Immune Modulatory Effect of Outer Membrane Vesicles Derived from Salmonella on Mouse Bone Marrow-Derived Dendritic Cells
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摘要:目的 研究鼠伤寒沙门菌(Salmonellatyphimurium, ST)外膜囊泡(outer membrane vesicles, OMVs)对树突状细胞(dendritic cells, DC)超微结构及免疫功能的影响。方法 无菌取小鼠骨髓细胞,体外经重组鼠源粒细胞/巨噬细胞集落刺激因子(recombinant mouse granulocyte-macrophage colony-stimulating factor, rm GM-CSF)和重组鼠源白细胞介素-4(recombinant mouse interleukin-4, rm IL-4)联合诱导扩增出DC,倒置相差显微镜下观察细胞形态,流式细胞术鉴定表型;超速离心分离获取ST-OMVs,CCK-8法测其对DC存活情况的影响,确定OMVs刺激浓度;透射电镜观察细胞负载OMVs后超微结构特征;流式细胞术检测DC细胞因子分泌、表面分子表达、吞噬能力。结果 体外诱导和扩增的DC具有典型的细胞形态,纯度达85%以上,透射电镜可见DC表面有大量丝状伪足;OMVs负载后,可见DC表面树突状结构减少,胞浆内有大量囊泡状结构,线粒体增多,肿胀以及细胞凋亡;OMVs 5 μg/mL和10 μg/mL 处理后,DC吞噬能力下降(P<0.05),成熟表型特征性分子表达上调(P<0.05),肿瘤坏死因子-α(tumor necrosis factor-α, TNF-α)和白细胞介素-1β(interleukin-1β, IL-1β)表达升高(P<0.05)。结论 ST-OMVs可诱导DC分泌TNF-α和IL-1β,具有促进DC成熟和抗原提呈的能力。Abstract:Objective To study the effect of outer membrane vesicles (OMVs) derived from Salmonellatyphimurium (ST) on the ultrastructural features and immune function of dendritic cells (DC).Methods Mice bone marrow cells were collected aseptically, and myeloid DC were generated by the combined induction and amplification with recombinant mouse granulocyte-macrophage colony-stimulating factor (GM-CSF) and recombinant mouse interleukin-4 (rm IL-4). Cell morphology was observed under inverted phase contrast microscope and the phenotype was identified with flow cytometry. ST-OMVs were isolated through ultracentrifugation. The survival rate of DC was assessed with CCK-8 assay, and the stimulus concentration of OMVs was henceforth determined. The ultrastructural characteristics of DC loaded with OMVs were observed with transmission electron microscopy. The cytokine secretion, surface molecule expression and phagocytic capacity of DC were examined with flow cytometry.Results The DC induced and amplified in vitro displayed typical DC phenotype in morphological analysis and the purity of DC exceeded 85%. Transmission electron microscopy showed that there were large numbers of protrusions on the cell surface. After stimulation with ST-OMVs, it was observed that the dendritic structures on the surface of DC were reduced and a large number of phagolysosomes were found in the cytoplasm. In addition, increased numbers of mitochondria, swelling and typical apoptosis were observed. After treatment with ST-OMVs at 5 μg/mL and 10 μg/mL, the secretion of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) of DC increased significantly (P<0.05). Furthermore, the immature DC could differentiate into mature DCs after stimulation with ST-OMVs, which were characterized by a decrease in phagocytic capacity (P<0.05) and an upregulation of phenotypic markers (P<0.05).Conclusion ST-OMVs can stimulate DC to produce TNF-α and IL-1β and promote DC maturation and antigen presentation.
