Modulation of dendritic cell activation by fibronectin in an inflammatory microenvironment
- 주제(키워드) fibronectin integrity , dendritic cells , lipopolysacchide-induced inflammation , immune regulation
- 발행기관 아주대학교 일반대학원
- 지도교수 Jong-Young Kwak
- 발행년도 2026
- 학위수여년월 2026. 8
- 학위명 석사
- 학과 및 전공 일반대학원 의학과
- 실제URI http://www.dcollection.net/handler/ajou/000000036652
- 본문언어 영어
- 저작권 아주대학교 논문은 저작권에 의해 보호받습니다.
초록/요약
The extracellular matrix （ECM） is increasingly recognized as an active regulator of immune responses in addition to its structural role in tissues. Among ECM components, fibronectin （FN） undergoes changes during inflammation; however, the impact of FN integrity on dendritic cell （DC） activation remains incompletely understood. In this study, we investigated the effects of intact FN and FN fragments on bone marrow-derived dendritic cell （BMDC） activation under inflammatory conditions. Intact FN significantly suppressed lipopolysaccharide （LPS）-induced BMDC activation, as evidenced by reduced cluster of differentiation 86 expression and decreased production of tumor necrosis factor-alpha and interleukin-6. In contrast, a commercially available 120-kDa FN fragment, selected based on fragment sizes detected following LPS-induced cell- mediated FN degradation in vitro, did not retain these inhibitory effects. In vivo transient changes in splenic FN were observed following LPS administration and were accompanied by increased DC activation as well as macrophage （Mφ） and neutrophil recruitment. To further examine the relationship between inflammatory cells, FN-containing ECM, and DC activation, an FN- collagen gel model was established. Within this system, the suppressive effect of the FN-collagen gel on BMDC activation was diminished in the presence of Mφ or neutrophils under LPS stimulation. Collectively, these findings indicate that the immunoregulatory effects of FN on DC activation depend on its structural integrity and suggest that inflammation-associated alterations in FN may influence ECM-mediated regulation of DC activation during inflammatory responses.
more초록/요약
세포외기질（extracellular matrix, ECM）은 조직 내 구조적 역할뿐만 아니라 면역 반응을 조절하는 능동적 인자로서 점차 주목받고 있다. ECM의 주요 구성 성분인 피브로넥틴（fibronectin, FN）은 염증 과정에서 동적인 변화를 겪으나, FN의 구조적 완전성（structural integrity）이 수지상세포（dendritic cell, DC） 활성화에 미치는 영향은 아직 충분히 밝혀지지 않았다. 본 연구에서는 염증 조건에서 intact FN과 FN 단편（FN fragment）이 골수유래 수지상세포（bone marrow-derived dendritic cell, BMDC）의 활성화에 미치는 영향을 조사하였다. Intact FN은 리포폴리사카라이드（lipopolysaccharide, LPS）에 의해 유도된 BMDC 활성화를 유의하게 억제하였으며, 이는 CD86 발현 감소와 종양괴사인자-α（tumor necrosis factor-alpha） 및 인터류킨-6（interleukin-6） 생산 감소를 통해 확인되었다. 반면, 염증세포에 의한 FN 분해 과정에서 관찰된 단편 크기를 바탕으로 선택한 시판 120-kDa FN 단편（FN-f）은 이러한 억제 효과를 유지하지 못하였다. 생체 내에서는 LPS 투여 후 비장에서 FN 염색 강도의 일시적인 변화가 관찰되었으며, 이는 DC 활성화 증가와 대식세포（macrophage, Mφ） 및 호중구（neutrophil）의 침윤과 동반되었다. 또한, LPS로 자극한 대식세포와 호중구의 배양상층액（conditioned media）은 시험관 내에서 FN 분해를 유도하였다. 염증세포, FN 함유 ECM 및 DC 활성화 간의 관계를 보다 생리학적으로 유사한 환경에서 평가하기 위하여 FN-콜라겐 겔 모델을 구축하였다. 이 모델에서 FN-콜라겐 겔이 나타내는 BMDC 활성화 억제 효과는 LPS 자극 조건에서 대식세포 또는 호중구가 존재할 경우 감소하였다. 종합적으로, 본 연구 결과는 FN의 수지상세포 활성화에 대한 면역조절 기능이 FN의 구조적 완전성에 의존함을 보여주며, 염증 과정에서 발생하는 FN의 구조적 변화가 ECM을 매개로 한 DC 활성화 조절에 영향을 미칠 수 있음을 시사한다.
more목차
I. INTRODUCTION 1
1. Overview of dendritic cells 1
2. Extracellular matrix and Fibronectin 4
3. Research gap and the aim of study 5
II. MATERIALS AND METHODS 7
1. Mice 7
2. Reagens and antibodies 7
3. Generation of BMDCs 8
4. In Vitro stimulation of BMDCs 10
5. Flow cytometry analysis 10
6. Enzyme-linked immunosorbent assay （ELISA） 11
7. LPS administration and murin spleen collection 11
8. Cryosection and immunohistochemistry （IHC） staining 11
9. Immunofluorescence （IF） staining 12
10. Isolation of peritoneal Mφ and neutrophils 12
11. Preparation of LPS-induced cell supernatants 13
12. Western blot 13
13. FN-collagen gel model 14
14. Cell staining with CellTracker 15
15. Immunocytochemistry staining 15
16. Harvesting BMDCs from FN-collagen gels 16
17. Statistical analysis 16
III. RESULTS 17
1. Fibronectin suppresses LPS-induced BMDC activation 17
2. Transient change in splenic FN staining following LPS administration 19
3. Changes in splenic immune cells following LPS administration 21
4. LPS-induced cell supernatants promote FN fragmentation in vitro 23
5. FN-f does not suppress LPS-induced BMDC activation 25
6. Establishment of an FN-collagen gel model to mimic inflammatory microenvironments 27
7. The spatial distribution of cells within the FN-collagen gel model 29
8. Mφ or neutrophils restore BMDC activation within FN-collagen gel under LPS stimulation 31
IV. DICUSSION 34
V. CONCLUSION 37
VI. REFERENCES 38
초록 40
