Protective effects of β-glucan on intestinal immune responses following chemotherapy or acute high-intensity exercise in mice

다국어 초록 (Multilingual Abstract)

In contemporary exercise immunology, there is growing consensus around the hypothesis that the decreases in blood immune cell count following high-intensity exercise reflects a redistribution of immune cells to peripheral organs, including the gut. This study aimed to investigate whether such immune cell alterations occur in the gut following high-intensity exercise. Mice were subjected to swimming with tail loading until exhaustion, and blood and the Peyer’s patches (PP) were collected 1 h post-exercise. The exercise group exhibited elevated levels of lipopolysaccharides and FITC-dextran in the blood. A notable increase in phagocytes, specifically CD11c+ cells and F4/80+ cells, as well as CD80+CD11c+ and CD69+CD3+ cells, was observed in the PP, indicating a response of both innate and adaptive immune cells to the changing gut environment. Additionally, there was an upregulation of the frequency of IL-17+CD4+CD3+ cells and increased expression of Th17-related genes, including IL-17F, IL-22, IL-23, CCL20, G-CSF and IFN-γ. In summary, a single strenuous exercise session induced changes in phagocytes and Th17 cells within the gut. These findings underscore the need for strategic measures to mitigate the risk of inflammatory gut conditions in elite athletes engaged in regular high-intensity training.
Keywords: High-intensity exercise, Peyer’s patches, Th17 cells, Phagocytes

다국어 초록 (Multilingual Abstract)

High-intensity exercise is integral to the training regimen of elite athletes, yet it often leads to gastrointestinal symptoms attributed to hypoperfusion and subsequent gut bacteria invasion. Yeast β-glucan (YBG), a natural product known for its reported protective effects on the intestine and immune system. This study focuses on examining its impact on intestinal damage and immune disruption post high-intensity exercise. Mice received oral administration of 200 μg/kg YBG for two weeks before exhaustive swimming with tail loading. Blood and Peyer’s patches (PP) were collected 1 hour post-exercise. YBG administration demonstrated a protective role in the gut barrier by reducing serum lipopolysaccharide concentration in the exercise group. In the PP, YBG mitigated inflammation, evident in the decreased proportion of Ly6G+ neutrophils. Concerning dendritic cells (DCs), there was an increase in the percentage of CD11c+ cells, while CD80+CD11+ cell levels decreased, indicating a lower DC activation status. Although the frequency of CD3+ T cells remained unchanged, their proliferative capacity diminished. Collectively, YBG attenuated the gut inflammatory response induced by acute exercise, suggesting its potential benefits as a supplement for elite athletes who routinely engage in high-intensity exercise.
Keywords: High-intensity exercise, Yeast β-glucan, Peyer’s patches, Immune cells, Intestine

국문 초록 (Abstract)

현대 운동 면역학에서는 고강도 운동에 따른 혈액 면역 세포 수의 감소가 장을 포함한 말초 기관으로의 면역 세포의 재분배를 반영한다는 가설에 대한 공감대가 높아지고 있다. 본 연구는 이러한 가설을 기반으로 하여 고강도 운동 후 장에서의 면역 세포 변화를 조사했다. 마우스는 꼬리에 무게 추를 달고 탈진할 때까지 수영을 하였고, 운동 종료 1시간 후에 혈액과 파이어판을 수집했다. 운동군은 혈액 내 LPS와 FITC-dextran의 수치가 상승한 것으로 나타났다. 또한, 파이어판에서 CD11c+, F4/80+ 인 식세포와 CD80+CD11c+ 및 CD69+CD3+ 세포의 현저한 증가가 관찰되었다. 이는 변화하는 장 환경에 대한 선천성 및 적응성 면역 세포의 반응으로 해석된다. 더불어 IL-17+CD4+CD3+ 세포의 빈도가 상향 조절되었고 IL-17F, IL-22, IL-23, CCL20, G-CSF, IFN-γ를 포함한 Th17 관련 유전자의 발현이 증가했다. 이러한 결과는 한 번의 강도 높은 운동이 장 내 식세포와 Th17 세포의 변화를 유도하는 것을 의미한다. 이러한 발견은 정기적인 고강도 훈련에 참여하는 엘리트 운동선수가 염증성 장 질환의 위험을 완화하기 위한 전략적 조치의 필요성을 강조한다.
키워드: 고강도 운동, 파이어판, Th17 세포, 포식세포

국문 초록 (Abstract)

