NGF 及其受体TrkA 在子宫腺肌病中的表达及与痛经的关系

目的:研究NGF及其受体TrkA在子宫腺肌病患者的异位内膜与在位内膜组织的表达情况及与痛经的关系。方法:采用免疫组化MaxVision法检测子宫腺肌病异位内膜(30例)、在位内膜(30例)、正常子宫内膜(19例)标本中NGF、TrkA蛋白的表达,分析其表达差异及与痛经的关系。结果:①子宫腺肌病异位内膜组NGF、TrkA表达显著高于正常内膜组(P<0.01),在位内膜组NGF、TrkA表达显著高于正常内膜组(P<0.01),子宫腺肌病异位内膜组NGF、TrkA表达与在位内膜组无显著差异。②子宫腺肌病异位内膜组NGF、TrkA表达与痛经强度评分呈正相关(相关系数r=0.637,P=0.000;r=0.662,P=0.000)。结论:NGF及其受体TrkA在子宫腺肌病中高表达可能参与子宫腺肌病发病机制,而且可能与痛经有关。     

Survivin和MMP-9在子宫上皮和间质细胞中的表达与子宫内膜异位症间的关系

目的研究Survivin蛋白和基质金属蛋白酶9（matrix metalloproteinase-9,MMP-9）在子宫腺肌症（ade-nomyosis,AM）、腹壁子宫内膜异位症（abdominal wall endometriosis,AWEMS）、卵巢子宫内膜异位症（ovary endometri-osis,OEMS）的在位、异位内膜的腺上皮细胞和间质细胞中的表达,并与对照组进行比较,探讨其在子宫内膜异位症（endometriosis,EMS）的发生发展中的作用。方法采用免疫组化法检测各组织标本中Survivin和MMP-9的表达。结果 （1）在正常子宫内膜组织中Survivin、MMP-9均呈弱表达或无表达。在EMS三个病例组中,无论是在位内膜还是异位内膜组织Survivin、MMP-9的表达均有不同程度的上调,分别与正常子宫内膜组织表达比较差异有统计学意义（P〈0.05）。（2）在AM、AWEMS、OEMS三个病例组中,仅在增生期异位内膜腺上皮细胞和间质细胞中Sur-vivin、MMP-9的表达分别高于在位内膜同类细胞的表达,差异均有统计学意义（P〈0.05）;分泌期则呈不规律表达。（3）在AM、AWEMS、OEMS三个病例组中,限定相同组织部位、相同细胞类型,增生期与分泌期Survivin、MMP-9的表达水平差异无统计学意义（P〉0.05）且无周期性。（4）在AM、AWEMS、OEMS三个病例组中,限定相同生理期、相同组织部位比较腺上皮细胞与间质细胞Survivin、MMP-9的表达：腺上皮细胞显著高于间质细胞的表达,差异有统计学意义（P〈0.05）。（5）EMS三个病例组之间,限定相同生理期、相同组织部位、相同细胞类型,组间分别比较Survivin或MMP-9的表达水平：Survivin表达差异无统计学意义（P〉0.05）,异位内膜仅分泌期MMP-9在AWEMS腺上皮细胞的表达（4.45±0.18）和AM腺上皮细胞的表达（4.68±0.17）高于OEMS异位内膜腺上皮细胞的表达（2.13±0.12）,差异均有统计学意义（P〈0.05）。结论 Survivin和MMP-9在EMS在位内膜和异位内膜腺上皮细胞和间质细胞中高表达可能是内异症发生发展的重要因素并有协同作用,在位内膜异常是EMS发病的决定性因素,腺上皮细胞高表达在EMS的发生发展中起主导作用,AM、AWEMS、OEMS三个病例组中的生物学特性不同可能受发病诱因、腹腔内环境及多种相关因子影响。     

神经细胞黏附因子在子宫腺肌病病灶中的表达及意义

目的:探究神经细胞黏附因子(NCAM)在子宫腺肌病病灶中的表达及意义。方法:将2016年6月~2017年6月在我院接受治疗的80例子宫腺肌病患者作为研究对象,包括分泌期与增生期各40例,采用免疫组化法检测,其在位内膜、异位内膜组织中NCAM表达情况,并以同期我院40例正常者子宫内膜标本作为对照。对子宫腺肌病患者痛经程度给予NRS疼痛评估,比较其NCAM的表达。结果:80例子宫腺肌病在位内膜、异位内膜均存在NCAM表达,40例正常内膜腺上皮有38例存在NCAM表达,2例正常内膜无表达。NCAM在异位内膜组织中的表达明显高于在位内膜及正常子宫内膜(P0.05),差异均有统计学意义。NCAM在在位内膜组织分泌期表达与增生期差异有统计学意义(P0.05);子宫腺肌病异位病灶NCAM表达与患者NRS评分呈现明显正相关(r=0.824,P0.05)。结论:NCAM在异位子宫内膜高表达,可能参与了子宫内膜异位症的发生和发展,并与患者痛经程度呈现出正相关。     

