Expression of ICAM-1, ICAM-2, NCAM-1 and VCAM-1 by human synovial cells exposed to Borrelia burgdorferi in vitro

The interaction of resident tissue cells with migratory inflammatory cells is essential for the recruitment of immune effector cells to inflammatory sites. The sustained expression of adhesion molecules in the synovium of patients with chronic Lyme arthritis seems to contribute to this chronic inflammation. Whether cell adhesion molecules influence the early steps of Borreliosis is unclear. Therefore, we examined the expression of ICAM-1, ICAM-2, VCAM-1 and NCAM-1 in synovial cells exposed to two different Borrelia burgdorferi sensu stricto strains Geho and B31. The mRNA expression of ICAM-1, ICAM-2, VCAM-1 and NCAM-1 was not changed in synovial cells exposed to B31. Whereas ICAM-2 and VCAM-1 was upregulated, NCAM-1 mRNA was downregulated and ICAM-1 mRNA was unchanged by strain Geho. The ICAM-1 protein expression on the synovial cell surface was downregulated by both strains. Differential regulation of adhesion molecule mRNA, and subsequent high turnover or elevated shedding from the cell membrane may contribute to early pathogenesis in Lyme arthritis.     

New T-lymphocytic cell lines for studying cell infectability by human immunodeficiency virus

We identified five human T-lymphoid cell lines (PB-1, Sez-4, C19PL, HUT 102B and ATL-2) which highly express CD4 in addition to CXCR4 and CCR5. In order to evaluate if these cells are infectabile by human immunodeficiency virus (HIV) and could be employed as a model in HIV research we exposed these cell lines to X4 (T-cell tropic) and R5 (macrophage tropic) and subsequently tried to correlate their infectability with (i) level of chemokine coreceptor (CXCR4 and CCR5) expression, (ii) coreceptor functionality (calcium flux, chemotaxis and phosphorylation of MAPK p42/44 and AKT) and (iii) endogenous expression and secretion of HIV-related chemokines which compete with the virus for binding to CXCR4 (SDF-1/CXCL12) or CCR5 (MIP-1beta/CCL4, MIP-1alpha/CCL3, RANTES/CCL5, MCP-2/CCL8, MCP-3/CCL7 and MCP-4/CCL13). We demonstrated that while PB-1 cells are infectable by both X4 and R5 HIV, Sez-4, C91PL, HUT 102B and ATL-2 cells were infected by X4 HIV only. Moreover, we noticed that the susceptibility of these cells to HIV did not correspond either with the level of surface expression or with the functionality of CXCR4 or CCR5; however, it was modulated to some degree by the endogenously secreted HIV-related chemokines. Thus all five mature T-cell lines described here may provide useful new models for studying various aspects of HIV infection. In addition we demonstrate that the infectability of cells by HIV is modulated by so far unidentified intrinsic factors as well as some already known endogenously secreted chemokines. The identification of these factors may be important for developing new strategies to protect cells from HIV infection.     

CCR5-binding chemokines modulate CXCL12 (SDF-1)-induced responses of progenitor B cells in human bone marrow through heterologous desensitization of the CXCR4 chemokine receptor

Although the SDF-1 (CXCL12)/CXCR4 axis is important for B-cell development, it is not yet clear to what extent CC chemokines might influence B lymphopoiesis. In the current study, we characterized CC chemokine receptor 5 (CCR5) expression and function of primary progenitor B-cell populations in human bone marrow. CCR5 was expressed on all bone marrow B cells at levels between 150 and 200 molecules per cell. Stimulation of bone marrow B cells with the CCR5-binding chemokine macrophage inflammatory protein 1beta (MIP-1beta; CCL4) did not cause chemotaxis, but CCL4 was able to trigger potent calcium mobilization responses and activation of the mitogen-activated protein kinase (MAPK) pathway in developing B cells. We also determined that CCR5-binding chemokines MIP-1alpha (CCL3), CCL4, and RANTES (CCL5), specifically by signaling through CCR5, could affect all progenitor B-cell populations through a novel mechanism involving heterologous desensitization of CXCR4. This cross-desensitization of CXCR4 was manifested by the inhibition of CXCL12-induced calcium mobilization, MAPK activation, and chemotaxis. These findings indicate that CCR5 can indeed mediate biologic responses of bone marrow B cells, even though these cell populations express low levels of CCR5 on their cell surface. Thus, by modulation of CXCR4 function, signaling through CCR5 may influence B lymphopoiesis by affecting the migration and maturation of B-cell progenitors in the bone marrow microenvironment.     

