MCP-1 receptor binding affinity is up-regulated by pre-stimulation with MCP-1 in an actin polymerization-dependent manner

Monocyte chemoattractant protein-1 (MCP-1) induces monocyte chemotaxis via interaction with the MCP-1 receptor CCR2. We found that MCP-1 binding to monocytic THP-1 cells was increased by pre-treatment with MCP-1. The amount of CCR2 mRNA and the cell-surface expression of CCR2 were not affected by MCP-1 stimuli. In contrast, the MCP-1-treated THP-1 cells showed a sixfold increase in MCP-1 binding affinity compared with untreated cells. MCP-1 binding to CCR2B-transfected HEK-293 cells was also enhanced by pre-treatment with MCP-1, and MCP-1 binding affinity increased by sixfold. In both cell lines, the enhancement of MCP-1 binding by stimulation with MCP-1 was blocked by cytochalasin D, an inhibitor of actin polymerization. This effect of pre-treatment with MCP-1 is insensitive to pertussis toxin and partially blocked by U73122, an inhibitor of phospholipase C. These results demonstrate that the MCP-1 receptor binding affinity is up-regulated by MCP-1 stimuli in an actin polymerization-dependent manner.     

RANTES, MCP-1, CCR2, CCR5, CXCR1 and CXCR4 gene polymorphisms are not associated with the outcome of hepatitis B virus infection: results from a large scale single ethnic population

Recovery from hepatitis B virus (HBV) infection depends on the cellular immune responses. Chemokines and their receptors play significant roles in immune defense. This study was undertaken to investigate the association between HBV infection and single nucleotide polymorphisms (SNPs) of genes for the chemokines and their receptors. Between March 2002 and February 2004, a total of 957 single ethnic Korean patients were enrolled into two different groups; "HBV clearance group" (n=350), who have recovered from HBV infection, and "HBV persistence group" (n=607), who were repeatedly HBsAg-positive. The HBV persistence group was subdivided into "inactive carrier" and "HBV progression group (chronic hepatitis and cirrhosis)". We assessed polymorphisms in regulated and normal T-cell expressed and secreted (RANTES) at position -403, monocyte chemoattractant protein-1 (MCP-1) at position -2518, CCR2 V64I, CCR5 -2459, CXCR1 S276T and CXCR4 I138I using single primer extension assay. Genotype distributions of the "HBV clearance versus persistence group" and "inactive carrier versus HBV progression group" were compared. On the basis of unconditional logistic regression analysis with adjustment for age and sex, no statistically significant association with susceptibility to persistent HBV infection was observed with RANTES -403, MCP-1 -2518, CCR2 V64I, CCR5 -2459, CXCR1 S276T, and CXCR4 I138I polymorphisms. In addition, no association of analyzed SNPs with HBV disease progression was found.     

An associated molecule, p64, with high-affinity interleukin 2 receptor

TU11 mAb specific for the human interleukin-2 receptor (IL-2R) beta-chain, p75, co-precipitated two molecules, p64 and p55, with the beta-chain in the lysates of cells bearing the high-affinity IL-2R. The co-precipitation was detected in the presence of IL-2 even in the absence of a chemical cross-linker. H-48 mAb specific for the IL-2R alpha-chain completely pre-absorbed p64 as well as p55 and partially pre-absorbed the beta-chain from the lysates. The co-precipitation was also detected in phytohemagglutinin-stimulated normal peripheral blood lymphocytes, which express the high-affinity IL-2R, but not in the cell line cells bearing only the low-affinity IL-2R. The peptide maps indicate that p64 is a molecule distinct from both the alpha- and beta-chains, and that p55 is identical to the alpha-chain. These findings suggest that p64, along with the alpha- and beta-chains, is a component of the high affinity IL-2R complex, and we have tentatively named it the gamma-chain of IL-2R.     

