对白细胞从流程的分析招聘基质细胞的影响

Summary

发炎的内皮从流动招募白细胞的能力是由间充质基质细胞调节。我们描述两个体外结合原代人细胞，它可以用于从流动评估中性粒细胞募集和检查的作用是间充质基质细胞在调节这个过程中发挥的模型。

Abstract

基质细胞调节通过与邻近血管内皮细胞的串扰炎症时白细胞流传的招聘。在这里，我们介绍两个体外 “血管”模型研究了发炎的内皮细胞流动循环中性粒细胞的招募。这些模型的一个主要优点是分析中的白细胞粘附级联的每个步骤，以便，如将发生在体内的能力。我们还描述了这两种模式如何可以适于研究的基质细胞的作用，在这种情况下，间充质干细胞（MSC），在调节白细胞募集。

初级内皮细胞单独或一起进行培养与人类的MSC在Ibidi microslides或在Transwell滤膜24小时的相对侧直接接触。培养物刺激肿瘤坏死因子（TNFα）4小时，掺入基于流的粘附试验。嗜中性粒细胞的丸灌注在内皮4分钟。嗜中性粒细胞流入和它们与内皮相互作用的捕获是可视化通过相衬显微镜。

在这两种模式，细胞因子刺激增加流动中性粒细胞内皮招聘呈剂量依赖性。招募嗜中性粒细胞的行为的分析表明剂量依赖性减少轧制和通过内皮的剂量依赖性增加轮回。在共培养，MSC抑制中性粒细胞粘附到TNFα刺激的内皮细胞。

我们基于流的粘连模型模拟白细胞招聘的初始阶段的循环。除了白细胞，它们可以被用来检查其它类型的细胞，如治疗给药的MSC或循环肿瘤细胞的募集。我们的多层共培养模型已经表明，MSC与内皮通信以修改其响应于促炎细胞因子，alteri纳克中性粒细胞的招募。采用这种模式需要进一步研究，充分了解来自不同组织和条件（炎症性疾病或癌症）如何基质细胞在炎症过程中影响白细胞的招募。

Introduction

炎症是对微生物感染或组织损伤的保护性反应，需要白细胞条目的紧调节进入和退出从发炎组织，以允许第^1,2。内皮细胞（EC），该行的血管，循环白细胞和组织驻留基质细胞之间的串扰是用于协调该过程³是必不可少的。然而，白细胞不受控制招聘和他们的无效间隙支撑的慢性炎症性疾病⁴的开发。我们目前在健康和疾病白细胞募集的理解是不完整的，还需要更可靠的模型来分析该过程。

通过血管EC的毛细血管后静脉支持从血液内白血球的招聘机制已经很好地描述^1,2,5。循环白细胞是通过专门的受体（ 例如，VCAM-1，E-选择素，P-选择素）捕获该正在上调对发炎内皮。这些短暂的相互作用使白细胞与表面结合趋化因子和脂质衍生的介质（或内皮细胞间质或起源）的激活白细胞^{6 11}表达整合互动。这反过来又稳定穿过内皮和进入组织^{12- 15}粘附和驱动器迁移。在组织，招募白细胞受到影响他们的运动，功能和存活^16,17基质衍生剂。越来越多的证据有力地表明，信号在招聘过程中条件的白细胞在接下来的每个阶段获得。然而，我们的白细胞招聘的认识仍然不完整，很少有人知道组织内的组件整形白细胞的运动。

在伯明翰，我们已经开发出多种体外 “血管”的车型，从研究白细胞招聘流^9,18,19。我们现在明白了，白细胞募集血管EC充当即时监管响应变化的局部微环境。具体地，组织驻留基质细胞可以通过与邻近血管EC交谈来影响在招募³的作用积极调节炎症反应，这部分。我们以前曾表明，各种基质细胞调制EC中以支持粘附和白细胞的迁移以组织特异性方式的能力，而且，这些效果变得改变在慢性疾病^{13,16,20,21。}因此，基质细胞建立组织'地址代码'定义每个炎性应答²²的上下文中。最近，我们已经表明，骨髓来源的MSC（BMMSC）有力地下调欧盟的细胞因子的反应，导致减少在这两个中性粒细胞的招募和淋巴细胞^23。