고강도 운동은 엘리트 운동선수의 필수적인 훈련 방법이지만, 종종 저관류로 인한 위장 증상과 그에 따른 장내 미생물 침입이 유발된다. 효모 유래 베타글루칸 (YBG)은 장과 면역계에 보호 효과가 있다고 보고된 천연물이다. 본 연구는 YBG의 투여가 고강도 운동 후 장 손상 및 면역계에 미치는 영향을 중점적으로 조사하였다. 마우스에게 2주 동안 YBG을 200μg/kg으로 경구 투여한 후 1회 고강도 운동을 실시하였다. 고강도 운동 1시간 후에 마우스의 혈액 및 파이어판(PP)을 분리하였다. YBG 투여는 운동 후에 증가한 혈청의 지질다당류 농도를 감소시켜 장 장벽을 보호하는 역할을 하는 것으로 나타났다. PP에서는 YBG가 염증을 완화시켰는데, 이는 Ly6G+ 호중구의 비율이 감소한 것으로 나타났다. 수지상 세포(DC)에 관해서는 CD11c+ 세포의 비율이 증가한 반면 CD80+CD11+ 세포 수준은 감소하여 낮은 DC 활성화 상태를 나타냈다. CD3+ T 세포의 비율은 변하지 않았지만 증식 능력은 감소했다. 종합적으로, YBG는 단발성 고강도 운동으로 유발된 장 염증 반응을 완화시켰으며, 이는 정기적으로 고강도 운동에 참여하는 엘리트 운동선수를 위한 보충제로서의 잠재적 이점을 시사한다.
키워드: 고강도 운동, 이스트 베타글루칸, 파이어판, 면역 세포, 장

국문 초록 (Abstract)

Euglena gracilis (EUG)는 베타글루칸인 paramylon이 과립 형태로 풍부하게 저장되어 있는 식품 보충제이다. 이 연구의 목적은 EUG가 항암제 투여 부작용인 백혈구 감소증과 세균불균형을 개선할 수 있는지 확인하는 것이었다. 젬시타빈 (GEM) 항암제를 투여 전에 마우스에게 EUG를 경구 투여했다. 혈액 세포 수, 비장 내 백혈구 비율, 비장 세포가 생산하는 granulocyte/macrophage colony-stimulating factor(GM-CSF)와 대변 미생물군집에 대한 분석이 수행했다. 단일 젬시타빈 투여 후에 전체 백혈구, 호중구 및 단핵구의 회복이 가속화되었으며, 4회 젬시타빈 투여 후에는 더욱 빠른 림프구 회복 속도가 관찰되었다. GEM과 EUG/GEM 군의 비장에서 T, B 또는 골수 세포의 비율이나 Dectin-1의 발현 차이가 없었다. EUG/GEM 군에서는 LPS로 자극된 비장세포에서 GM-CSF 생산이 증가했다. 또한, Next-generation sequencing 결과에서는 젬시타빈으로 인한 장내미생물 불균형이 EUG에 의해 완화되었다. 이 연구는 EUG 유래 베타글루칸이 항암제 투여로 인한 부작용을 개선할 수 있는 프리바이오틱스뿐만 아니라 생물학적 반응 조절제 역할을 할 수 있다는 가능성을 제시했다.
키워드: 베타글루칸, 항암화학치료, 장내 미생물 불균형, 유글레나, 백혈구감소증, 파라밀론

다국어 초록 (Multilingual Abstract)

Euglena gracilis (EUG) is a food supplement rich in β-glucans, which are stored in the form of granules called paramylon. The purpose of this study was to see if EUG could improve chemotherapy-induced leukocytopenia and dysbiosis. Mice were orally administered EUG prior to gemcitabine treatment. Analyses of the blood cell count, leukocyte population in the spleen, granulocyte/macrophage-colony-stimulating factor (GM-CSF) production by splenocytes, and fecal microbiome were conducted. The recovery of total leukocytes, neutrophils, and monocytes was accelerated after a single gemcitabine treatment. A more rapid lymphocyte recovery rate was observed after four gemcitabine treatments. No difference was observed in the percentage of T, B, or myeloid cells or in the expression of Dectin-1 in the spleens of the gemcitabine and EUG/gemcitabine groups. The EUG/gemcitabine group showed an enhanced GM-CSF production by lipopolysaccharides-stimulated splenocytes. Next-generation sequencing revealed that gemcitabine-induced dysbiosis was alleviated. This study demonstrated that EUG-derived β-glucans could act as a biological response modifier as well as prebiotics for ameliorating chemotherapy-induced adverse effects.
Keyword: β-glucans, Chemotherapy, Dysbiosis, Euglena gracilis, Leukocytopenia, Paramylon

목차 (Table of Contents)