NGF及其受体TrkA在子宫腺肌病中的表达及与痛经的关系

目的：研究NGF及其受体TrkA在子宫腺肌病患者的异位内膜与在位内膜组织的表达情况及与痛经的关系。方法：采用免疫组化MaxVision法检测子宫腺肌病异位内膜（30例）、在位内膜（30例）、正常子宫内膜（19例）标本中NGF、TrkA蛋白的表达,分析其表达差异及与痛经的关系。结果：①子宫腺肌病异位内膜组NGF、TrkA表达显著高于正常内膜组（P〈0.01）,在位内膜组NGF、TrkA表达显著高于正常内膜组（P〈0.01）,子宫腺肌病异位内膜组NGF、TrkA表达与在位内膜组无显著差异。②子宫腺肌病异位内膜组NGF、TrkA表达与痛经强度评分呈正相关（相关系数r=0.637,P=0.000;r=0.662,P=0.000）。结论：NGF及其受体TrkA在子宫腺肌病中高表达可能参与子宫腺肌病发病机制,而且可能与痛经有关。     

上皮间质转化标记物及Snail在子宫内膜异位症中的表达

目的:研究上皮间质转化标志物(E-cadherin、β-catenin、vimentin)和Snail在子宫内膜异位症(endometriosis,EMs)中的表达。方法:选取40例EMs患者(实验组)异位内膜及在位内膜,同时获取20例非EMs患者(对照组)的正常子宫内膜,采用免疫组化法研究Snail、EMT上皮标志物(E-cadherin、β-catenin)、间质标志物(vimentin)在各内膜组织中的表达,并比较其表达水平。结果:EMs患者异位内膜和在位内膜的EMT上皮标志物E-cadherin、β-catenin表达均显著低于正常内膜的表达(P0.05);EMs患者异位内膜和在位内膜的EMT间质标志物vimentin表达均显著高于正常内膜的表达(P0.05);EMs患者异位内膜和在位内膜中Snail表达显著高于正常内膜的表达(P0.05)。结论:在子宫内膜异位症(EMs)中,Snail、vimentin表达上调,E-cadherin、β-catenin表达下调可能与子宫内膜异位症(EMs)的发生、发展及浸润转移有关。     

ER和PRmRNAs在内异症子宫内膜表达的变化

目的 :探讨雌激素受体 (ER)和孕激素受体 (PR)在子宫内膜异位症 (内异症 )子宫内膜的表达。方法 :利用大鼠内异症动物模型 ,采用逆转录聚合酶链反应 (RT PCR)技术 ,检测子宫内膜ER和PRmRNAs的表达情况。结果 :内异症模型组大鼠异位内膜ER、PRmRNAs的表达低于在位内膜和对照组正常子宫内膜 ,与后两者比较差异有显著性意义 (P <0 .0 1) ;而模型组在位内膜ER、PRmRNAs的表达与正常对照组比较差异无显著性意义 (P >0 .0 5 )。内异症模型组异位内膜ER/PRmRNA比值大于在位内膜和正常子宫内膜ER/PRmRNA比值 (P <0 .0 1)。结论 :内异症大鼠异位内膜ERmRNA表达的相对增高在内异症的发生与发展中起着一定的作用。     

