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An effective cytokine adjuvant vaccine induces autologous T-cell response against colon cancer in an animal model

View Article: PubMed Central - PubMed

ABSTRACT

Background: Despite recent advances in early detection and improvements in chemotherapy for colon cancer, the patients still face poor prognosis of postoperative recurrence and metastasis, the median survival for patients with metastatic colorectal cancer is approximately 22–24 months. Some immunotherapeutic approaches had been attempted in colon cancer patients to significantly increase overall survival. A vaccine based approach has shown a novel direction for colon cancer prevention and therapy.

Methods: In this study, the experiments were designed including prevention and therapeutic stages in order to attain effect against tumor recurrence in clinical settings. The anti-tumor efficacy of a novel cytokine adjuvant vaccine that contained cytokines GM-CSF and IL-2 and inactivated colon CT26.WT whole cell antigen was evaluated in BALB/c mouse tumor models by measuring tumor growth post vaccination and the survival time of tumor-bearing mice, analyzing the expression and distribution of CD4, CD8, CD11c, CD80, CD86 and CD83 positive cells in control and treated mice by flow cytometry and immunochemistry. The tumor-specific cytotoxic T cells (CTL) were analyzed by tumor proliferation and the lactic dehydrogenates (LDH) release assays. IFN-γ, IL-2 and GM-CSF secretion in serum was assayed by ELISA.

Results: Our results suggested that cytokine adjuvant vaccine significantly inhibited tumor growth and extended the survival period at least 160d. It was found that the levels of CD8 + T and the tumor-specific cytotoxicity were significantly higher in prevention and treatment group vaccinated by cytokine adjuvant vaccine. CD8 + T cells play a key role in anti-tumor response.

Conclusions: The novel GM-CSF and IL-2 based adjuvant vaccine effectively activated autologous T-cell response and represented a promising immunotherapeutic approach for patients with colon cancer.

Electronic supplementary material: The online version of this article (doi:10.1186/s12865-016-0172-x) contains supplementary material, which is available to authorized users.

No MeSH data available.


Related in: MedlinePlus

Distribution of CD4+, CD8+, CD11c+, CD80+ and CD86+ cell populations in Lymph node and tumor tissue Panel A, represents the expression of CD4 (a), CD8 (b) and CD11c (c) as analyzed by IHC staining of LN isolated at different time points from tumor control or treatment group mice. Panel B, represents the expression of CD80 (a) and CD86 (b) as analyzed by IHC staining of LN isolated at different time points from tumor control or treatment group mice. The expression of these molecules was calculated by IHS. Panel C, represents the HE and anti-CD4 and -CD8 IHC staining of tumor tissues collected from different groups. The results were observed in (40 × 10) horizon. Data are represented as mean ± SD. Bar = 50 μm. *denotes p < 0.05, **denotes p < 0.01, ***denotes p < 0.001
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Fig5: Distribution of CD4+, CD8+, CD11c+, CD80+ and CD86+ cell populations in Lymph node and tumor tissue Panel A, represents the expression of CD4 (a), CD8 (b) and CD11c (c) as analyzed by IHC staining of LN isolated at different time points from tumor control or treatment group mice. Panel B, represents the expression of CD80 (a) and CD86 (b) as analyzed by IHC staining of LN isolated at different time points from tumor control or treatment group mice. The expression of these molecules was calculated by IHS. Panel C, represents the HE and anti-CD4 and -CD8 IHC staining of tumor tissues collected from different groups. The results were observed in (40 × 10) horizon. Data are represented as mean ± SD. Bar = 50 μm. *denotes p < 0.05, **denotes p < 0.01, ***denotes p < 0.001

Mentions: We next analyzed distribution of CD4, CD8, CD11c, CD80, CD86 and CD83 cells in the lymph nodes by IHC in order to confirm the FACS results (Fig. 5A, and B). Consistently, we confirmed that, as compared to the Tumor group, the samples in Treatment group had greatly higher expression of CD4, CD8 and CD11c, suggesting a strong immune response that induced by the vaccination in the Treatment group (Additional file 3: Figure S3). It is interesting to note that the expression of CD8 and CD11c in the Treatment group maintained significantly higher than that in the control group during the tested period of time (Fig. 5A b and c). The level of CD11c expression may represent the relative amount of mature DC and effective antigen presentation (Fig. 5Ac). In order to further confirm our results, specific surface molecules of CD80, CD86 and CD83 on DC cells were detected. The results showed that the different variable for three molecules (Fig. 5B and Additional file 4: Figure S4). There is no significant difference except for a few time points for the levels of CD83 during the Tumor group and Treatment group (Additional file 4: Figure S4C). However, the levels of CD80 were higher than the levels of CD86 in lymph nodes. Furthermore, the expressions of CD80 and CD86 in Treatment group were significantly higher than Tumor group especially on the back of a few time points the same as the results of CD11c (Fig. 5B a and b). The results suggested that GM-CSF could induce activation and maturation of DC and maintain at relevantly high levels during the course. These data suggested that the vaccine may induce the body to produce a stronger T cell response due to higher number of mature DCs in the lymph nodes.Fig. 5


