Mast Cells Modulate Acute Toxoplasmosis in Murine Models

The role of mast cells (MCs) in Toxoplasma gondii infection is poorly known. Kunming outbred mice were infected intraperitoneally with RH strain T. gondii, either treated with compound 48/80 (C48/80, MC activator) or disodium cromoglycate (DSCG, MC inhibitor). Compared with infected controls, infected mice treated with C48/80 exhibited significantly increased inflammation in the liver (P \u3c 0.01), spleen (P \u3c 0.05), and mesentery (P \u3c 0.05) tissues, higher parasite burden in the peritoneal lavage fluids (P \u3c 0.01), and increased levels of mRNA transcripts of T. gondii tachyzoite surface antigen 1 (SAG1) gene in the spleen and liver tissues (P \u3c 0.01), accompanied with significantly increased Th1 cytokine (IFN-γ, IL-12p40, and TNF-α) (P \u3c 0.01) and decreased IL-10 (P \u3c 0.01) mRNA expressions in the liver, and increased IFN-γ (P \u3c 0.01) and IL-12p40 (P \u3c 0.01) but decreased TNF-α (P \u3c 0.01) and IL-4 (P \u3c 0.01) in the spleens of infected mice treated with C48/80 at day 9-10 p.i. Whereas mice treated with DSCG had significantly decreased tissue lesions (P \u3c 0.01), lower parasite burden in the peritoneal lavage fluids (P \u3c 0.01) and decreased SAG1 expressions in the spleen and liver tissues (P \u3c 0.01), accompanied with significantly increased IFN-γ (P \u3c 0.01) and IL-12p40 (P \u3c 0.05) in the liver, and decreased IFN-γ (P \u3c 0.05) and TNF-α (P \u3c 0.01) in the spleens; IL-4 and IL-10 expressions in both the spleen and liver were significantly increased (P \u3c 0.01) in the infected mice treated with DSCG. These findings suggest that mediators associated with the MC activation may play an important role in modulating acute inflammatory pathogenesis and parasite clearance during T. gondii infection in this strain of mice. Thus, MC activation/inhibition mechanisms are potential novel targets for the prevention and control of T. gondii infection

Tumor budding of cervical squamous cell carcinoma: epithelial-mesenchymal transition-like cancer stem cells?

Recent evidence indicates that cancer stem cells (CSCs) are the origin of cancers. Scientists have identified CSCs in various tumors and have suggested the existence of a variety of states of CSCs. The existence of epithelial–mesenchymal transition (EMT)-like CSCs has been confirmed in vitro, but they have not been identified in vivo. Tumor budding was defined as single cell or clusters of ≤ 5 cells at the invasive front of cancers. Such tumor budding is hypothesized to be closely related to EMT and linked to CSCs, especially to those migrating at the invasive front. Therefore, tumor budding has been proposed to represent EMT-like stem cells. However, this hypothesis has not yet been proven. Thus, we studied the expression of EMT markers, certain CSC markers of tumor budding, and the tumor center of cervical squamous cell carcinoma (CxSCC). We performed tissue chip analyses of 95 primary CxSCCs from patients. Expression of EMT and CSC markers (E-cadherin, β-catenin, vimentin, Ki67, CD44, SOX2 , and ALDH1A1) in a set of tumor samples on tissue chips (87 cases of tumor budding/the main tumor body) were evaluated by immunohistochemistry. We found that the cell-membranous expression of β-catenin was stronger in the main tumor body than in tumor buds. Compared with the main tumor body, tumor buds had reduced proliferative activity as measured by Ki67. Moreover, vimentin expression was high and E-cadherin expression was low in tumor buds. Expression of EMT-related markers suggested that tumor buds were correlated with EMT. We noted that CxSCC tumor buds had a CD44negative/low/SOX2high/ALDH1A1high staining pattern, indicating that tumor buds of CxSCC present CSC-like immunophenotypic features. Taken together, our data indicate that tumor buds in CxSCC may represent EMT-like CSCs in vivo

Mast cells modulate acute toxoplasmosis in murine models.

The role of mast cells (MCs) in Toxoplasma gondii infection is poorly known. Kunming outbred mice were infected intraperitoneally with RH strain T. gondii, either treated with compound 48/80 (C48/80, MC activator) or disodium cromoglycate (DSCG, MC inhibitor). Compared with infected controls, infected mice treated with C48/80 exhibited significantly increased inflammation in the liver (P < 0.01), spleen (P < 0.05), and mesentery (P < 0.05) tissues, higher parasite burden in the peritoneal lavage fluids (P < 0.01), and increased levels of mRNA transcripts of T. gondii tachyzoite surface antigen 1 (SAG1) gene in the spleen and liver tissues (P < 0.01), accompanied with significantly increased Th1 cytokine (IFN-γ, IL-12p40, and TNF-α) (P < 0.01) and decreased IL-10 (P < 0.01) mRNA expressions in the liver, and increased IFN-γ (P < 0.01) and IL-12p40 (P < 0.01) but decreased TNF-α (P < 0.01) and IL-4 (P < 0.01) in the spleens of infected mice treated with C48/80 at day 9-10 p.i. Whereas mice treated with DSCG had significantly decreased tissue lesions (P < 0.01), lower parasite burden in the peritoneal lavage fluids (P < 0.01) and decreased SAG1 expressions in the spleen and liver tissues (P < 0.01), accompanied with significantly increased IFN-γ (P < 0.01) and IL-12p40 (P < 0.05) in the liver, and decreased IFN-γ (P < 0.05) and TNF-α (P < 0.01) in the spleens; IL-4 and IL-10 expressions in both the spleen and liver were significantly increased (P < 0.01) in the infected mice treated with DSCG. These findings suggest that mediators associated with the MC activation may play an important role in modulating acute inflammatory pathogenesis and parasite clearance during T. gondii infection in this strain of mice. Thus, MC activation/inhibition mechanisms are potential novel targets for the prevention and control of T. gondii infection

Mice survival after infection with 10² RH tachyzoites of <i>T</i>.