Musashi-1和β-catenin在子宫内膜中的表达及其在内膜异位病灶形成中的作用

目的:检测Musashi-1和β-连环蛋白(β-catenin)在子宫内膜异位症(EMs)患者的在位内膜和异位内膜中的表达,并初步探讨作用机制。方法:2016年9月至2018年9月,收集EMs患者的在位内膜(在位内膜组,28例)、异位内膜(异位内膜组,24例)和非EMs患者的正常内膜(正常内膜组,30例),采用实时荧光定量PCR(Real-time PCR)试验检测Musashi-1和β-catenin在各组内膜组织中的表达情况,并分析Musashi-1和β-catenin在各组内膜组织中的表达相关关系。结果:在位内膜组和异位内膜组中,Musashi-1和β-catenin的相对表达量均明显高于正常内膜组(P0.05),而在位内膜组与异位内膜组之间的差异无统计学意义(P0.05)。在位内膜组和正常内膜组中,增生期的Musashi-1和β-catenin相对表达量显著高于分泌期(P0.05),而异位内膜组中,在增生期和分泌期Musashi-1和β-catenin比较差异无统计学意义(P0.05)。在位内膜组和异位内膜组中,Musashi-1和β-catenin表达之间均呈正相关性(P0.05),而正常内膜组中,两者表达之间无明显相关性(P0.05)。结论:在EMs的发病过程中,干细胞标志物Musashi-1可能通过激活Wnt/β-catenin信号通路参与并促进子宫内膜异位病灶的形成。     

MMP-2、MMP-9及VEGF在子宫内膜异位症中的表达及临床意义

目的:研究基质金属蛋白酶2(MMP-2)、基质金属蛋白酶9(MMP-9)、血管内皮生长因子(VEGF)表达在子宫内膜异位症发生发展中的作用.方法:应用免疫组化二步法检测EMs患者异位内膜36例、在位内膜36例及正常内膜中的MMP-2、MMP-9、VEGF的表达情况.结果:MMP-2、MMP-9、VEGF在异位内膜组中阳性表达率分别为94.4%、91.7%和91.7%,显著高于在位内膜组、正常内膜组(P＜0.05);而在位内膜组和正常内膜组差异无统计学意义(P＞0.05).结论:检测MMP-2、MMP-9、VEGF的表达可用于判断子宫内膜异位症的侵袭转移和评估预后.     

子宫内膜异位症患者血管生成相关基因VEGF和TSP-1 mRNA的表达

本研究的目的在于探讨血管内皮生长因子(VEGF)和血小板反应蛋白-1(TSP-1)在子宫内膜异位症患者的在位内膜、卵巢子宫内膜异位囊肿及正常子宫内膜中的表达及意义。采用q PCR法检测在北京妇产医院接受腹腔镜手术的62例内异症患者的异位内膜、在位内膜及23例不孕症患者正常子宫内膜中VEGF和TSP-1 mRNA的表达水平。结果表明卵巢子宫内膜异位囊肿间质细胞中的VEGF mRNA的表达水平与在位子宫内膜间质细胞相比明显降低(p=0.001),而TSP-1 mRNA的表达水平明显高于后者(p0.001)。VEGF mRNA在卵巢子宫内膜异位囊肿组织中的表达水平明显低于在位子宫内膜组织(p0.001),而TSP-1mRNA的表达水平明显高于后者(p0.001)。VEGF mRNA在在位子宫内膜组织中的表达水平明显高于正常子宫内膜组织(p0.001)。TSP-1 mRNA的表达与后者相比无统计学差异(p=0.221)。血管形成相关基因VEGF和TSP-1在卵巢子宫内膜异位囊肿和在位子宫内膜组织、细胞中表达不同,其可能参与了子宫内膜异位症的发生和发展。     

CD44v6和MMP-2 在子宫内膜异位症组织中的表达及相关性

目的:探讨粘附分子CD44拼构变异体6(CD44v6)和基质金属蛋白酶-2(MMP-2)在子宫内膜异位症(EMs)组织中的表达及相关性。方法:选取40例异位内膜组织标本、40例在位内膜组织标本及40例正常子宫内膜标本,用免疫组织化学方法检测CD44v6和MMP-2的表达,并分析其相关性。结果:CD44v6在异位内膜组的表达明显高于在位内膜组和对照组,且对照组明显高于在位内膜组,差异具有统计学意义(P0.05);CD44v6在在位内膜组和对照组中分泌期的表达明显高于同组增生期,差异具有统计学意义(P0.05)。MMP-2在异位内膜组和在位内膜组的表达明显高于对照组,差异具有统计学意义(P0.01);MMP-2在各组增生期和分泌期表达不规律。异位内膜组中,CD44v6和MMP-2在Ⅲ-Ⅳ期的表达明显高于Ⅰ-Ⅱ期,差异具有统计学意义(P0.01)。Spearman相关性分析结果显示:EMs组织中CD44v6和MMP-2之间呈现正相关性(r=0.724,P0.05);EMs不同分期组织中CD44v6和MMP-2之间亦呈现正相关性(r=0.623,P0.05)。结论:CD44v6和MMP-2在EMs异位内膜中高表达,且有正协同作用,二者可能与EMs的发生发展有关。     