该机制GOVerning招聘阐明在体外已大量使用纳入一个单一的细胞类型（ 例如，EC）或蛋白质隔离检测。然而，这些研究并没有考虑到局部组织环境的影响（ 即，基质细胞的存在下）对招募白细胞及其随后迁移进入组织。在这里，我们描述了两个基于流的方法，其中的基质细胞，特异性间质干细胞（MSC），是共培养EC ^23。这种模型允许我们检查基质细胞对内皮反应的影响，特别是它们从流支持白细胞募集的能力。

Protocol

1.隔离初级人内皮细胞和间充质干细胞的培养和分离和培养人脐静脉内皮细胞（HUVEC）： 放脐带上用纸巾托盘和喷雾用70％的乙醇。放置在组织培养罩。识别静脉导管插入并在两端。周围放置的空心端部的电缆扎带将其固定。 洗出静脉血使用PBS中的注射器。填充注射器与空气和通过静脉拆除和丢弃残留的PBS。 解冻10毫克/毫升胶原酶IA和稀释在PBS中1:10的（钙和氯化镁），…

Representative Results

最初，我们分析了在使用Ibidi的MicroSlide模型（ 第7 – 9）从流嗜中性粒细胞的募集刺激EC与TNFα的影响。在不存在TNFα，如果小任何中性白细胞粘附到内皮细胞单层（ 图2A）的。这是意料之中的，因为未处理的/休息EC不表达必需的粘附分子（选择素）或趋化因子，以支持结合25,26。与此相反，细胞因子的刺激显著增加中性粒细胞粘附到内皮细胞中以剂量依赖的方式（ <…

Discussion

在这里，我们介绍两个体外 “血管”的模型来研究由内皮细胞发炎循环中性粒细胞的招募。这些模型的一个主要优点是分析中的白细胞粘附级联的每个步骤，以便，如将发生在体内的能力。我们先前观察到的剂量依赖性增加中性粒细胞粘附和轮回通过TNFα刺激的EC ^9,29。我们还描述了这两种模式如何适应学习基质细胞对白细胞招聘的影响。这里，MSC共培养用乳油在Ibidi的MicroSli…