Lack of association of some chemokine system polymorphisms with the risks of death and hepatocellular carcinoma occurrence in patients with alcoholic cirrhosis: a prospective study

BACKGROUND: Polymorphisms in genes encoding for the chemokines stromal cell-derived factor-1 (SDF-1)/CXCL12, monocyte chemotactic protein-1 (MCP-1)/CCL2, or for the chemokine receptors, CC chemokine receptor 5 (CCR5) or CC chemokine receptor 2 (CCR2) have been associated with the progression of hepatitis C virus-related liver injury and with various cancer development. Their influence on the prognosis of alcoholic liver disease is unknown. PATIENTS AND METHODS: SDF-1 3'A, MCP-1(-2518), CCR5-Delta32 and CCR2-64I polymorphisms, SDF-1alpha, regulated upon activation normal T cells expressed and secreted (RANTES)/CCL5 and MCP-1 sera levels were determined in 222 alcoholic patients, included at the time of cirrhosis diagnosis and prospectively followed up. RESULTS: Carriers and noncarriers of each genetic marker had similar baseline characteristics estimating the severity of liver disease. Mean time of follow-up of the cohort was 62.9+/-43.2 months. One hundred and forty-seven out of 222 (66.3%) patients were alive at the end of the study. The occurrence of death (75/222; 33.7%) or hepatocellular carcinoma (67/222; 30.1%) during follow-up was similar among carriers and noncarriers of each polymorphism. No association between the carriage of mutated alleles and chemokine sera levels was found: CCR5-Delta32/RANTES, SDF-1 3'A/SDF-1alpha and CCR2-64I or MCP-1(-2518)/MCP-1. Baseline RANTES, SDF-1alpha and MCP-1 sera levels were associated neither with the risk of death nor with the risk of hepatocellular carcinoma. CONCLUSIONS: The present study suggests the lack of association of SDF-1 3'A, MCP-1(-2518), CCR5-Delta32 and CCR2-64I polymorphisms with death and hepatocellular carcinoma occurrence in cirrhotic alcoholic patients.     

High levels of inflammatory chemokines and cytokines in joint fluid and synovial tissue throughout the course of antibiotic-refractory lyme arthritis

OBJECTIVE: To investigate the possible role of chemokines and cytokines in the pathogenesis of Lyme arthritis. METHODS: Using cytometric bead array and flow cytometry techniques, chemokine and cytokine levels were determined in 65 synovial fluid (SF) samples and 7 synovial tissue (ST) samples from 17 patients with antibiotic-responsive Lyme arthritis and 35 patients with antibiotic-refractory Lyme arthritis seen during the past 18 years. In the ST samples, expression of chemokine receptors was measured using immunohistochemistry. RESULTS: Before or during antibiotic therapy, when the majority of patients had positive polymerase chain reaction (PCR) results for Borrelia burgdorferi DNA, SF from patients with antibiotic-refractory arthritis contained exceptionally high levels of Th1 chemoattractants and cytokines, particularly CXCL9 and interferon-gamma (IFNgamma). Compared with the patients whose arthritis was responsive to antibiotic treatment, those with antibiotic-refractory arthritis had significantly higher levels of CXCL9 and CXCL10 (both P相似文献   