Expression of the chemokine eotaxin and its receptor, CCR3, in human endometrium

Eosinophils are present in human endometrium only immediately before and during menstruation, suggesting a role in that process. The expression of the eosinophil chemoattractant, eotaxin, and its receptor, CCR3, within the human endometrium were investigated by immunohistochemical analysis of tissue sections spanning the entire menstrual cycle. Eotaxin was localized to perivascular cells in the late secretory phase, and it was also identified in eosinophils. However, the highest levels of this chemokine were present in both luminal and glandular epithelial cells during the proliferative and secretory phases of the cycle. Treatment of endometrial tissue with monensin, which blocks protein secretion, increased epithelial immunoreactive eotaxin, substantiating synthesis in these cells. Although the CCR3 receptor was expressed by eosinophils, it was also strongly expressed by endometrial epithelial cells. The CCR3 receptor on purified, cultured endometrial epithelial cells was functional, as assessed by a transient Ca(2+) flux in response to eotaxin. These analyses demonstrate that eotaxin is expressed by endometrial cells and may therefore be involved in the recruitment of eosinophils into this tissue premenstrually. However, the observation that this chemokine and the CCR3 molecule are strongly expressed by epithelial cells throughout the cycle suggests that these proteins may have additional important functions within the endometrium.     

Expression of the C-C chemokine receptor CCR3 in human airway epithelial cells

Chemokine-induced eosinophil chemotaxis is mediated primarily through the C-C chemokine receptor, CCR3. We have now detected CCR3 immunoreactivity on epithelial cells in biopsies of patients with asthma and other respiratory diseases. CCR3 mRNA was detected by Northern blot analysis after TNF-alpha stimulation of the human primary bronchial epithelial cells as well as the epithelial cell line, BEAS-2B; IFN-gamma potentiated the TNF-alpha-induced expression. Western blots and flow cytometry confirmed the expression of CCR3 protein. This receptor is functional based on studies demonstrating eotaxin-induced intracellular Ca(2+) flux and tyrosine phosphorylation of cellular proteins. The specificity of this functional response was confirmed by blocking these signaling events with anti-CCR3 mAb (7B11) or pertussis toxin. Furthermore, (125)I-eotaxin binding assay confirmed that CCR3 expressed on epithelial cells have the expected ligand specificity. These studies indicate that airway epithelial cells express CCR3 and suggest that CCR3 ligands may influence epithelial cell functions.     

Chemokine receptor expression in human endometrium

Chemokines play a role in endometrial physiology and pathology and may affect endometrial receptivity and menstrual shedding. Chemokines exert their effect by binding to their relevant receptors, the expression levels of which may modulate their action. In the present study, we examined the expression of chemokine receptors CXCR1 and CXCR2 (receptors for interleukin-8) and CCR5 (receptor for RANTES [regulated-on-activation, normal-T-cell-expressed and -secreted], macrophage inflammatory protein [MIP]-1alpha, and MIP-1beta) in human endometrium. Human endometria (n = 35) were grouped according to the menstrual cycle phase and examined by immunohistochemistry for CXCR1, CXCR2, and CCR5. In both epithelial and stromal cells, CXCR1 and CXCR2 immunoreactivity was detected. Staining was most prominent at the apical and basal aspects of epithelial cells. Intense CCR5 immunostaining was observed in epithelial and stromal compartments throughout the menstrual cycle. Epithelial and stromal staining for CXCR1 reached a peak at the midsecretory phase, during which it was significantly higher than the level of staining during the proliferative phase (P < 0.05). Immunostaining for CXCR2 and CCR5 showed no significant variation across the menstrual cycle. Expression of interleukin-8 and RANTES in endometrium, together with the presence of their receptors, suggests that autocrine and paracrine interactions involving these chemokines may participate in endometrial physiology.     

