Abstract
Background:
TFF1 deficiency induces a mucosal pro-inflammatory phenotype that contributes to gastric tumorigenesis in mouse and human.
Methods:
We utilized the
Tff1
-KO mouse model to assess the impact of TFF1 loss on immune cells infiltration in the stomach. We used single cell suspension, flow cytometry, immunohistochemistry, and quantitative PCR (qPCR) assays.
Results:
The
Tff1
-KO gastric mucosa demonstrated high chronic inflammatory scores (score: 3-4) at age 2 months, which exacerbated at age 8 months (score: 4-6). We next used single-cell suspensions for flow cytometry analysis of total leukocytes (CD45+ cells), total T lymphocytes (CD45+CD3+cells), T cell subsets (CD4+, CD8+, and CD3+CD4-CD8-cells), and monocytes/macrophages (CD45+F4/80+cells). The results demonstrated an age-dependent (2 → 8 month age) significant increase of leukocytes (
p<0.05
), T cells (
p<0.05
), and monocytes/macrophages (
p<0.001
) in the gastric mucosa of the
Tff1
-KO mice, as compared to
Tff1
-WT. A similar increase was observed in blood samples (
p<0.05
). Using ionomycin to activate CD4
+
splenocytes, the results indicated that
Tff1
-KO CD4
+
splenocytes secreted higher levels of IL-17A (
p<0.05
at 2 and
p<0.001
at 8 months) and IL-17F (
p
<0.05 at 2 and 8 months) than
Tff1
-WT splenocytes. Conversely,
Tff1
-KO CD8
+
-cells secreted less IL-17F, but comparable levels of IL-17A. In addition, we detected a significant upregulation of
Il-17
mRNA expression in gastric tissues in the
Tff1
-KO, as compared to
Tff1
-WT (
p<0.001
).
Conclusions:
The results identify TFF1 loss as a major pro-inflammatory step that modulates the tumor microenvironment and immune cell infiltration in the stomach. Furthermore, the data suggest that the increase of IL-17A and IL-17F in Th17 cells, derived from CD4
+
T cells, reflects the chronic inflammation in gastric mucosa, whereas the absence of change of IL-17A and decrease of IL-17F in CD8
+
Tc17 cells suggest loss of cytotoxic function of CD8
+
Tc17 cells during gastric tumorigenesis of the
Tff1
-KO mice.