Differential gene expression during capillary morphogenesis in a microcarrier-based three-dimensional in vitro model of angiogenesis with focus on chemokines and chemokine receptors

AIM: To globally compare the gene expression profiles during the capillary morphogenesis of human microvascular endothelial cells (HMVECs) in an in vitro angiogeness system with affymetrix oligonucleotide array. METHODS: A microcarrier-based in vitro angiogenesis system was developed, in which ECs migrated into the matrix, proliferated, and formed capillary sprouts. The sprouts elongated, branched and formed networks. The total RNA samples from the HMVECs at the selected time points (0.5, 24, and 72 h) during the capillary morphogenesis were used for microarray analyses, and the data were processed with the softwares provided by the manufacturers. The expression patterns of some genes were validated and confirmed by semi-quantitative RT-PCR. The regulated genes were grouped based on their molecular functions and expression patterns, and among them the expression of chemokines and chemokine receptors was specially examined and their functional implications were analyzed. RESULTS: A total of 1 961 genes were up- or downreg-ulated two-folds or above, and among them, 468 genes were up- or down-regulated three-folds or above. The regulated genes could be grouped into categories based on their molecular functions, and were also clustered into six groups based on their patterns of expression. As for chemokines and chemokine receptors, CXCL1/GRO-α, CXCL2/GRO-β, CXCL5/ENA-78, CXCL6/GCP2, IL-8/CXCL8, CXCL12/SDF-1, CXCL9/Mig, CXC11/ITAC, OOCL1/fractalkine, CCL2/MCP-1, CCL3, CCL5/RANTES, CCL7, CCL15, CCL21, CCL23, CCL28, and CCR1, CCR9, CXCR4 were identified. Moreover, these genes demonstrated different changing patterns during the capillary morphogenesis, which implied that they might have different roles in the sequential process. Among the chemokines identified, CCL2/MCP-1, CCL5/RANTES and CX3CL1 were specially up-regulated at the 24-h time point when the sprouting characterized the morphological change. It was thus suggested that they might exert crucial roles at the early stage of angiogenesis. CONCLUSION: The present study demonstrates a global profile of gene expression during endothelial capillary morphogenesis, and the results provide us much information about the molecular mechanisms of angiogenesis, with which further evaluation of individual genes can be conducted.     

莱姆病螺旋体83kD原浆柱蛋白特异性区段的基因克隆与表达研究

目的　为莱姆病血清学诊断和基因工程亚单位疫苗研制提供靶抗原。方法　根据莱姆病螺旋体 83kD原浆柱蛋白 (p83)特异性区段的基因序列 ,设计一对引物 ,采用PCR技术从莱姆病螺旋体B31株基因组DNA中扩增p83特异性区段的基因片段 ,纯化扩增产物 ,用BamHI和EcoRI双酶切后定向克隆入质粒载体pBK -CMV ;转化大肠杆菌筛选重组克隆。用BamHI和EcoRI双酶切、PCR扩增和DNA序列测定对重组质粒进行鉴定 ,将重组质粒转化大肠杆菌 ,IPTG诱导表达后进行SPS -PAGE和Western -blotting分析。结果　 1)从莱姆病螺旋体B31株基因组DNA中扩增出p83特异性区段的基因片段 ;2 )将扩增所得的目的基因片段正向插入pBK -CMV的BamHI和EcoRI位点 ,获得重组质粒pBX1。 3)pBX1在大肠杆菌中诱导表达后获得 2 9kD含 β -半乳糖苷酶氨基末端片段的重组抗原。 结论　成功构建了莱姆病螺旋体 83kD原浆柱蛋白特异性区段的基因重组表达载体 ,并在大肠杆菌中获得了稳定的表达 ,为进一步研究该重组抗原在莱姆病血清学诊断和基因工程亚单位疫苗研制中的应用奠定了基础     

Divergent expression of inflammatory dermal chemokines in cutaneous leishmaniasis