• 1.Literature review 1
• 1.1 Introduction 2
• 1.2 Sources and Structure of β-Glucan 2
• 1.3 β-Glucan Receptors 3
• 1.3.1 Dectin-1 3
• 1.3.2 Complement receptor 3 4
• 1.3.3 Toll-like receptors 5
• 1.3.4 Langerin 5
• 1.3.5 Scavenger receptors 6
• 1.4 Anti-tumor and Immunomodulation Effects of β-Glucan 6
• 1.5 β-Glucan Effect as an Exercise Supplement 8
• 1.6 Conclusion 9
• 2. Oral administration of euglena gracilis paramylon ameliorates chemotherapy-induced leukocytopenia and gut dysbiosis in mice 10
• Abstract 11
• 2.1 Introduction 12
• 2.2 Materials and Methods 15
• 2.2.1 EUG preparation 15
• 2.2.2 Experimental animal 15
• 2.2.3 Blood cell analysis 15
• 2.2.4 Splenocyte preparation 16
• 2.2.5 Flow cytometry analysis 16
• 2.2.6 Cytokine analysis 16
• 2.2.7 Fecal sample preparation and DNA extraction 17
• 2.2.8 16S ribosomal DNA gene sequencing 17
• 2.2.9 Statistical analysis 18
• 2.3 Results 19
• 2.3.1 EUG accelerated the recovery of myeloid leukocyte suppression in blood following a single gemcitabine treatment 19
• 2.3.2 EUG did not affect the splenic immune cell population following a single gemcitabine treatment 22
• 2.3.3 EUG enhanced GM–CSF production via splenocytes from gemcitabine-treated mice 25
• 2.3.4 EUG accelerated the recovery of lymphocyte count suppression in the blood following multiple gemcitabine treatments 27
• 2.3.5 EUG altered gemcitabine-induced dysbiosis 30
• 2.4 Discussion 36
• Abstract in Korean 39
• 3. Heightened immune surveillance in the Peyer’s patches of mice following acute high-intensity endurance exercise 41
• Abstract 42
• 3.1 Introduction 43
• 3.2 Materials and Methods 45
• 3.2.1 Experimental animal 45
• 3.2.2 Exercise protocol 45
• 3.2.3 Blood samples 45
• 3.2.4 Measurement of intestinal permeability using FITC-dextran 46
• 3.2.5 Endotoxin quantification 46
• 3.2.6 PP cell isolation and cell counting 46
• 3.2.7 Flow cytometry analysis 47
• 3.2.8 Assessment of Phagocytosis in PP Cells 47
• 3.2.9 Real-time PCR 47
• 3.2.10 Statistical analysis 48
• 3.3 Results 49
• 3.3.1 Changes in blood cell ratio caused by high-intensity exercise 49
• 3.3.2 Increased intestinal permeability because of high-intensity exercise 52
• 3.3.3 Variations in the proportion of immune cells in PP after 1 hour of high-intensity exercise 54
• 3.3.4 Activated DC and T cells increased in PP 1 hour after high-intensity exercise 57
• 3.3.5 PP cells that were isolated 1 hour after high-intensity exercise exhibited enhanced phagocytic capability 59
• 3.3.6 Variation in the expression of Th17-related cytokines in PP 1 hour after high-intensity exercise 61
• 3.4 Discussion 63
• Abstract in Korean 66
• 4. Protective effects of yeast β-glucan administration on gut inflammatory response induced by acute exercise 68
• Abstract 69
• 4.1 Introduction 70
• 4.2 Materials and Methods 72
• 4.2.1 Yeast β-glucan 72
• 4.2.2 Experimental animal 72
• 4.2.3 Experimental protocol 72
• 4.2.4 Endotoxin quantification 73
• 4.2.5 PP cell isolation and cell counting 73
• 4.2.6 Flow cytometry analysis 73
• 4.2.7 Analysis of PP Cell Proliferation 74
• 4.2.8 Statistical analysis 74
• 4.3 Results 75
• 4.3.1 The blood cell ratio of mice given Gemcitabine changed when different concentrations of YBG were administered 75
• 4.3.2 The administration of YBG protected against intestinal damage caused by high-intensity exercise 78
• 4.3.3 The administration of YBG affected changes in the proportion of immune cells in PP caused by high-intensity exercise 80
• 4.3.4 The β-glucan receptor Dectin-1's expression is altered by YBG administration following high-intensity exercise 82
• 4.3.5 Administration of YBG changed activation markers of DC after high-intensity exercise 84
• 4.3.6 YBG administration changed PP cell proliferation after high-intensity exercise 86
• 4.4 Discussion 88
• Abstract in Korean 90
• References 91
• List of Articles 109