Cyclooxygenase-2 up-regulates CCR7 via EP2/EP4 receptor signaling pathways to enhance lymphatic invasion of breast cancer cells

Recent studies demonstrate that cyclooxygenase-2 (COX-2) expression is frequently associated with lymph node metastasis. However, the mechanism by which COX-2 increases the invasion of cancer cells to lymph node is unclear. CCR7 is a chemokine receptor that plays important roles in the mediation of migration of leukocytes and dendritic cells toward lymphatic endothelial cells (LECs) that express receptor ligand CCL21. We found that treatment of prostaglandin E(2) or ectopic expression of COX-2 in MCF-7 cells up-regulated CCR7 expression. On the contrary, knockdown of COX-2 by small hairpin RNA reduced CCR7 in COX-2-overexpressing MDA-MB-231 cells. Interaction of CCR7 and CCL21 was important for the migration of breast cancer cells toward LECs because antibodies against these two molecules inhibited the migration. We also found that COX-2 increased CCR7 expression via the EP2 and EP4 receptor in breast cancer cells. EP2 and EP4 agonists stimulated CCR7 in MCF-7 cells, whereas antagonists or small hairpin RNA of EP2 and EP4 attenuated CCR7 in MDA-MB-231 cells. Protein kinase A and AKT kinase were involved in COX-2-induced CCR7. Pathological analysis demonstrated that COX-2 overexpression was associated with CCR7, EP2, and EP4 expressions in breast tumor tissues. In addition, CCR7 expression in COX-2-overexpressing tumors was significantly correlated with lymph node metastasis. Collectively, we suggest that CCR7 is a down-stream target for COX-2 to enhance the migration of breast cancer cells toward LECs and to promote lymphatic invasion.     

Expression and Use of Human Immunodeficiency Virus Type 1 Coreceptors by Human Alveolar Macrophages

Human immunodeficiency virus type 1 (HIV-1) requires, in addition to CD4, coreceptors of the CC or CXC chemokine families for productive infection of T cells and cells of the monocyte-macrophage lineage. Based on the hypothesis that coreceptor expression on alveolar macrophages (AM) may influence HIV-1 infection of AM in the lung, this study analyzes the expression and utilization of HIV-1 coreceptors on AM of healthy individuals. AM were productively infected with five different primary isolates of HIV-1. Levels of surface expression of CCR5, CXCR4, and CD4 were low compared to those of blood monocytes, but CCR3 was not detectable. mRNA for CCR5, CXCR4, CCR2, and CCR3 were all detectable, but to varying degrees and with variability among donors. Expression of CCR5, CXCR4, and CCR2 mRNA was downregulated following stimulation with lipopolysaccharide (LPS). In contrast, secretion of the chemokines RANTES, MIP-1alpha, and MIP-1beta was upregulated with LPS stimulation. Interestingly, HIV-1 replication was diminished following LPS stimulation. Infection of AM with HIV-1 in the presence of the CC chemokines demonstrated blocking of infection. Together, these studies demonstrate that AM can be infected by a variety of primary HIV-1 isolates, AM express a variety of chemokine receptors, the dominant coreceptor used for HIV entry into AM is CCR5, the expression of these receptors is dependent on the state of activation of AM, and the ability of HIV-1 to infect AM may be modulated by expression of the chemokine receptors and by chemokines per se.     

Differential expression of chemokine receptors on peripheral blood B cells from patients with rheumatoid arthritis and systemic lupus erythematosus

Chemokines and their receptors are essential in the recruitment and positioning of lymphocytes. To address the question of B cell migration into the inflamed synovial tissue of patients with rheumatoid arthritis (RA), peripheral blood naive B cells, memory B cells and plasma cells were analyzed for cell surface expression of the chemokine receptors CXCR3, CXCR4, CXCR5, CCR5, CCR6, CCR7 and CCR9. For comparison, B cells in the peripheral blood of patients with the autoimmune disease systemic lupus erythematosus (SLE) or with the degenerative disease osteoarthritis (OA) were analyzed. Expression levels of chemokine receptors were measured by flow cytometry and were compared between the different patient groups and healthy individuals. The analysis of chemokine receptor expression showed that the majority of peripheral blood B cells is positive for CXCR3, CXCR4, CXCR5, CCR6 and CCR7. Whereas a small fraction of B cells were positive for CCR5, practically no expression of CCR9 was found. In comparison with healthy individuals, in patients with RA a significant fraction of B cells showed a decreased expression of CXCR5 and CCR6 and increased levels of CXCR3. The downregulation of CXCR5 correlated with an upregulation of CXCR3. In patients with SLE, significant changes in CXCR5 expression were seen. The functionality of the chemokine receptors CXCR3 and CXCR4 was demonstrated by transmigration assays with the chemokines CXCL10 and CXCL12, respectively. Our results suggest that chronic inflammation leads to modulation of chemokine receptor expression on peripheral blood B cells. However, differences between patients with RA and patients with SLE point toward a disease-specific regulation of receptor expression. These differences may influence the migrational behavior of B cells.     

