isolation of mononuclear cells from whole blood to obtain induced microglia-like cells for brain research

인간의 뇌 질환을 연구하기 위한 혈액 유도 미세아교세포 유사 세포 개발

In recent years, brain inflammation has been suggested to assume pivotal roles in the pathophysiology of various brain and neuropsychiatric disorders; the microglia have been highlighted as key immunomodulatory cells by human postmortem brain analysis and positron emission tomography (PET)-based bio-imaging techniques1,2,3,4. Postmortem brain and PET imaging analyses reveal significant findings; nevertheless, however, these approaches are inefficient in terms of capturing the dynamic molecular activities of human microglia in the brain in their entirety. Therefore, novel strategies are required to enable the comprehensive evaluation of human microglial functions and dysfunctions at the molecular and cellular levels.
In 2014, we originally engineered a novel technique to produce directly induced microglia-like(iMG) cells5,6, prior to the first publication of human-induced pluripotent stem cell (iPSC)-derived microglia-like cells in 20167. In just 2 weeks, we successfully converted human peripheral blood monocytes into iMG cells by optimizing the cytokines, granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin 34 (IL-34). When we developed this technique, the innovative reprogramming method of inducing neuronal cells from iPS cells or fibroblasts was just beginning to prevail in the world8,9,10,11. However, at that time, a method for inducing iPS-derived microglial cells had not yet been reported, and the generation of a human somatic cell-derived microglial model was desired. Since cytokines such as GM-CSF and IL-34, macrophage colony-stimulating factor, were reported to be necessary for the development and maintenance of microglia12,13,14,15, we hypothesized that a combination of these cytokines could be applied directly to generate a microglial cellular model from blood monocytes. Finally, we succeeded in developing a model of microglia derived from monocytes by combining GM-CSF and IL-345. In addition, some of these combinations of cytokines are also employed to induce microglia from iPS cells7,16 and are assumed to be an important factor in acquiring microglial characteristics.
In contrast to iPSC methods, iMG cells do not require any genetic modification and can be generated in a very short time by simple chemical induction, resulting in lower time and financial costs. Furthermore, iMG cells do not require genetic reprogramming, so we believe that iMG cells are potent surrogate cells to evaluate not only the traits but also the states of human microglia. In the initial paper on the iMG technique in 2014, we confirmed that iMG cells exhibit a phenotype of human microglia, which can be distinct from monocytes and macrophages. For example, iMG cells exhibited an overexpression ratio of CX3C chemokine receptor 1 (CX3CR1) and C-C chemokine receptor type 2 (CCR2) than monocytes and typical microglia markers, including transmembrane protein 119(TMEM 119) and purinergic receptor P2RY125,17. Recently, we validated that peripheral blood-derived iMG cells resemble brain microglia in their gene expression profile of well-known microglial markers in the same patient who underwent brain surgeries18. The iMG cells can be analyzed for dynamic functions at the molecular level, such as phagocytosis and cytokine production, and are expected to compensate for the disadvantages of postmortem brain research and PET studies.
We have discovered previously unknown dynamic pathophysiological mechanisms involving microglia in patients diagnosed with Nasu-Hakola disease5, fibromyalgia19, bipolar disorder20,21, or Moyamoya disease22. Furthermore, based on our original methodology, various laboratories have employed the iMG cells (certain laboratories have designated alternative names to these cells) as a crucial reverse-translational research tool23,24,25,26,27. Sellgren et al. successfully generated iMG cells in compliance with our recommendations and conducted a microarray analysis, which revealed that these cells closely resemble human brain microglia23. Recently, we confirmed the resemblance between human iMG cells and brain primary microglia using RNA sequencing18.
This study aimed to document the methodology to generate iMG cells from human peripheral blood to facilitate reverse-translational research focused on neuropsychiatric diseases. This technique presents potential as a reasonable analytical tool that can effortlessly produce microglial cellular models in a brief duration, even in ill-equipped laboratories that lack gene transfer apparatus or proficient personnel.

