemistry, quantification of micro-vessel density and H&E staining results
As illustrated in Figure 7, MMP9 expression was significantly decreased in mice receiving bacteria bearing construct at concentrations equal to 108 cfu/g compared to PBS receiving group. Furthermore, expression of VEGF receptor 2 (VEGFR2) and Ki-67 were also significantly decreased in response to therapy. Also, comparing state of CD31 expression as a marker of micro-vessels density demonstrated a significant decline in mice receiving bacteria bearing construct at concentrations equal to 108 cfu/g compare to control group. Finally, the number of TILs and CD8+ TILs were significantly increased in mice treated with bacteria bearing construct at concentration equal to 108 cfu/g.