趋化因子受体CCR5在同种大鼠心脏移植局部的表达

目的探讨急性排斥反应过程中CCR5基因与蛋白在移植心脏局部表达的意义及环孢素(CsA)的影响。方法施行大鼠异位心脏移植术,移植大鼠分为3组,每组45只,对照组5只:SD大鼠间的移植为同系移植组(A组),Wistar至SD大鼠的移植分为未用CsA干预组(B组)及CsA干预组(C组),健康SD大鼠为对照组。分别采用RT-PCR方法和免疫组化方法检测CCR5 mRNA和蛋白的表达。结果CCR5 mRNA在A组各时间点和对照组均呈阴性表达,在B组的表达变化与急性排斥反应的进程相关,术后第3天CCR5 mRNA表达上调至峰值(1.4±0.33);C组应用CsA后,CCR5 mRNA表达峰值(0.5±0.29)显著低于B组(t=2.11,P<0.05)。CCR5蛋白定位于移植心脏间质单个核浸润细胞。结论CCR5基因与蛋白的表达上调与急性排斥反应过程中移植物间质CCR5阳性单个核细胞浸润密切相关,可能为急性排斥反应的早期诊断提供帮助;CsA抑制CCR5阳性细胞的浸润及CCR5的表达水平。     

Inhibitory effects of whole and parotid saliva on immunomodulators

Based on the presence of cytokines in whole saliva and their association with resistance and susceptibility to infectious disease, the present study was designed to evaluate the diagnostic potential of a large panel of cytokines and chemokines in saliva. Despite the endogenous presence of Th1/Th2 and pro-inflammatory cytokines and several chemokines in whole and parotid saliva of most individuals tested, the detection of known concentrations of several recombinant cytokines and chemokines was inhibited immediately following their addition to each type of saliva. In contrast, purified immunoglobulins were unaffected by either whole or parotid saliva. Further studies revealed that the inhibition of immunoreactivity involved sequestration of the majority of cytokines affected and degradation of chemokines. These results suggest that absolute concentrations of cytokines/chemokines may not be fully detectable in saliva. Therefore, the diagnostic value of any cytokine/chemokine is questionable and should be evaluated independently as such.     

Interleukin-8 secretion following cardiopulmonary bypass in children as a marker of early postoperative morbidity

BACKGROUND: Interleukin (IL)-8, an 8 kDa peptide, is the first chemoattractant identified as being specific for neutrophils. Its possible association with early postoperative morbidity following cardiopulmonary bypass (CPB) in infants and children is unknown. This prospective cohort study sought possible roles of IL-8 in the inflammatory response to CPB and investigated if changes in IL-8 levels and clinical course and outcome were related. METHODS: IL-8 levels were measured in 16 children undergoing CPB. Systemic blood was collected after induction of anaesthesia (baseline), at 15 min after CPB onset and cessation, and at 1, 4, 8, 12 and 24 h thereafter. RESULTS: Correlation coefficients between IL-8 levels and CPB time ranged from 0.45 to 0.55, heart rate 0.41--0.44, surgical time 0.41--0.63 and pH --0.56 to --0.50 (P < 0.05 for all parameters). Univariate analyses showed that patients requiring inotropic support and those with tachycardia had significantly higher postoperative IL-8 levels (P < 0.05). Furthermore, IL-8 levels were significantly higher in patients with surgical times > 200 min and in patients with an aortic clamp in place for > 65 min. CONCLUSIONS: There was an association between IL-8 and early postoperative heart rate, and the need for inotropic support IL-8 correlated positively with surgical time, CPB time and heart rate and negatively with pH. IL-8 release may be related to some of the haemodynamic changes in the early postoperative course following CPB. The relationship between IL-8 and late markers of patient outcome in high-risk infants awaits further studies.     

Chemokine and cytokine expression in murine intestinal epithelium following Nippostrongylus brasiliensis infection

Infection of mice with the nematode parasite Nippostrongylus brasiliensis results in a well characterized intestinal mastocytosis with intraepithelial migration of mucosal mast cells (MMC). The molecules mediating this response are unknown. We examined expression of several putative mast cell chemoattractants in intestinal epithelium following N. brasiliensis infection. Expression of the chemokines monocyte chemoattractant protein-1 (MCP-1), macrophage inflammatory protein-1 alpha (MIP-1alpha), RANTES (regulated on activation normal T-cell expressed and secreted), fractalkine, and thymocyte expressed chemokine (TECK); and the cytokines stem cell factor (SCF) and transforming growth factor beta1 (TGFbeta1), was constitutive and no alteration was detected following infection. MCP-1 expression was also constitutive but at much lower levels and increased expression was detected on days 7 and 14 postinfection. Expression of MCP-1 in whole jejunum was at much higher levels than in epithelium. Constitutive expression of MCP-1, MIP-1alpha and TGFbeta1 was also detected in cultured bone marrow-derived homologues of MMC. In an intestinal epithelial cell line (CMT-93), there was constitutive expression of SCF, TGFalpha1, fractalkine and MCP-1. The results show that, in vivo, epithelium is a potentially important source of mast cell chemoattractants.     