저자 스포트라이트: 신경정신 질환에서 미세아교세포 기능 장애의 역할을 밝히기 위한 유도된 미세아교세포와 유사한 세포 기술

역번역 뇌 연구를 위한 인간 혈액 유도 미세아교세포 유사 세포 엔지니어링

Our lab at Kyushu University aimed to clarify the roles of microglial dysfunction in various neuropsychiatric disorders. We believe that our iMG cell technology will shed new light on microglial dynamic function and dysfunction at the cellular level in human beyond the limitation of human brain analysis, such as postmortem study and also pet brain studies. Even now, animal experiments are essential to clarify the brain pathophysiology of mental disorders, but it is unclear how well rodent data can be applied to human pathophysiology.Our human blood-induced iMG cell technology will this gap between rodent data, clinical data, and microglial function and/or dysfunction. Other human-derived cellular disease model, human iPS cell-derived microglia cells are also developed, which need much time and much money to develop and can assess trait markers but not state markers. The advantage of our iMG method is that it is much simpler, less time-consuming, and cost-effective.We have already revealed several candidate molecular factors by our reverse translational iMG research focusing on neuropsychiatric disorders such as dementia disease, bipolar disorder, fibromyalgia, glioma, and disease. We believe that our iMG cell technology will shed new light on microglial dynamic function and dysfunction at the cellular levels in various neuropsychiatric disorders.

뇌 연구를 위한 유도 미세아교세포(induced microglia-like cells)를 얻기 위해 전혈(whole blood)에서 단핵 세포를 분리합니다.

시작하기 위하여는, 15 밀리리터 원심분리 관에 있는 조밀도 구배 매체의 15 밀리리터를 끼워넣고 1, 20 섭씨 온도에 1 분 동안 000 G를 회전시킨다. 헤파린에 채취 된 인간의 혈액이 들어있는 튜브를 뒤집고 화재 멸균 핀셋을 사용하여 혈액 수집 튜브의 뚜껑을 제거합니다. 약 10-15 밀리리터의 혈액을 튜브의 밀도 구배 배지에 분배합니다.1개에 분리기의 감속 수준을 놓고 실내 온도에 10 분 동안 1, 000 G에 혈액을 가진 관을 분리한다. 버피 코트에서 최대 1cm 위까지 플라즈마의 최상층을 제거합니다. 원심분리 튜브의 나머지 상층액을 10ml의 PBS가 포함된 다른 원심분리기 튜브로 디캔팅합니다.원심분리기의 감속 수준을 3으로 재설정하고 PBS와 상등액으로 튜브를 원심분리합니다. 상층액을 흡입하고 튜브를 가볍게 두드려 펠릿을 풉니다. 다음으로, 13ml의 분리 매체를 원심분리기 튜브에 넣고 내벽을 세척하여 세포를 제대로 수집합니다.화재 멸균 핀셋을 사용하여 100밀리리터 원뿔형 튜브에 15마이크로미터 셀 스트레이너를 놓습니다. 그런 다음 셀 스트레이너를 통해 셀 현탁액을 15밀리리터 원추형 튜브로 여과합니다. 동일한 양의 세포 현탁액을 두 개의 15밀리리터 원뿔형 튜브에 분주합니다.격리 완충액의 적절한 농도를 계산하기 위해 셀을 열거합니다. 섭씨 4도에서 10분 동안 250G의 세포를 펠렛합니다. 상층액을 제거한 후 적당량의 분리 완충액과 피펫을 약 20회 추가하여 펠릿을 풉니다.

Research

JoVE Journal

Immunology and Infection

Isolation of Mononuclear Cells from Whole Blood to Obtain Induced Microglia-Like Cells for Brain Research

Developing Blood-Induced Microglia-Like Cells for Studying Human Brain Disorders

Engineering of Human Blood-Induced Microglia-like Cells for Reverse-Translational Brain Research

Author Spotlight: Induced Microglia-Like Cell Technology to Shed Light on the Role of Microglial Dysfunction in Neuropsychiatric Disorders

Recent investigations employing animal models have highlighted the significance of microglia as crucial immunological modulators in various ...

연구

면역학 및 감염병학

Obtaining Induced Microglia-Like Cells from Whole-Blood Derived Monocytes for Probing Microglial Dynamics in Human Diseases

인간 질병의 미세아교세포 역학을 조사하기 위해 전혈 유래 단핵구에서 유도된 미세아교세포 유사 세포 획득 