P0260 - Effects of Probiotic-Derived Extracellular Vesicles (EV) and NK Cells in Human Colorectal Cancer Cells

Dong Ho Lee, MD, PhD¹, Jung Hyun Kim, PhD², Ki Sung Kang, ², Jin-Sol Lee, MS², Na Ri Lim, ², Won Suk Lee, ², Young Soo Park, MD¹, Cheol Min Shin, MD¹, Hyuk Yoon, MD¹, Na Young Kim, MD¹, Eun Ji Lee, MD¹, Yu Jin Kim, MD¹, Mun Jin Ju, MD¹, Ye Ji Choi, MD^1
1Seoul National University Bundang Hospital, Seongnam, Kyonggi-do, Republic of Korea; ²BioBankHealing, Seongnam, Kyonggi-do, Republic of Korea

Introduction: Probiotics maintain the balance of the gut microbiome by regulating innate immunity. There were reports that it regulates proliferation, inflammation, and apoptosis in cancer cells. In particular, microbiota-derived extracellular vesicles (EV) play an important role in cell-to-cell communication through their ability to transport biologically active molecules (nucleic acids, proteins, lipids, metabolites). Natural killer (NK) cells also control several types of tumor and microbial infections as lymphocytes effectors of the innate immune system. Therefore, we expected to inhibit the activity of cancer cells by interacting with them through the regulation of the immune system. In this study, we co-cultured EV and NK cells in colorectal cancer cell lines to confirm their anti-inflammatory and anti-cancer effects.



Methods: The Peripheral Blood Mononuclear cells (PBMCs) were isolated from whole blood samples of 5 healthy donors after receiving informed consent. Subsequently, NK cells were purified and selected with one of the best conditions through FACS analysis. Bifidobacterium breve (B. breve) was cultured for 24 h under anaerobic conditions at 37 °C after isolated from feces of healthy humans. The antimicrobial activity of B. breve-derived EV against C. difficile was determined by evaluating C. difficile growth.

Results: B. breve-derived EV showed high antibacterial activity as induced low survival rates of C. difficile. We found that this B. breve affected NK cell activation by increasing human interferon-gamma (IFN-γ) production. In addition, the expression of cytokines and pro-apoptosis increased while expression of metastasis decreased in colorectal cancer cells line (Caco-2) by co-treatment of NK cells and B. breve-derived EV.

Discussion: Our studies suggest the possibility that B. breve-derived EV induces cancer cell death by synergistically influencing the killing ability of NK cells, and further research is in progress.




Disclosures:
Dong Ho Lee indicated no relevant financial relationships.
Jung Hyun Kim indicated no relevant financial relationships.
Ki Sung Kang indicated no relevant financial relationships.
Jin-Sol Lee indicated no relevant financial relationships.
Na Ri Lim indicated no relevant financial relationships.
Won Suk Lee indicated no relevant financial relationships.
Young Soo Park indicated no relevant financial relationships.
Cheol Min Shin indicated no relevant financial relationships.
Hyuk Yoon indicated no relevant financial relationships.
Na Young Kim indicated no relevant financial relationships.
Eun Ji Lee indicated no relevant financial relationships.
Yu Jin Kim indicated no relevant financial relationships.
Mun Jin Ju indicated no relevant financial relationships.
Ye Ji Choi indicated no relevant financial relationships.


Dong Ho Lee, MD, PhD¹, Jung Hyun Kim, PhD², Ki Sung Kang, ², Jin-Sol Lee, MS², Na Ri Lim, ², Won Suk Lee, ², Young Soo Park, MD¹, Cheol Min Shin, MD¹, Hyuk Yoon, MD¹, Na Young Kim, MD¹, Eun Ji Lee, MD¹, Yu Jin Kim, MD¹, Mun Jin Ju, MD¹, Ye Ji Choi, MD¹. P0260 - Effects of Probiotic-Derived Extracellular Vesicles (EV) and NK Cells in Human Colorectal Cancer Cells, ACG 2021 Annual Scientific Meeting Abstracts. Las Vegas, Nevada: American College of Gastroenterology.