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.