The role of CC and CXC chemokines in cardiac allograft rejection in rats

Acute cellular rejection is due in part to an upregulation of chemokine genes, resulting in eventual cell-mediated cytotoxicity. The role of chemokines in acute cardiac allograft rejection is not fully characterized presently. These studies compared the patterns of expression for multiple chemokines in rodent cardiac allograft rejection. Allogeneic transplants were performed from Brown-Norway donors to Lewis recipients. Survival studies utilized daily administration of neutralizing antisera to MCP-1, CINC, and MIP-1alpha. Patterns of mRNA and protein expression were determined by Northern blots and immunohistochemistry. Allogeneic controls rejected at mean of 6.5 days. Neutralization of MCP-1 (10.8 days, P<0.001) and MIP-1alpha (7.5 days, P=0.004) function, but not CINC (6.2 days, P>0.05), significantly prolonged allograft survival. Message expression for the beta chemokines studied were increased by day 2 and continued to increase until day 6 just before rejection, while CINC levels did not change as dramatically after day 2. Chemokine protein levels mirrored mRNA patterns by IHC analysis. MCP-1 and MIP-1alpha appear to play regulatory roles in cardiac allograft rejection, while CINC is expressed, but not functional, in injury development. Beta chemokine activity should be studied further in hope of developing more targeted immunosuppression, or identifying specific chemokines that may be useful for immunosurveillance purposes.     

Expression of interleukin-6 and monocyte chemoattractant protein-1 by peritoneal sub-mesothelial cells during abdominal operations

Cytokines and chemokines including interleukin-6 (IL-6) and monocyte chemoattractant protein-1 (MCP-1) are secreted in response to major abdominal operations. The aim of this study was to identify the peritoneal cells that produce IL-6 and MCP-1. Samples of peritoneal tissue were taken from patients at the beginning and end of major abdominal operations. The samples were incubated in culture medium on microtitre plates for 5 h. The concentrations of IL-6 and MCP-1 were measured in culture supernatants by enzyme-linked immunosorbent assay (ELISA). In paraffin sections, cells that expressed IL-6 or MCP-1 were identified by combined in situ hybridization and immunohistochemistry. Antibodies against CD68, CD34, actin, and calretinin were included in these experiments. The median production of IL-6 increased significantly from 6256 pg/ml at the start of the operation to 20,000 pg/ml at the end. Production of MCP-1 rose from 7700 pg/ml to 11,820 pg/ml. IL-6 mRNA was mainly confined to endothelial cells. MCP-1 was expressed by a broader range of cells, consisting of actin-positive smooth muscle cells and endothelial cells, fibroblast-like cells, as well as occasional macrophages and mesothelial cells. Peritoneal endothelial cells contribute to the transient increase in concentrations of IL-6 in the circulation after surgical trauma. Recruitment of monocytes to the site of the trauma seems to be mainly effected by actin-positive smooth muscle cells and endothelial cells.     

Chemokine control of lymphocyte trafficking: a general overview

Chemokines are a large family of small, generally secreted polypeptides which guide lymphocyte movement throughout the body by controlling integrin avidity and inducing migration. Here, we look at recent, exciting findings on chemokine function throughout lymphocyte development and co-ordinated T and B cell migration during immune responses. Finally, we will review data on the regional control of immunity by tissue-specific chemokine receptors on effector/memory lymphocytes.     

Low prevalence of antibodies and other plasma factors binding to CC chemokines and IL-2 in HIV-positive patients

Neutralizing cytokine antibodies are found in healthy and diseased individuals, including patients treated with recombinant cytokines. Identification of CCR-5 as co-receptor for HIV has focused interest on CC chemokines and their potential therapeutic use. Chemokine-binding components in plasma of HIV-infected patients were therefore assessed by radioimmunoassay and radioreceptor assay. IgG from 4/505 HIV patients and 9/2000 healthy controls (p>0.05) bound rMIP-1alpha and rMIP-1beta, but not rRANTES. No other plasma factors bound the chemokines. The antibodies inhibited receptor binding of both chemokines. There was no association between presence of antibodies and disease stage or HIV progression rate. Three of 11 patients treated with rIL-2 developed IgG antibodies suppressing cellular binding and growth promotion of rIL-2. Hence, circulating factors, including antibodies MIP-1alpha/MIP-1beta, are uncommon in healthy individuals and HIV patients, and are apparently without prognostic significance. In contrast to earlier reports, IL-2 antibodies were found only in HIV patients treated with rIL-2.