Materials

Collagenase Type Ia	Sigma	C2674	Dilute in 10ml PBS to get a final concentration of 10mg/ml. Store at -20°C in 1ml aliquots.
Dulbecco's PBS	Sigma	D8662	With calcium and magnesium chloride. Keep sterile and store at room temperature.
1X Medium M199	Gibco	31150-022	Warm in 37 °C water bath before use.
Gentamicin sulphate	Sigma	G1397	Store at 4°C. Add to M199 500ml bottle.
Human epidermal growth factor	Sigma	E9644	Store at -20°C in 10µl aliquots.
Fetal calf serum (FCS)	Sigma	F9665	FCS must be batch tested to ensure the growth and viability of isolated EC. Heat inactivate at 56°C. Store in 10ml aliquots at -20°C.
Amphotericin B	Gibco	15290-026	Potent and becomes toxic within a week so fresh complete HUVEC medium must be made up every week. Store at -20°C in 1ml aliquots.
Hydrocortisone	Sigma	H0135	Stock is in ethanol. Store at -20°C in 10µl aliquots.
Collagenase Type II	Sigma	C6885	Dilute stock in PBS to a final concentration of 100mg/ml. Store at -20°C in 100µl aliquots.
Hyaluronidase	Sigma	H3631	Dilute stock in PBS to a final concentration of 20,000U/ml. Store at -20°C in 100µl aliquots.
100µm cell strainer for 50ml centifuge tube	Scientific Lab Supplies (SLS)	352360	Other commercially available cell strainers (e.g. Greiner bio-one) can also be used.
DMEM low glucose	Biosera	LM-D1102/500	Warm in 37 °C water bath before use.
Penicillin/Streptomycin mix	Sigma	P4333	Store at -20°C in 1ml aliquots.
25cm2 tissue culture flask	SLS	353109
75cm2 tissue culture flask	SLS	353136
Bone marrow mesenchymal stem cells vial	Lonza	PT-2501	Store in liquid nitrogen upon arrival. Cells are at passage 2 upon arrival but are designated passage 0. Exapand to passage 3 and store in liquid nitrogen for later use.
Mesenchymal stem cell growth medium (MSCGM)	Lonza	PT-3001	Warm in 37 °C water bath before use. For Cell Tracker Green staining use medium without FCS.
EDTA (0.02%) solution	Sigma	E8008	Store at 4°C. Warm in 37°C water bath before use.
Trypsin solution	Sigma	T4424	Store at -20°C in 2ml aliquots. Thaw at room temperature and use immediately.
Cryovials	Greiner bio-one	2019-02	Keep on ice before adding before adding cell suspension.
Mr. Frosty Freezing Container	Nalgene	5100-0001	Store at room temperature. When adding cryovials with cells store at -80°C for 24h before transfrring cells to liquid nitrogen.
Ibidi u-Slide VI (0.4), T/C treated, sterile	Ibidi	IB-80606	Alternative models include glass capillaries, Cellix Biochips (www.cellixltd.com), BioFlux Plates (www.fluxionbio.com/bioflux/) and GlycoTech parallel plate flow chambers (http://www.glycotech.com/apparatus/parallel.html).
Cell tracker green dye	Life technologies	C2925	Store in 5µl aliquots at -20°C. Dilute in 5ml prewarmed (at 37°C) MSCGM.
Cell counting chambers	Nexcelom	SD-100	Alternatively a haemocytometer can be used.
Cellometer auto T4 cell counter	Nexcelom	Auto T4-203-0238
Tumor necrosis factor α (TNFα)	R&D Systems	210-TA-100	Dilute stock in PBS to a final concentration of 100,000U/ml. Store at -80°C in 10µl aliquots.
6-well, 0.4µm PET Transwell filters	SLS	353090
K2-EDTA in 10ml tubes	Sarstedt		Store at room temperature.
Histopaque 1119	Sigma	11191	Store at 4°C. Warm to room temperature before use.
Histopaque 1077	Sigma	10771	Store at 4°C. Warm to room temperature before use.
10ml round bottomed tube	Appleton Woods	SC211 142 AS
7.5% BSA Fraction V solution	Life technologies	15260-037	Store at 4°C.
20ml Plastipak syringes	BD falcon	300613
5ml Plastipak syringes	BD falcon	302187
2ml Plastipak syringes	BD falcon	300185
3M hypo-allergenic surgical tape 9m x 2.5cm	Micropore	1530-1	Use to secure the syringe tap onto the wall of the perspex chamber.
Silicon rubber tubing, internal diameter/external diameter (ID/OD) of 1/3mm (thin tubing)	Fisher Scientific	FB68854	Cut silicon tubing to the appropriate size. All tubing leading directly to the electronic microvalve must be thin.
Silicon rubber tubing ID/OD of 2/4mm (thick tubing)	Fisher Scientific	FB68855
Portex Blue Line Manometer tubing	Smiths	200/495/200	Tubing leading to the syringe pump.
3-way stopcock	BOC Ohmeda AB
Glass 50ml syringe for pump	Popper Micromate	550962	Must be primed prior to use by removing any air bubbles.
Glass coverslip	Raymond A Lamb		26x76mm coverslips made to order. Lot number 2440980.
Parafilm gasket	American National Can Company		Cut a 26x76mm piece of parafilm using an aluminium template and cut a 20x4mm slot into it using a scalpel 10a. Gasket thickness is approximately 133µm.
Two perspex parallel plates	Wolfson Applied Technology Laboratory		Specially designed chamber consisting of parallel plates held together by 8 screws. The lower plate has a viewing slot cut out in the middle and a shallow recess milled to allow space for the coverslip, filter and gasket. The upper perspex plate has an inlet and outlet hole positioned over the flow channel.
Electronic 3-way microvalve with min. dead space	Lee Products Ltd.	LFYA1226032H	Electronically connected to a 12 volt DC power supply.
Syringe pump for infusion/withdrawal (PHD2000)	Harvard Apparatus	70-2001	Set the diameter to 29mm and refill (flow) rate.
L-shaped connector	Labhut	LE876	To attach to the inlet and outlet ports onto the Ibidi microslide channel.
Video camera	Qimaging	01-QIC-F-M-12-C	Connected to a computer which enables digitall videos to be recorded.
Image-Pro Plus 7.0	Media Cybernetics	41N70000-61592	For data analysis. Manually tag cells displaying the different behaviors. Track cells for analysis of rolling and migration velocities.
			Refer to product datasheets for details on hazards of using the reagents described here.