Elevated monocyte chemotactic proteins 1, 2, and 3 in pulmonary alveolar proteinosis are associated with chemokine receptor suppression

Pulmonary alveolar proteinosis (PAP) is a rare autoimmune lung disease characterized by abnormal surfactant accumulation within alveolar macrophages, and circulating auto-antibodies against granulocyte-macrophage colony stimulating factor (GM-CSF) resulting in functional GM-CSF deficiency. Monocyte/macrophage chemotactic protein-1 (MCP-1) is elevated in PAP, suggesting association with the pathophysiology. Because PAP has been associated with inflammatory pulmonary changes, we hypothesized that other MCP family chemokines would be present and that Chemokine Chemotaxis Receptor 2 (CCR2) would be elevated on PAP mononuclear cells. Here we show for the first time that MCP-2 and MCP-3, like MCP-1, are highly elevated in PAP. We also confirm that PAP alveolar macrophages and not epithelial cells produce MCP-1, and that MCP-1 from PAP lung has functional chemoattractant activity. Surprisingly, CCR2 expression is diminished in PAP lymphocytes and alveolar macrophages compared to controls. Further, MCP-1 from PAP lung suppresses CCR2 expression in vitro, suggesting that in PAP, MCP-1 participates in an autocrine regulatory network in vivo.     

Association of MCP-1 and CCR2 polymorphisms with the risk of late acute rejection after renal transplantation in Korean patients

Among the factors modulating transplant rejection, chemokines and their respective receptors deserve special attention. Increased expression of monocyte chemoattractant protein-1 (MCP-1) and its corresponding receptor (chemokine receptor-2, CCR2) has been implicated in renal transplant rejection. To determine the impact of the MCP-1-2518G and CCR2-64I genotypes on renal allograft function, 167 Korean patients who underwent transplantation over a 25-year period were evaluated. Genomic DNA was genotyped using polymerase chain reaction followed by restriction fragment length polymorphism analysis. Fifty-five (32.9%) patients were homozygous for the MCP-1-2518G polymorphism. Nine (5.4%) patients were homozygous for the CCR2-64I polymorphism. None of the investigated polymorphism showed a significant shift in long-term allograft survival. However, a significant increase was noted for the risk of late acute rejection in recipients who were homozygous for the MCP-1-2518G polymorphism (OR, 2.600; 95% CI, 1.125-6.012; P = 0.022). There was also an association between the MCP-1-2518G/G genotype and the number of late acute rejection episodes (P = 0.024). Although there was no difference in the incidence of rejection among recipients stratified by the CCR2-V64I genotype, recipients with the CCR2-V64I GG genotype in combination with the MCP-1-2518G/G genotype had a significantly higher risk of acute or late acute rejection among the receptor-ligand combinations (P = 0.006, P = 0.008, respectively). The MCP-1 variant may be a marker for risk of late acute rejection in Korean patients.     

A review on structural,non-structural,and accessory proteins of SARS-CoV-2: Highlighting drug target sites

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of COVID-19, is a highly transmittable and pathogenic human coronavirus that first emerged in China in December 2019. The unprecedented outbreak of SARS-CoV-2 devastated human health within a short time leading to a global public health emergency. A detailed understanding of the viral proteins including their structural characteristics and virulence mechanism on human health is very crucial for developing vaccines and therapeutics. To date, over 1800 structures of non-structural, structural, and accessory proteins of SARS-CoV-2 are determined by cryo-electron microscopy, X-ray crystallography, and NMR spectroscopy. Designing therapeutics to target the viral proteins has several benefits since they could be highly specific against the virus while maintaining minimal detrimental effects on humans. However, for ongoing and future research on SARS-CoV-2, summarizing all the viral proteins and their detailed structural information is crucial. In this review, we compile comprehensive information on viral structural, non-structural, and accessory proteins structures with their binding and catalytic sites, different domain and motifs, and potential drug target sites to assist chemists, biologists, and clinicians finding necessary details for fundamental and therapeutic research.     