Human leishmaniasis is caused by protozoan Leishmania (L.) parasites and comprises a heterogeneous group of clinical appearances ranging from visceral to cutaneous leishmaniasis. In the New World, L. mexicana mediates American cutaneous leishmaniasis, one of the most common forms of this disease. Two different disease progressions can be observed: (i) self-healing localized cutaneous leishmaniasis (LCL) and (ii) progressive diffuse cutaneous leishmaniasis (DCL). These different forms are associated with a T helper 1 (Th1) or Th2 response, respectively, and are additionally characterized by opposing dermal chemokine profiles. Lesions of LCL show high expression of CCL2/MCP-1, CXCL9/MIG, CXCL10/IP-10 and only low amounts of CCL3/MIP-1alpha. In contrast, lesions of chronic DCL are dominated by the expression of CCL3/MIP-1alpha. This finding implies that CCL2/MCP-1 contributes to the healing process. Indeed, CCL2/MCP-1 induces leishmanicidal activities in human monocytes in contrast to CCL3/MIP-1alpha. This effect is enhanced by interferon-gamma and abrogated by interleukin-4. In the murine model of leishmaniasis, the impact of CCL2/MCP-1 is well documented. Normally resistant mice become susceptible for Leishmania infections if CCR2, the receptor for CCL2/MCP-1, is knocked out. Based on this evidence, we propose that tissue specific expression of these small molecules actively regulates cell traffic and tissue localization of effector cells and, additionally, has direct immunological effects.     

Platelet chemokines and chemokine receptors: linking hemostasis,inflammation, and host defense

Blood platelets play critical roles in hemostasis, providing rapid essential protection against bleeding and catalyzing the important slower formation of stable blood clots via the coagulation cascade. They are also involved in protection from infection by phagocytosis of pathogens and by secreting chemokines that attract leukocytes. Platelet function usually is activated by primary agonists such as adenosine diphosphate (ADP), thrombin, and collagen, whereas secondary agonists like adrenalin do not induce aggregation on their own but become highly effective in the presence of low levels of primary agonists. Current research has revealed that chemokines represent an important additional class of agonists capable of causing significant activation of platelet function. Early work on platelet alpha-granule proteins suggested that platelet factor 4, now known as CXCL4, modulated aggregation and secretion induced by low agonist levels. Subsequent reports revealed the presence in platelets of messenger RNA for several additional chemokines and chemokine receptors. Three chemokines in particular, CXCL12 (SDF-1), CCL17 (TARC), and CCL22 (MDC), recently have been shown to be strong and rapid activators of platelet aggregation and adhesion after their binding to platelet CXCR4 or CCR4, when acting in combination with low levels of primary agonists. CXCL12 can be secreted by endothelial cells and is present in atherosclerotic plaques, whereas CCL17 and CCL22 are secreted by monocytes and macrophages. Platelet activation leads to the release of alpha-granule chemokines, including CCL3 (MIP-1alpha), CCL5 (RANTES), CCL7 (MCP-3), CCL17, CXCL1 (growth-regulated oncogene-alpha), CXCL5 (ENA-78), and CXCL8 (IL-8), which attract leukocytes and further activate other platelets. These findings help to provide a direct linkage between hemostasis, infection, and inflammation and the development of atherosclerosis.     

Chemokine expression in myocardial ischemia: MIP-2 dependent MCP-1 expression protects cardiomyocytes from cell death