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Keywords:
- Salmonella typhimurium /
- Outer membrane vesicles /
- Dendritic cells
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细胞外囊泡是细胞释放的各种由膜包绕的囊泡样结构的统称,普遍存在于真核细胞及原核细胞中。细菌胞外囊泡首次是在大肠埃希菌中被发现[1],革兰阴性菌以出芽的方式分离出来的胞外囊泡通常被称为外膜囊泡(outer membrane vesicles, OMVs)。OMVs是原核细胞有目的产生的纳米结构[2],保留了亲本细菌的理化特性,含有功能特定的生物活性蛋白、核酸和代谢物等[3-4]。目前,OMVs的分泌已被认为是细胞间的通讯方式,细菌可通过这一方式进行营养摄取、基因转移以及应激应答[5]。OMVs也可与宿主细胞结合并将其中的生物活性物质运输到细胞内,影响受体细胞的生物活性[6]。
随着研究的不断深入,OMVs对宿主免疫系统的调控作用引起越来越多的关注。树突状细胞(dendritic cell, DC)是起源于骨髓的专职抗原提呈细胞(antigen-presenting cell, APC),处于启动、调控和维持免疫应答的中心环节。DC在沙门菌入侵部位存在,可吞噬细菌并具有向淋巴器官迁徙和刺激初始T淋巴细胞的能力,这些特性决定了它们在启动针对沙门菌感染的特异性免疫应答过程中发挥重要作用。本研究以鼠伤寒沙门菌(Salmonella typhimurium CMCC50115, ST)为对象,利用超速离心法提取ST-OMVs,通过检测其对DC超微结构及免疫功能的影响,探索细菌OMVs的生物学活性,以期为进一步研究ST致病性及机体免疫防御提供新思路。
1. 材料与方法
1.1 材料
1.1.1 菌株和实验动物
鼠伤寒沙门菌(CMCC50115)购于中国药品生物制品检定所(GMCC)。健康清洁级雄性C57BL/6(B6)小鼠,鼠龄8~10周,购自扬州大学动物实验中心,许可证号:SCXK苏2007-0001。
1.1.2 主要试剂和仪器
RPMI 1640干粉(美国Gibco公司);胎牛血清(fetal bovine serum, FBS;美国Hyclone公司);重组小鼠白细胞介素-4(recombinant mouse interleukin-4, rm IL-4)和粒细胞/巨噬细胞集落刺激因子(recombinant mouse granulocyte-macrophage colony-stimulating factor, rm GM-CSF)购自美国Peprotech公司;CD11c、CD54、CD86和MHC Ⅱ流式抗体及同型对照(美国eBioscience公司);细胞因子白细胞介素-1β(interleukin-1β, IL-1β)、肿瘤坏死因子-α(tumor necrosis factor α, TNF-α)检测试剂盒(美国Bender公司);其它试剂均为进口分装或国产分析纯;超速离心机(美国Beckman-Coulter公司);流式细胞仪FACS Calibur(美国BD公司);Leica EM UC 6超薄切片机(德国Leica Company公司);透射电子显微镜H-600 (日本Hitachi公司);CO2恒温培养箱(德国Heraeus公司);倒置显微镜(日本Olympus公司)。
1.2 实验方法
1.2.1 ST-OMVs的提取
细菌用LB液体培养基培养至OD600为1.0时,进行超速冷冻离心,4 ℃,15 000×g,20 min;离心后取上清经0.22 μm无菌滤膜过滤除菌,滤液于4 ℃条件下150 000×g,离心2 h,弃上清,沉淀即为提取的胞外囊泡。BCA法测蛋白浓度,调整至1 mg/mL,−80 ℃冰箱中保存备用。
1.2.2 小鼠骨髓源DC的制备及纯度鉴定