An effective cytokine adjuvant vaccine induces autologous T-cell response against colon cancer in an animal model
Distribution of CD4+, CD8+, CD11c+, CD80+ and CD86+ cell populations in Lymph node and tumor tissue Panel A, represents the expression of CD4 (a), CD8 (b) and CD11c (c) as analyzed by IHC staining of LN isolated at different time points from tumor control or treatment group mice. Panel B, represents the expression of CD80 (a) and CD86 (b) as analyzed by IHC staining of LN isolated at different time points from tumor control or treatment group mice. The expression of these molecules was calculated by IHS. Panel C, represents the HE and anti-CD4 and -CD8 IHC staining of tumor tissues collected from different groups. The results were observed in (40 × 10) horizon. Data are represented as mean ± SD. Bar = 50 μm. *denotes p < 0.05, **denotes p < 0.01, ***denotes p < 0.001
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC5037582&req=5

Fig5: Distribution of CD4+, CD8+, CD11c+, CD80+ and CD86+ cell populations in Lymph node and tumor tissue Panel A, represents the expression of CD4 (a), CD8 (b) and CD11c (c) as analyzed by IHC staining of LN isolated at different time points from tumor control or treatment group mice. Panel B, represents the expression of CD80 (a) and CD86 (b) as analyzed by IHC staining of LN isolated at different time points from tumor control or treatment group mice. The expression of these molecules was calculated by IHS. Panel C, represents the HE and anti-CD4 and -CD8 IHC staining of tumor tissues collected from different groups. The results were observed in (40 × 10) horizon. Data are represented as mean ± SD. Bar = 50 μm. *denotes p < 0.05, **denotes p < 0.01, ***denotes p < 0.001
Mentions: We next analyzed distribution of CD4, CD8, CD11c, CD80, CD86 and CD83 cells in the lymph nodes by IHC in order to confirm the FACS results (Fig. 5A, and B). Consistently, we confirmed that, as compared to the Tumor group, the samples in Treatment group had greatly higher expression of CD4, CD8 and CD11c, suggesting a strong immune response that induced by the vaccination in the Treatment group (Additional file 3: Figure S3). It is interesting to note that the expression of CD8 and CD11c in the Treatment group maintained significantly higher than that in the control group during the tested period of time (Fig. 5A b and c). The level of CD11c expression may represent the relative amount of mature DC and effective antigen presentation (Fig. 5Ac). In order to further confirm our results, specific surface molecules of CD80, CD86 and CD83 on DC cells were detected. The results showed that the different variable for three molecules (Fig. 5B and Additional file 4: Figure S4). There is no significant difference except for a few time points for the levels of CD83 during the Tumor group and Treatment group (Additional file 4: Figure S4C). However, the levels of CD80 were higher than the levels of CD86 in lymph nodes. Furthermore, the expressions of CD80 and CD86 in Treatment group were significantly higher than Tumor group especially on the back of a few time points the same as the results of CD11c (Fig. 5B a and b). The results suggested that GM-CSF could induce activation and maturation of DC and maintain at relevantly high levels during the course. These data suggested that the vaccine may induce the body to produce a stronger T cell response due to higher number of mature DCs in the lymph nodes.Fig. 5

View Article: PubMed Central - PubMed

ABSTRACT

Background: Despite recent advances in early detection and improvements in chemotherapy for colon cancer, the patients still face poor prognosis of postoperative recurrence and metastasis, the median survival for patients with metastatic colorectal cancer is approximately 22&ndash;24 months. Some immunotherapeutic approaches had been attempted in colon cancer patients to significantly increase overall survival. A vaccine based approach has shown a novel direction for colon cancer prevention and therapy.

Methods: In this study, the experiments were designed including prevention and therapeutic stages in order to attain effect against tumor recurrence in clinical settings. The anti-tumor efficacy of a novel cytokine adjuvant vaccine that contained cytokines GM-CSF and IL-2 and inactivated colon CT26.WT whole cell antigen was evaluated in BALB/c mouse tumor models by measuring tumor growth post vaccination and the survival time of tumor-bearing mice, analyzing the expression and distribution of CD4, CD8, CD11c, CD80, CD86 and CD83 positive cells in control and treated mice by flow cytometry and immunochemistry. The tumor-specific cytotoxic T cells (CTL) were analyzed by tumor proliferation and the lactic dehydrogenates (LDH) release assays. IFN-&gamma;, IL-2 and GM-CSF secretion in serum was assayed by ELISA.

Results: Our results suggested that cytokine adjuvant vaccine significantly inhibited tumor growth and extended the survival period at least 160d. It was found that the levels of CD8&thinsp;+&thinsp;T and the tumor-specific cytotoxicity were significantly higher in prevention and treatment group vaccinated by cytokine adjuvant vaccine. CD8&thinsp;+&thinsp;T cells play a key role in anti-tumor response.

Conclusions: The novel GM-CSF and IL-2 based adjuvant vaccine effectively activated autologous T-cell response and represented a promising immunotherapeutic approach for patients with colon cancer.

Electronic supplementary material: The online version of this article (doi:10.1186/s12865-016-0172-x) contains supplementary material, which is available to authorized users.

No MeSH data available.


Related in: MedlinePlus