Chemokines are small molecular weight proteins that play important roles in inflammation. Originally described as chemotactic cytokines, chemokines stimulate the influx of leukocytes into specific tissue compartments. These molecules also modulate gene expression in both infiltrating and resident cells to mediate a vast array of cellular functions, and their importance in disease processes has been well documented. This study examined the expression of chemokines during myocardial ischemia and established a pathway by which two, MIP-2 and JE/MCP-1, modulate cardiac myocyte viability during this process. To focus on the direct effects of chemokines on these cells, a mouse model of ischemia without reperfusion was used. The expression of chemokines and chemokine receptors was induced in the left ventricular free wall as early as 1 h post-ischemia, with the most significant increases in MIP-2 (CXCL2) and JE/MCP-1 (CCL2). Expression of their respective receptors, CXCR2 and CCR2, was also induced. Similar changes in gene expression occurred at the mRNA and protein levels in isolated neonatal mouse cardiac myocytes stimulated by hypoxia. Antibody to MIP-2 inhibited hypoxia-induced JE/MCP-1 expression, demonstrating that MIP-2 is critical for this event. Moreover, in vivo intramyocardial injection of either an adenovirus expressing MIP-2 or the recombinant protein itself was sufficient to upregulate JE/MCP-1 production even in the absence of ischemia. Thus, MIP-2 regulates JE/MCP-1 expression both in cell culture and in vivo. Furthermore, JE/MCP-1 markedly decreased hypoxia-induced cell death in cultured cardiac myocytes. Thus, JE/MCP-1 appears to mediate an unanticipated survival pathway in target cardiac myocytes themselves. These findings indicate an important role for MIP-2 and JE/MCP-1 in regulating the response of cardiac myocytes to myocardial ischemia.     

Chemokine receptor expression in rat adjuvant-induced arthritis

OBJECTIVE: Chemokine receptors mediate leukocyte migration into inflamed rheumatoid arthritis (RA) synovial tissue (ST). Knowledge of their distribution is crucial for understanding the evolution of the inflammatory process. In this study, we used rat adjuvant-induced arthritis (AIA), a model for RA, to define the temporospatial expression of chemokine receptors. METHODS: ST from rats with AIA was immunostained, the percentage of cells expressing each receptor was determined, and findings were correlated with levels of inflammation. Chemokine receptor expression was evaluated on rat macrophages in vitro. RESULTS: CCR1, a receptor for macrophage inflammatory protein 1alpha (MIP-1alpha)/CCL3 and RANTES/CCL5, exhibited high constitutive expression on macrophages in AIA. CCR5, binding MIP-1alpha/CCL3 and RANTES/CCL5, was up-regulated on ST macrophages during the course of AIA, correlating with macrophage expression of CCR2, a receptor for monocyte chemoattractant protein 1/CCL2. Endothelial cell (EC) CCR2 was down-regulated as arthritis progressed, inversely correlating with inflammation. CCR3, another RANTES/CCL5 receptor, was constitutively high on macrophages in vivo and in vitro, with down-regulation during AIA. CXCR4, a receptor for stromal cell-derived factor 1/CXCL12), was prominently up-regulated on ECs, preceding the peak of inflammation. CONCLUSION: These findings show that 1) constitutive expression of CCR1 on macrophages remains high during AIA; 2) CCR2 and CCR3 may play a role in initial recruitment of leukocytes to ST in AIA; 3) macrophage expression of CCR2 and CCR5 may be important for sustaining inflammatory changes; and 4) EC CXCR4 may be a harbinger of inflammatory changes. Our results may help guide chemokine receptor blockade-targeting treatment strategies in inflammatory arthritis.     