参照文献的方法[7]并加以改进,麻醉后颈椎脱臼法处死小鼠,自来水冲洗后置于体积分数75%乙醇内浸泡5 min,无菌状态下取小鼠股骨及胫骨,尽量完全去除表面的肌肉和结缔组织,浸泡在RPMI 1640培养基中。分别于骨两端剪去约2 mm,用1 mL注射器吸取RPMI 1640培养液刺入骨髓腔反复冲洗,直至骨变白,离心收集无菌培养皿中的骨髓细胞悬液,加入3 mL无菌Tris-NH4Cl悬浮细胞,室温静置5 min裂解红细胞,加入4 mL RPMI 1640培养液,混匀后,离心弃上清,用RPMI 1640培养液洗涤,收集沉淀的骨髓细胞。将小鼠骨髓细胞重悬于完全培养基(含10%胎牛血清的RPMI 1640),接种于6孔培养板中,每孔补充完全培养基至4 mL,加入细胞因子rm GM-CSF 20 ng/mL、rm IL-4 10 ng/mL。置于37 ℃、体积分数5% CO2孵箱中孵育48 h,轻轻吹打细胞后,弃悬浮细胞和细胞碎片。加入完全培养基及相同浓度的细胞因子,继续孵育至第5天。半量换液,尽量保留悬浮细胞,同时补足细胞因子,培养至第7天时,于倒置相差显微镜下观察悬浮细胞形态变化情况;用吸管轻轻吹打培养板收获半悬浮及疏松贴壁细胞,用抗鼠 CD11c-FITC染色后经流式细胞术鉴定DC纯度。
1.2.3 CCK8法测ST-OMVs对小鼠骨髓源DC存活率的影响
调整DC细胞密度至5×104mL-1,按200 μL/每孔加入96孔板培养过夜,分别于各孔中加入不同质量浓度(0、1、5、10、20、50 μg/mL)的ST-OMVs,置体积分数5% CO2中,37 ℃细胞培养箱培养24 h后,每孔加入10 μL CCK-8,轻轻混匀后继续培养3 h。在酶标免疫检测仪上以450 nm测定吸光度值(A450)。计算细胞存活率:细胞存活率(%)=〔(实验孔A450−空白孔A450)/(对照孔A450−空白孔A450)〕×100%。
1.2.4 超薄切片制备及透射电镜观察小鼠骨髓源DC超微结构
分别用ST-OMVs 5、10 μg/mL刺激12 h后收集细胞,将收获的小鼠骨髓源DC离心洗涤取沉淀,缓慢沿管壁加入新鲜的戊二醛液(质量分数2.5%)固定2 h,磷酸盐缓冲液漂洗,质量分数1%锇酸固定1 h,梯度丙酮脱水,环氧树脂包埋,莱卡EM UC6超薄切片机切片,经醋酸铀-柠檬酸铅染色,采用日立H600型透射电镜观察摄片。
1.2.5 小鼠骨髓源DC吞噬功能检测
分别用ST-OMVs 5、10 μg/mL刺激骨髓源DC,同时设未刺激组阴性对照,作用24 h后加入终质量浓度1 mg/mL FITC-dextran,体积分数5% CO2、37 ℃孵育30 min。台盼蓝处理3 min淬灭细胞表面黏附的荧光颗粒,用预冷的PBS(含0.1% NaN3和1% FBS)洗涤,应用流式细胞术检测,以DC的阳性荧光细胞数与实验体系中所有细胞的比值表征DC的吞噬率。Cellquest软件分析检测结果。
1.2.6 ELISA法检测小鼠骨髓源DC细胞因子
通过测定OMVs刺激后促炎性细胞因子(TNF-α、IL-1β)评定骨髓源DC对ST-OMVs的应答反应。分别用ST-OMVs 5、10 μg/mL刺激骨髓源DC,同时设未刺激组阴性对照,刺激后24 h收集细胞培养液上清,于−80 ℃冰箱储存,ELISA检测试剂盒测定细胞因子IL-1β和TNF-α的释放水平,步骤参照试剂盒说明书。
1.2.7 小鼠骨髓源DC表型检测
分别用ST-OMVs 5、10 μg/mL刺激骨髓源DC,同时设未刺激组阴性对照,刺激后24 h收集小鼠骨髓源DC,分别加入PE anti-CD86、MHC Ⅱ或CD54单抗,于4 ℃避光孵育30 min,洗涤后流式细胞仪检测并分析结果。
1.3 统计学方法
计量资料用
$ \bar x \pm s $ 表示。采用单因素方差分析和q检验进行组间比较,P<0.05为差异有统计学意义。2. 结果
2.1 小鼠骨髓源DC形态学观察及纯度鉴定
小鼠骨髓细胞培养48 h后,弃未贴壁细胞及细胞碎片,可见形状不规则的半贴壁细胞,呈梭形,有细胞聚集现象,但集落较小(图1A);第5天可见部分细胞脱壁,细胞数渐增,集落逐渐变大,形状也趋典型,即细胞表面出现放射状突起改变,在相差显微镜下其形态见图1B;培养至第7天,可见较大体积的悬浮细胞,向四周伸展出大量毛刺状胞质凸起,呈“刺猬状”,贴壁时有细长凸起,呈“树突状”(图1C)。离心收集细胞样本经流式细胞仪检测分析,扩增到的细胞中CD11c阳性的小鼠骨髓源DC纯度达到85%以上(图1D)。
图 1 小鼠骨髓源DC形态及纯度分析Figure 1. Morphology and purity analysis of DCA: The cells gathered and formed tiny colonies (as shown by the arrow) (×400); B: Cell colonies became larger (as shown by the arrows) (×400); C: The suspension cell colonies extended a large number of radial protrusions (as shown by the arrows) (×400); D: Purity analysis of DC.2.2 ST-OMVs对小鼠骨髓源DC存活率的影响
