Title Page
Contents
ABSTRACT 13
국문초록 15
CHAPTER 1. Introduction 18
1.1. Prion 18
1.1.1. Prion structure 19
1.1.2. Prion pathogenesis 21
1.1.3. Prion and immune cells 22
1.1.4. Phenotype of Prnp⁰/⁰ mice[이미지참조] 23
1.2. Cancer 24
1.3. Regulatory T(Treg) cell 26
1.3.1. Treg cell development 28
1.3.2. Mechanisms of immune suppression by Treg cells 30
1.4. Inflammation 32
1.5. Colitis 33
1.5.1. Signs and symptoms of colitis 34
1.5.2. Diagnosis and treatment of colitis 34
1.5.3. DSS-induced colitis model 35
CHAPTER 2. Material and method 36
2.1. Mice 36
2.2. Cancer development 36
2.3. Dextran sulfate sodium (DSS)-induced colitis 37
2.4. Quantitative real-time PCR analysis 38
2.5. Confocal microscopy 39
2.6. Flow cytometry 40
CHAPTER 3. Results 41
3.1. Effect of PrPC in cancer and Treg cell activation[이미지참조] 41
3.1.1. Association of the PrPC expression with lung cancer development[이미지참조] 41
3.1.2. Increase of Treg cell numbers in WT and Tga20 mice 43
3.1.3. Upregulation of TGF-β and PD-L1 expression in Tga20 mice 46
3.1.4. No association between PrPC expression and NK or CD8 T cell numbers[이미지참조] 48
3.2. Effect of PrPC in inflammation and Treg cell activation[이미지참조] 50
3.2.1. Progression of acute DSS colitis in WT and Prnp⁰/⁰ mice[이미지참조] 50
3.2.2. Increase of Inflammation-related cells and pro-inflammatory cytokine expression in Prnp⁰/⁰ mice with acute DSS colitis[이미지참조] 53
3.2.3. Decreased activity of Treg cells in Prnp⁰/⁰ mice with acute DSS colitis[이미지참조] 56
3.2.4. Progression of chronic DSS colitis in WT and Prnp⁰/⁰ mice[이미지참조] 59
3.2.5. Increase of pro-inflammatory cytokine expression in Prnp⁰/⁰ mice with chronic DSS colitis[이미지참조] 61
3.2.6. Decreased activity of Treg cells in Prnp⁰/⁰ mice with chronic DSS colitis[이미지참조] 63
CHAPTER 4. Discussion 64
REFERENCES 68
[Table 2-1] List of primer sequences used for quantitative real-time PCR. 38
[Figure 1-1] The structure of PrPC and PrPSc.[이미지참조] 20
[Figure 1-2] Recruitment of Treg cells in the tumor microenvironment by chemokine/chemokine receptor interaction. 25
[Figure 1-3] Balance of Treg cells and effector cells. 27
[Figure 1-4] The schematic representation of Treg cell development. 29
[Figure 1-5] Immune suppression mechanisms by Treg cells. 31
[Figure 3-1] The end-stage of metastatic lung cancer caused by B16F10 melanoma cells of Prnp⁰/⁰, WT and Tga20 mice. (A) Images of lung cancer. (a) WT control...[이미지참조] 42
[Figure 3-2] Low power confocal images of white pulp regions of spleens from Prnp⁰/⁰ (A,B), WT (C,D), and Tga20 (E,F) mice. CD3: blue for T cells, IgM: red...[이미지참조] 44
[Figure 3-3] FACS analysis of Treg cell population in the spleens from Prnp⁰/⁰, WT and Tga20 mice. Results of flow cytometry analysis of CD25 and Foxp3...[이미지참조] 45
[Figure 3-4] mRNA expression of TGF-β and PD-L1 in the spleens from Prnp⁰/⁰, WT and Tga20 mice. (A) mRNA expression for Tgfb. (B) mRNA expression for...[이미지참조] 47
[Figure 3-5] FACS analysis of NK cells and CD8 T cells in the spleens from Prnp⁰/⁰, WT and Tga20 mice. (A) DX5⁺ NK cells (%). (B) CD3⁺ CD8⁺ T cells (%)....[이미지참조] 48
[Figure 3-6] mRNA expression of perforin and granzyme B in the spleens from Prnp⁰/⁰, WT and Tga20 mice. (A) mRNA expression for perforin. (B) mRNA...[이미지참조] 49
[Figure 3-7] Change of body weight in WT and Prnp⁰/⁰ mice with acute DSS colitis. Results of taking 2% DSS solution for 7 days. total n=9 for each group.[이미지참조] 51
[Figure 3-8] Change of MLN size in WT and Prnp⁰/⁰ mice with acute DSS colitis. Red line represents the MLNs.[이미지참조] 51
[Figure 3-9] Change of spleen weight in WT and Prnp⁰/⁰ mice with acute DSS colitis. Results of percentage of spleen to body weight. Error bars display mean...[이미지참조] 52
[Figure 3-10] FACS analysis of inflammation-related cells in MLNs from WT and Prnp⁰/⁰ mice with acute DSS colitis. (A) Flow cytometric analysis of...[이미지참조] 54
[Figure 3-11] mRNA expression of pro-inflammatory cytokines in MLNs and spleens from WT and Prnp⁰/⁰ mice with acute DSS colitis. (A) mRNA expression...[이미지참조] 55
[Figure 3-12] FACS analysis of Treg cell activity in MLNs from WT and Prnp⁰/⁰ mice with acute DSS colitis. Flow cytometric analysis of (GITR or OX40) and...[이미지참조] 57
[Figure 3-13] mRNA expression of TGF-β and IL-10 in MLNs and spleens from WT and Prnp⁰/⁰ mice with acute DSS colitis. (A) mRNA expression in MLNs. (B)...[이미지참조] 58
[Figure 3-14] Change of body weight in WT and Prnp⁰/⁰ mice with chronic DSS colitis. Results of 3 cycles of (administration of 2% DSS solution for 7 days and...[이미지참조] 59
[Figure 3-15] Change of spleen weight in WT and Prnp⁰/⁰ mice with chronic DSS colitis. Result of percentage of spleen to body weight. Error bars display mean...[이미지참조] 60
[Figure 3-16] mRNA expression of pro-inflammatory cytokines in MLNs and spleens from WT and Prnp⁰/⁰ mice with chronic DSS colitis. (A) mRNA...[이미지참조] 62
[Figure 3-17] FACS analysis of Treg cell activity in MLNs from WT and Prnp⁰/⁰ mice with chronic DSS colitis. Flow cytometric analysis of GITR and CD25...[이미지참조] 63