Potential biomarkers of osteonecrosis in Gaucher disease

BackgroundTo investigate the relationship between chemokines and cytokines and osteonecrosis in Gaucher disease, we conducted multiplex assays in a cohort of 100 adult patients.MethodsMean age was 45 years (18–86); 92 Gaucher patients received imiglucerase (median duration 8 years (2–18)). Forty-three had experienced osteonecrosis (ON), and eight had ON despite enzyme therapy. Serum cytokines/chemokines were determined by fluorimetric bead arrays in samples from Gaucher patients and healthy volunteers (10 males and 10 females). Intra-assay and inter-assay coefficients of variation were 2%–9.8% and 5.6%–15%, respectively.ResultsVEGF and CCL5/RANTES did not differ between Gaucher and control samples. Concentrations of CCL3/MIP-1α, CCL4/MIP-1β, CCL2/MCP-1, CXCL8/IL-8, IL-1ra and CCL18/PARC were elevated in Gaucher patients (p < 0.05 for each). Median CCL4/MIP-1β, CXCL8/IL-8, CCL5/RANTES and CCL18/PARC concentrations were greater in the 43 osteonecrosis patients (88.6 pg/mL, 30.5 pg/mL, 89.6 ng/mL and 434 ng/mL, respectively) compared with the 57 patients who had no evidence of osteonecrosis (medians of 59.4, 13.3, 62.7 and 283, respectively, p < 0.05). Moreover, the eight patients with ON despite imiglucerase had median concentrations of CCL3/MIP-1α, CCL4/MIP-1β, CXCL8/IL-8, CCL5/RANTES and CCL18/PARC (73.2, 120.9, 36.3 pg/mL, 105 and 767 ng/mL, respectively), which significantly exceeded the values in 84 patients now free of ON (52.3, 71.2, 16.5 pg/mL, 69.5 and 315 ng/mL, respectively, p < 0.05). Treatment exposures were similar.ConclusionNumerous serum cytokines are elevated in Gaucher disease. CCL18/PARC, CCL3/MIP-1α, CCL4/MIP-1β, CCL5/RANTES and CXCL8/IL-8 are potential biomarkers of osteonecrosis and may allow prediction of this disabling complication.     

狼疮易感基因IFIT1调控巨噬细胞趋化因子表达初探

目的 研究IFIT1对小鼠巨噬细胞系趋化因子产生的影响,探讨其在系统性红斑狼疮(SLE)中的致病机制.方法 电转染法在RAW264.7细胞系中瞬时转染IFIT1,实时荧光定量聚合酶链反应(realtime-PCR)检测IFIT1过表达对该细胞趋化因子巨噬细胞炎症蛋白(MIP)-1α、RANTES、CCL9、CX-CL2和IP-10表达的影响;同时检测NZB/NZW F1小鼠肾组织上述趋化因子表达水平.结果 瞬时转染musIFIT1的RAW264.7小鼠巨噬细胞上述趋化因子表达水平均较对照细胞明显增高,LPS刺激后4 h及24 h表达进一步增高.与正常对照BALB/c小鼠相比,NZB/NZW F1小鼠肾组织中上述趋化因子表达增高.结论 狼疮易感摹因IFIT1可促进巨噬细胞趋化因子MIP-1α、RANTES、CCL9、CXCL2和IP-10的表达,从而可能参与了SLE局部脏器的免疫损伤.     

Proinflammatory cytokines and chemokine production and expression by human osteoblasts isolated from patients with rheumatoid arthritis and osteoarthritis

OBJECTIVE: To evaluate whether subchondral osteoblasts (OB) are involved in the production of cytokines and chemokines in rheumatic diseases. METHODS: OB were isolated from subchondral bone of rheumatoid arthritis (RA), osteoarthritis (OA) and post-traumatic (PT) patients, cultured in vitro in the presence or absence of interleukin 1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha), and assessed for the production, immunolocalization, and mRNA expression of proinflammatory cytokines (IL-1alpha, IL-1beta, TNF-alpha) and alpha and beta chemokines [IL-8, growth related gene product (GRO-alpha), monocyte chemoattractant protein 1 (MCP-1), RANTES, and macrophage inflammatory proteins MIP-1alpha, MIP-1beta]. RESULTS: Cultured OB from different patients did not release IL-1alpha, IL-1beta, or TNF-alpha, and constitutively secreted IL-8, GRO-alpha, and MCP-1, while RANTES, MIP-1alpha, MIP-1beta were undetectable or near the lower level of sensitivity of the immunoenzymatic assay. GRO-alpha was significantly higher in RA than in OA and PT patients. IL-1beta and TNF-alpha alone or in combination strongly stimulated chemokine release by OB. Only RANTES production was not increased by the combination of the 2 cytokines. IL-1alpha, IL-1beta, and TNF-alpha were expressed as cytoplasmic proteins and were not secreted by OB even after stimulation. CONCLUSION: OB from subchondral bone release chemokines that could be involved in the mechanisms that directly or indirectly cause bone remodelling and cartilage destruction.     