见图2。低质量浓度ST-OMVs(1 、5 、10 μg/mL)对小鼠骨髓源DC存活率影响小(P>0.05)。当ST-OMVs质量浓度≥20 μg/mL,DC的存活率降低(P<0.05),ST-OMVs质量浓度为50 μg/mL时,小鼠骨髓源DC的存活率仅为54.9%,呈现明显的细胞毒作用。因此在本研究后续实验中,选择ST-OMVs 5 μg/mL和10 μg/mL作为刺激浓度。
2.3 小鼠骨髓源DC超微结构观察
透射电镜观察发现未刺激小鼠骨髓源DC表面大量突起呈触须状,胞质均匀,少量高密度颗粒,核偏在,核膜清晰(图3A)。5 μg/mL ST-OMVs刺激后,骨髓源DC出现体积变大,表面树突样结构减少,胞内细胞器丰富等改变。图中所示为10 μg/mL ST-OMVs负载后,胞浆内出现大量大小不等的囊泡状结构(图3B),线粒体增多,体积增大,胞核浓缩,染色质边缘化聚集于核膜及凋亡小体形成等典型的凋亡改变(图3C)。细胞培养过程中,有些细胞在培养液中死亡,骨髓源DC吞噬、消化坏死的细胞碎片后,胞内出现明显的髓鞘样结构(一圈一圈的同心圆)(图3D)。
图 3 吞噬前后小鼠骨髓源DC的超微结构Figure 3. Ultrastructural characteristics of DC during phagocytosisA: Unstimulated DC (×4 000); B: The number of synapses on DC decreased, and the organelles in the cytoplasm, such as lysosomes (as shown by the white arrows) and mitochondria (as shown by the black arrows), were abundant (×5 000); C: Swollen mitochondria (as shown by the arrows) (×5 000); D: Myelin-like structures in cells (as shown by the arrow) (×7 000).2.4 ST-OMVs对小鼠骨髓源DC吞噬功能的影响
未经刺激的骨髓源DC具有很强的吞噬能力,FITC-dextran阳性细胞比率为(78.9±7.3)%,5 μg/mL和10 μg/mLST-OMVs作用组骨髓源DC吞噬率分别为(52.6±4.5)%和(34.9±4.2)%,较对照组低(P<0.05)。
2.5 ST-OMVs对小鼠骨髓源DC细胞因子分泌的影响
由图4可见,与对照组相比,5 μg/mL和10 μg/mL ST-OMVs处理组炎症因子TNF-α和IL-1β表达升高(P<0.05),但不同质量浓度组间IL-1β含量差异无统计学意义(P>0.05)。
2.6 小鼠骨髓源DC表型检测
由图5可见,5 μg/mL和10 μg/mL ST-OMVs刺激24 h后,小鼠骨髓源DC表面CD54、CD86和MHC Ⅱ分子阳性百分率上调(P<0.05),获得成熟表型。10 μg/mL ST-OMVs处理组小鼠骨髓源DC表面CD54、CD86和MHC Ⅱ分子阳性百分率均高于5 μg/mL ST-OMVs处理组(P<0.05)。
3. 讨论
大量研究表明,OMVs不是细菌受损或裂解的产物,而是菌细胞程序性产生的膜泡结构,可作为媒介在细菌和宿主之间传递生物信息,发挥类似于真核生物外泌体的功能[8]。作为一个异质的、富含蛋白和脂类的分子载体,OMVs可以看作是一种病原体相关分子模式(pathogen-associated molecular patterns, PAMP)复合物[9],通过与宿主细胞模式识别受体(pattern recognition receptor, PRR)结合启动信号级联反应,触发机体抗感染免疫。