Dendritic cells support sequential reprogramming of chemoattractant receptor profiles during naive to effector T cell differentiation

T cells undergo chemokine receptor switches during activation and differentiation in secondary lymphoid tissues. Here we present evidence that dendritic cells can induce changes in T cell expression of chemokine receptors in two continuous steps. In the first switch over a 4-5 day period, dendritic cells up-regulate T cell expression of CXCR3 and CXCR5. Additional stimulation leads to the second switch: down-regulation of lymphoid tissue homing related CCR7 and CXCR5, and up-regulation of Th1/2 effector tissue-targeting chemoattractant receptors such as CCR4, CCR5, CXCR6, and CRTH2. We show that IL-4 and IL-12 can determine the fate of the secondary chemokine receptor switch. IL-4 enhances the generation of CCR4(+) and CRTH2(+) T cells, and suppresses the generation of CXCR3(+) T cells and CCR7(-) T cells, while IL-12 suppresses the level of CCR4 in responding T cells. Furthermore, IL-4 has positive effects on generation of CXCR5(+) and CCR7(+) T cells during the second switch. Our study suggests that the sequential switches in chemokine receptor expression occur during naive T cell interaction with dendritic cells. The first switch of T cell chemokine receptor expression is consistent with the fact that activated T cells migrate within lymphoid tissues for interaction with B and dendritic cells, while the second switch predicts the trafficking behavior of effector T cells away from lymphoid tissues to effector tissue sites.     

Roles of SLC/CCL21 and CCR7 in human kidney for mesangial proliferation, migration, apoptosis, and tissue homeostasis

The release of chemokines by intrinsic renal cells is an important mechanism for the regulation of leukocyte trafficking during renal inflammation. The expression of chemokine receptors by intrinsic renal cells such as mesangial cells (MC) suggests an expanded role for chemokine-chemokine receptor biology in local immunomodulation and potentially glomerular homeostasis. By immunohistochemistry we found the chemokine receptor CCR7 expressed in a mesangial pattern while the CCR7 ligand SLC/CCL21 showed a podocyte-specific expression. CCR7 expression was further characterized by RT-PCR, RNase protection assays, and FACS analysis of cultured human MC, and was found to be constitutively present. Real-time PCR of microdissected glomeruli confirmed the expression of SLC/CCL21. A functional role for CCR7 was demonstrated for human MC migration and proliferation. A protective effect of SLC/CCL21 was shown for MC survival in Fas Ab-induced apoptosis. Finally, "wound healing" was enhanced in the presence of SLC/CCL21 in an in vitro injury model. The constitutive glomerular expression of CCR7 and its ligand SLC/CCL21 in adjacent cell types of the human kidney suggests novel biological functions of this chemokine/chemokine receptor pair and a potential role in processes involved in glomerular homeostasis and regeneration.     

γδ T cell homing to skin and migration to skin-draining lymph nodes is CCR7 independent

In most species, γδ T cells preferentially reside in epithelial tissues like the skin. Lymph duct cannulation experiments in cattle revealed that bovine dermal γδ T cells are able to migrate from the skin to the draining lymph nodes via the afferent lymph. For αβ T cells, it is generally accepted that epithelial and mucosal tissue egress is regulated by expression of the CCR7 chemokine receptor. In this study, we tracked the migratory route of bovine lymph-derived γδ T cells and examined their CCR7 cell surface expression in several compartments along this route. Total lymph cells from afferent and efferent origin were labeled with PKH fluorescent dyes and injected into the bloodstream. PKH(+) cells already reappeared in the afferent lymph after 4 h. The vast majority of the PKH(+) cells retrieved from the afferent lymph were of the WC1(+) γδ T cell phenotype, proving that this PKH(+) γδ T cell subset is able to home to and subsequently exit the skin. PKH(+) γδ T cells from afferent and efferent lymph lack CCR7 surface expression and display high levels of CD62L compared with CD4 T cells, which do express CCR7. Skin homing receptors CCR4 and CCR10 in contrast were transcribed by both CD4 and γδ T cells. Our findings suggest that γδ T cell skin egress and migration into the peripheral lymphatics is CCR7-independent and possibly mediated by CD62L expression.