Higher mRNA levels of chemokines and cytokines associated with macrophage activation in erythema migrans skin lesions in patients from the United States than in patients from Austria with Lyme borreliosis.

BACKGROUND: Erythema migrans (EM) is caused primarily by Borrelia afzelii in Europe and solely by Borrelia burgdorferi in the United States. B. burgdorferi infection in the United States has previously been associated with faster expansion of EM lesions and with more associated symptoms, compared with B. afzelii infection in Europe. However, reasons for these differences are not yet known. METHODS: We determined the Borrelia species infecting 67 US or Austrian patients with EM. The clinical pictures and chemokine and cytokine mRNA levels in lesional skin were then compared in the 19 B. burgdorferi-infected US patients and the 37 B. afzelii-infected Austrian patients, the 2 largest groups. RESULTS: The 19 B. burgdorferi-infected US patients had faster-expanding EM lesions and a median of 4 associated signs and symptoms, whereas the 37 B. afzelii-infected Austrian patients had slower-expanding lesions and usually did not experience associated symptoms. Compared with the EM lesions of B. afzelii-infected Austrian patients, those of B. burgdorferi-infected US patients had significantly higher mRNA levels of chemokines associated with activation of macrophages, including chemoattractants for neutrophils (CXCL1), macrophages (CCL3 and CCL4), and T helper 1 cells (CXCL9, CXCL10, and CXCL11). In addition, compared with the EM lesions of Austrian patients, the EM lesions of US patients tended to have higher mRNA levels of the macrophage-associated proinflammatory cytokines interleukin 1beta and tumor necrosis factor alpha, and they had significantly higher mRNA expression of the antiinflammatory cytokines interleukin 10 and transforming growth factor beta. CONCLUSIONS: The EM lesions of B. burgdorferi-infected US patients expanded faster, were associated with more symptoms, and had higher mRNA levels of macrophage-associated chemokines and cytokines than did the EM lesions of B. afzelii-infected Austrian patients.     

Reduction of chemokine levels and leukocyte traffic to joints by tumor necrosis factor alpha blockade in patients with rheumatoid arthritis

OBJECTIVE: To verify the hypothesis that in rheumatoid arthritis (RA), tumor necrosis factor alpha (TNFalpha) plays a critical role in regulating leukocyte trafficking and chemokine levels. METHODS: Ten patients with longstanding RA received a single 10 mg/kg infusion of anti-TNFalpha monoclonal antibody (cA2). The articular localization of autologous granulocytes, separated in vitro and labeled with 111In, was studied by analysis of gamma-camera images both before and 2 weeks after treatment. At the same sequential time points, synovial biopsy samples were assessed for infiltrating CD3+ T cells, CD22+ B cells, and CD68+ macrophages. Synovial tissue expression of the chemokines interleukin-8 (IL-8), monocyte chemotactic protein 1 (MCP-1), macrophage inflammatory protein 1alpha (MIP-1alpha), MIP-1beta, Groalpha, and RANTES was also determined. Serum IL-8 and MCP-1 concentrations were measured by enzyme-linked immunosorbent assay. RESULTS: Anti-TNFalpha therapy in RA significantly reduced 111In-labeled granulocyte migration into affected joints. There was a simultaneous and significant reduction in the numbers of infiltrating synovial CD3+ T cells, CD22+ B cells, and CD68+ macrophages and in the expression of IL-8 and MCP-1, with a trend toward a reduction in serum concentrations of these chemokines. CONCLUSION: TNFalpha blockade reduces synovial expression of the chemokines IL-8 and MCP-1 and diminishes inflammatory cell migration into RA joints.