DC作为机体免疫应答的始动者,能够识别并结合微生物抗原,完成抗原呈递,启动免疫应答,从而实现机体免疫防御。这一过程涉及一系列复杂的分子活动,任何对DC功能的影响都可能改变感染结局[10-11]。研究病原体成分和DC之间的相互作用,对于深入阐述病原微生物致病机制及宿主免疫机制具有重要意义。本研究联合应用rm GM-CSF和rm IL-4对小鼠骨髓细胞进行诱导和扩增,可获得大量纯度较高的髓系DC,每只小鼠平均可获得1×107~3×107细胞数。在倒置显微镜下可见培养液中大量呈悬浮状态的细胞具有典型的DC形态特点。DC前体细胞发育成熟过程中的一个很重要的特点是形成细胞集落。我们观察到在GM-CSF的刺激下,于培养第3天便出现由数个细胞形成的小集落[12],以后逐渐增大,形成顶部大、基部小的细胞集落,集落中有较典型的DC,体积大,表面毛刺状。电镜观察可见DC表面大量突起和分支相互缠绕,这一结构特征与DC强大的抗原捕获能力相一致。
在探究OMVs对DC超微结构影响的实验中,我们发现负载ST-OMVs后DC体积变大,表面树突样结构减少,胞内含有大量溶酶体和内体小泡,部分细胞出现线粒体增多、肿胀及凋亡等改变。FOSSATI-JIMACK等[13]研究表明,细胞被诱导凋亡后,磷脂酰丝氨酸和内质网肌钙蛋白暴露于表面,可作为识别配体与DC表面的CD11b分子结合,从而诱发DC对凋亡细胞的吞噬过程。本研究电镜下观察到的胞内盘旋缠绕的膜样结构,就是DC吞噬细胞碎片后膜性成分消化不全或磷脂类物质未能完全分解所致。经ST-OMVs诱导凋亡的细胞可作为细菌抗原的贮存库,被旁观DC抗原提呈。虽然目前针对DC加工、处理凋亡及坏死细胞的研究并不充分,但可以肯定的是这一过程为诱导免疫系统产生特异性的免疫应答提供了另外一种方式。
DC的活化过程与抗原获取密切相关,是一个高度复杂并受到严格调控的过程[14-15]。感染发生时,DC摄取加工抗原,上调包括趋化因子受体(如CCR7)、黏附分子、共刺激分子(CD54、CD80和CD86)、免疫蛋白体等分子的表达,释放大量炎性因子,激发免疫应答。本研究发现,负载ST-OMVs后DC分泌产生TNF-α和IL-1β增多,这一阶段DC自分泌和旁分泌产生的TNF-α和IL-1β主要调控DC在体内的成熟和迁移[16]。同时,ST-OMVs刺激后DC表面CD54、CD86和MHC Ⅱ类分子表达量均显著升高,但吞噬能力下降。实验结果显示暴露于ST-OMVs时,作为专职抗原提呈的细胞DC能够识别OMVs抗原,并经历一系列表型和功能改变,从而促进天然免疫和获得性免疫的有效联结。
综上,本研究优化了体外扩增DC的方法,对ST-OMVs的生物活性进行了探索,为厘清病原体成分与DC相互作用的细胞生物学基础提供更多线索。近年来,对于OMVs的组分分析、免疫调节以及早期诊断等研究不断深入,但针对其生物起源、调节基因及与宿主相互作用机制的研究尚不充分。在下一步研究中,我们将进一步探讨ST-OMVs产生机制及其相关特性,期待能为疾病的治疗及预防提供新思路。
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图 1 小鼠骨髓源DC形态及纯度分析
Figure 1. Morphology and purity analysis of DC
A: The cells gathered and formed tiny colonies (as shown by the arrow) (×400); B: Cell colonies became larger (as shown by the arrows) (×400); C: The suspension cell colonies extended a large number of radial protrusions (as shown by the arrows) (×400); D: Purity analysis of DC.
图 3 吞噬前后小鼠骨髓源DC的超微结构
Figure 3. Ultrastructural characteristics of DC during phagocytosis
A: Unstimulated DC (×4 000); B: The number of synapses on DC decreased, and the organelles in the cytoplasm, such as lysosomes (as shown by the white arrows) and mitochondria (as shown by the black arrows), were abundant (×5 000); C: Swollen mitochondria (as shown by the arrows) (×5 000); D: Myelin-like structures in cells (as shown by the arrow) (×7 000).
