Eitner F, Cui Y, Hudkins K L, Anderson D M, Schmidt A, Morton W R, Alpers C E
Department of Pathology, University of Washington, Seattle, USA.
Kidney Int. 1998 Dec;54(6):1945-54. doi: 10.1046/j.1523-1755.1998.00211.x.
The chemokine receptor, CCR5, has been identified as an essential co-receptor with CD4, which permits entry of human immunodeficiency virus (HIV) into mammalian cells. This receptor may also mediate leukocyte and parenchymal responses to injury by virtue of its binding to locally released chemokines such as RANTES, MIP-1 alpha and MIP-1 beta during inflammation. The localization of CCR5 in human or primate kidney is unknown. In this study we sought to identify sites of CCR5 synthesis through localization of mRNA coding for this peptide.
CCR5 cDNA cloned into an expression vector was transcribed into a 1.1 Kb antisense riboprobe that was utilized for in situ hybridization (ISH) and Northern blotting studies.
Northern analysis demonstrated positive hybridization for CCR5 mRNA in total RNA isolated from allograft nephrectomy tissue with features of severe transplant rejection as well as in kidney tissue with focal interstitial nephritis. No comparable hybridization signal was achieved with human kidney tissue uninvolved by disease. CCR5 mRNA was not identified in intrinsic renal cell types by ISH in normal human (N = 6), normal macaque kidney (N = 5), in kidneys from macaques with established infection by HIV-2 (N = 9), kidneys from macaques infected with HIV-1 (N = 4), nor in kidneys from SIV-infected macaques (N = 5). CCR5 was identified by ISH in human kidneys with features of interstitial nephritis (N = 3) and in rejected human allograft kidneys (N = 14). The expression of CCR5 was restricted to infiltrating mononuclear leukocytes at sites of chronic tubulointerstitial injury and at sites of vascular and interestitial rejection, respectively.
Understanding the localization of CCR5 as well as other chemokine receptors may help us understand how specificity in leukocyte trafficking is achieved in renal inflammatory processes such as allograft rejection and interstitial nephritis. They provide additional evidence that chemokines may be critical mediators of leukocyte trafficking in renal allograft rejection. These findings may account in part for the difficulty in demonstrating HIV infection of renal cells in human HIV infection, since these cells appear to lack constitutive expression of an essential co-receptor needed for viral entry.
趋化因子受体CCR5已被确定为与CD4协同作用的重要共受体，它可使人类免疫缺陷病毒（HIV）进入哺乳动物细胞。该受体还可能通过在炎症过程中与局部释放的趋化因子（如RANTES、MIP-1α和MIP-1β）结合，介导白细胞和实质细胞对损伤的反应。CCR5在人或灵长类动物肾脏中的定位尚不清楚。在本研究中，我们试图通过定位编码该肽的mRNA来确定CCR5的合成位点。
将克隆到表达载体中的CCR5 cDNA转录成1.1 Kb的反义核糖探针，用于原位杂交（ISH）和Northern印迹研究。
Northern分析显示，从具有严重移植排斥特征的同种异体肾切除组织以及局灶性间质性肾炎的肾脏组织中分离的总RNA中，CCR5 mRNA呈阳性杂交。在未受疾病影响的人肾组织中未获得类似的杂交信号。在正常人（N = 6）、正常猕猴肾（N = 5）、感染HIV-2的猕猴肾（N = 9）、感染HIV-1的猕猴肾（N = 4）以及感染SIV的猕猴肾（N = 5）中，ISH均未在肾固有细胞类型中鉴定出CCR5 mRNA。在具有间质性肾炎特征的人肾（N = 3）和被排斥的人同种异体肾（N = 14）中，ISH鉴定出了CCR5。CCR5的表达分别局限于慢性肾小管间质损伤部位以及血管和间质排斥部位的浸润性单核白细胞。
了解CCR5以及其他趋化因子受体的定位可能有助于我们理解在同种异体移植排斥和间质性肾炎等肾脏炎症过程中，白细胞运输的特异性是如何实现的。它们提供了额外的证据，表明趋化因子可能是肾脏同种异体移植排斥中白细胞运输的关键介质。这些发现可能部分解释了在人类HIV感染中难以证明肾细胞感染HIV的原因，因为这些细胞似乎缺乏病毒进入所需的重要共受体的组成型表达。