<div><p><b><i>gondii</i></b>. </p> <p>Survival of naïve mice treated with PBS (open square, n=8); uninfected mice treated with C48/80 (dash, n=8); uninfected mice treated with DSCG (open upright triangle, n=8); <i>T. gondii</i>-infected control mice (filled square, n=7), <i>T. gondii</i>-infected mice with C48/80 treatment (asterisk, n=9), and <i>T. gondii</i>-infected mice with DSCG treatment (filled upright triangle, n=8). The mice were monitored for survival on a daily basis until the termination of the experiment. </p></div

Cytokine mRNA expressions in livers from different groups i.p. inoculated with 10²<i>T</i>.

<div><p><b><i>gondii</i> RH strain tachyzoites at 9-10 days p.i., using qRT-PCR</b>. </p> <p>There were 4 mice per group, and the data are representative of two experiments. Symbols indicate statistically significant differences (<i>P</i> < 0.01) for comparison with the uninfected control mice (**) and the infected controls (§), and statistically significant differences (<i>P</i> < 0.05) for comparison with the infected controls (#).</p></div

The mesentery histopathology of <i>T</i>.

<div><p><b><i>gondii</i>-infected mice from different groups</b>. </p> <p>Infected mice i.p. inoculated with 10² RH tachyzoites of <i>T. gondii</i> were killed at 9-10 days p.i. (A) Representative microscopic pictures show sections from uninfected mouse treated with PBS (a), <i>T. gondii</i>-infected control mouse (b), <i>T. gondii</i>-infected mouse treated with C48/80 (c), and <i>T. gondii</i>-infected mouse treated with DSCG (d). Tachyzoites were indicated with arrows. H&E stain. (B) Histological score analysis of mesentery tissues. There were 4 mice per group, and the data are representative of two experiments. *, <i>P</i> < 0.05; **, <i>P</i> < 0.01 (compared to control). </p></div

The liver histological analysis of <i>T</i>.

<div><p><b><i>gondii</i>-infected mice from different groups</b>. </p> <p>Infected mice i.p. inoculated with 10² RH tachyzoites of <i>T. gondii</i> were killed at 9-10 days p.i. (A) Representative microscopic pictures show sections from uninfected mouse treated with PBS (a and b), infected control mouse (c and d), infected mouse treated with C48/80 (e and f), and infected mouse treated with DSCG (g and h). Tachyzoites were indicated with arrows. H&E stain. (B) Quantitative analysis of the number of inflammatory foci per field in liver sections from different groups. There were 4 mice per group, and the data are representative of two experiments. *, <i>P</i> < 0.05; **, <i>P</i> < 0.01 (compared to control). </p></div

Light photomicrographs of metachromatic MCs in mesenteries by toluidine blue staining.

<p>Infected mice i.p. inoculated with 10² RH tachyzoites of <i>T. gondii</i> from different groups were killed at 9-10 days p.i. Metachromatic MCs were evaluated in mesentery tissue from uninfected mouse treated with PBS (a), infected control mouse displaying mildly degranulated MCs (b), uninfected mouse treated with C48/80 (c) and infected mouse treated with C48/80 (d), both displaying degranulated MCs (arrows); uninfected mouse treated with DSCG (e) and infected mouse treated with DSCG (f), both displaying intact MCs. </p

Light photomicrographs of tryptase positive-MCs in mesenteries by immunofluorescence staining.

<p>Infected mice i.p. inoculated with 10² RH tachyzoites of <i>T. gondii</i> from different groups were killed at 9-10 days p.i. MCs were evaluated in mesentery tissue from uninfected mouse treated with PBS (a), infected control mouse displaying a degranulated MC (arrow) (b), uninfected mouse treated with C48/80 (c) and infected mouse treated with C48/80 (d), both displaying degranulated MCs (arrows); uninfected mouse treated with DSCG (e) and infected mouse treated with DSCG (f), both displaying intact MCs. </p

The spleen histological analysis of <i>T</i>.

<div><p><b><i>gondii</i>-infected mice from different groups</b>. </p> <p>Infected mice i.p. inoculated with 10² RH tachyzoites of <i>T. gondii</i> were killed at 9-10 days p.i. (A) Representative microscopic pictures show sections from uninfected mouse treated with PBS (a), <i>T. gondii</i>-infected control mouse (b), <i>T. gondii</i>-infected mouse treated with C48/80 (c), and <i>T. gondii</i>-mouse treated with DSCG (d). Tachyzoites were indicated with arrows. H&E stain. (B) Histological score analysis of spleen tissues. There were 4 mice per group, and the data are representative of two experiments. *, <i>P</i> < 0.05; **, <i>P</i> < 0.01 (compared to control). </p></div