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[1] BISHOP D G, WORK E. An extracellular glycolipid produced by Escherichia coligrown under lysine-limiting conditions. Biochem J,1965,96(2): 567–576. DOI: 10.1042/bj0960567
[2] DREYER F, BAUR A. Biogenesis and functions of exosomes and extracellular vesicles. Methods Mol Biol,2016,1448: 201–216. DOI: 10.1007/978-1-4939-3753-0_15
[3] HASHIMOTO M, MATSUMOTO T, TAMURA-NAKANO M, et al. Characterization of outer membrane vesicles of Acetobacter pasteurianusNBRC3283. J Biosci Bioeng,2018,125(4): 425–431. DOI: 10.1016/j.jbiosc.2017.11.006
[4] FULSUNDAR S, KULKARNI H M, JAGANNADHAM M V, et al. Molecular characterization of outer membrane vesicles released from Acinetobacter radioresistens and their potential roles in pathogenesis. Microb Pathog,2015,83(84): 12–22. DOI: 10.1016/j.micpath.2015.04.005
[5] VANAJA S K, RUSSO A J, BEHL B, et al. Bacterial outer membrane vesicles mediate cytosolic localization of LPS and Caspase-11 activation. Cell,2016,165(5): 1106–1119. DOI: 10.1016/j.cell.2016.04.015
[6] ZINGL F G, KOHL P, CAKAR F, et al. Outer membrane vesiculation facilitates surface exchange andin vivo adaptation of vibrio cholerae. Cell Host Microbe,2020,27(2): 225–237. DOI: 10.1016/j.chom.2019.12.002
[7] INABA K, INABA M, ROMANI N, et al. Generation of large numbers of dendritic cells from mouse bone marrow cultures supplemented with granulocyte/macrophage colony stimulating factor. J Exp Med,1992,176(6): 1693–1702. DOI: 10.1084/jem.176.6.1693
[8] SEO N, SHIRAKURA Y, TAHARA Y, et al. Activated CD8+T cell extracellular vesicles prevent tumour progression by targeting of lesional mesenchymal cells. Nat Commun,2018,9: 435[2021-02-01]. https://doi.org/10.1038/s41467-018-02865-1.
[9] LI M, ZHOU H, YANG C, et al. Bacterial outer membrane vesicles as a platform for biomedical applications: an update. J Control Release,2020,323: 253–268. DOI: 10.1016/j.jconrel.2020.04.031
[10] EVANS H M, SIMPSON A, SHEN S, et al. The trophic life cycle stage of the opportunistic fungal pathogen pneumocystis murina hinders the ability of dendritic cells to stimulate CD4+ T cell responses. Infect Immun,2017,85(10): e00396–e00417[2021-02-01]. https://doi.org/10.1128/IAI.00396-17.
[11] BERENDS E T M, ZHENG X, ZWACK E E, et al. Staphylococcus aureus impairs the function of and kills human dendritic cells via the LukAB toxin. mBio,2019,10(1): e01918-18[2021-02-01]. https://doi.org/10.1128/mBio.01918-18.
[12] DONG Y, ARIF A A, POON G F, et al. Generation and identification of GM-CSF derived alveolar-like macrophages and dendritic cells from mouse bone marrow. J Vis Exp,2016,112: e54194[2021-02-01]. https://doi.org/10.3791/54194.
[13] FOSSATI-JIMACK L, LING G S, CORTINI A, et al. Phagocytosis is the main CR3-mediated function affected by the lupus-associated variant of CD11b in human myeloid cells. PLoS One,2013,8(2): e57082[2021-02-01]. https://doi.org/10.1371/journal.pone.0057082.
[14] YU KIMATA M T, CELLA M, BIGGINS J E, et al. Capture and transfer of simian immunodeficiency virus by macaque dendritic cells is enhanced by DC-SIGN. J Virol,2002,76(23): 11827–11836. DOI: 10.1128/JVI.76.23.11827-11836.2002
[15] RAPPOCCIOLO G, JAIS M, PIAZZA P A, et al. Human herpesvirus 8 infects and replicates in langerhans cells and interstitial dermal dendritic cells and impairs their function. J Virol,2017,91(20): e00909-17[2021-02-01]. https://doi.org/10.1128/JVI.00909-17.
[16] WICK M J. Monocyte and dendritic cell recruitment and activation during oral Salmonella infection. Immunol Lett,2007,112(2): 68–74. DOI: 10.1016/j.imlet.2007.07.007
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