Chemotaxis of human tonsil B lymphocytes to CC chemokine receptor (CCR) 1, CCR2 and CCR4 ligands is restricted to non-germinal center cells

We have investigated the effects of nine CC chemokines, i.e. macrophage inflammatory protein (MIP)-1alpha/CCL3, MIP-1beta/CCL4, MIP-3alpha/CCL20, MIP-5/CCL15, monocyte chemotactic protein (MCP)-1/CCL2, MCP-2/CCL8, MCP-3/CCL7, eotaxin/CCL11 and macrophage-derived chemokine (MDC)/CCL22 on the locomotion of human tonsil B lymphocytes and their subsets. Upon isolation, B cells were poorly responsive, but, following short-term culture, they displayed statistically significant chemotactic responses (P < 0.001) to MIP-1alpha, MIP-5, MCP-1, MCP-2, MCP-3 and MDC. CC chemokine receptor (CCR) 1 to CCR6 were up-regulated after culture. MIP-1beta, MIP-3alpha and eotaxin did not stimulate B cell migration. Scattered information is available on B cell subset responses to chemokines. Therefore, we investigated the effects of MIP-1alpha, MIP-5, MCP-1, MCP-2, MCP-3 and MDC on the in vitro locomotion of non-germinal center (GC) (CD38(-)) and GC (CD38(+)) B cells. All chemokines enhanced significantly (P < 0.001) the migration of the former, but not of the latter, cells. CCR1, CCR2 and CCR4 were detected by flow cytometry on non-GC (i.e. naive and memory) B cells, whereas they were absent (CCR1 and CCR2) or poorly expressed (CCR4) on GC B cells.     

Polymorphism in the gene regulatory region of MCP-1 is associated with asthma susceptibility and severity.

BACKGROUND: Chemokines play an important role in the pathophysiology of asthma and allergy. Recently, polymorphisms in the gene regulatory region of monocyte chemoattractant protein 1 (MCP-1) and in the promoter region of RANTES have been found; these polymorphisms increase the expression of the chemokines. OBJECTIVE: We investigated whether the presence of the polymorphisms was associated with atopy or asthma and whether these alleles influenced the severity of asthma in affected individuals. METHODS: Three groups of subjects-160 children with asthma (disease severity being classified according to the Global Initiative for Asthma guidelines, modified for children), 151 children with nonasthmatic but allergic phenotype, and 303 children without allergic or asthmatic disorders-were screened with a PCR-based assay for genotyping. RESULTS: The frequency of the -2518G polymorphism in the gene regulatory region of MCP-1 was significantly higher in asthmatic children than in controls (P <.001; odds ratio [OR] = 2.0 [1.4-2.6]) and nonasthmatic atopic children (P <.001; OR = 2.0 [1.4-2.9]). The MCP-1 G/G genotype correlated with asthma severity. In asthmatic children, the MCP-1 -2518G allele was also associated with an increased blood eosinophil level. The promoter polymorphisms in the RANTES gene did not have a detectable effect on the susceptibility to asthma or allergy or on the blood eosinophil count. CONCLUSION: In this cohort of children, there are associations between carrying G at -2518 of the MCP-1 gene regulatory region and the presence of asthma as well as between asthma severity and homozygosity for the G allele. In asthmatic children, the MCP-1 -2518G polymorphism correlated with increased eosinophil levels. This variant of MCP-1 might belong to the predictor gene set for asthma.     

Distribution of HIV/AIDS protective SDF1, CCR5 and CCR2 gene variants within Cretan population.

An interesting finding in the epidemiology of human immunodeficiency virus (HIV) infection is that certain mutations in genes coding for chemokine receptors and their ligands may confer resistance to HIV-1 infection and/or AIDS progression. The mutations most frequently studied are the CCR5-delta32, CCR2-64I and SDF1-3'A. We examined the frequency of the above polymorphisms within the Cretan population, evaluating their contribution to a protective genetic background against HIV infection and progression. Two hundred blood samples were recruited at random among prospective blood donors from Crete. Genotyping was initially performed by polymerase chain reaction (PCR) analysis. CCR2 and SDF-1 PCR-amplified genomic regions were further subjected to restriction fragment length polymorphism (RFLP) analysis for genotype determination. The CCR5-delta32 allele frequency among our study group was 3.25%, although no respective homozygous samples were detected. The screening for the CCR2-64I polymorphism yielded 39 heterozygous (19.5%) and 4 homozygous (2%) subjects, revealing a CCR2-64I allele frequency of 11.75%. Among our 200 PCR-RFLP analysed samples, 73 (36.5%) were found heterozygous and 23 (11.5%) homozygous for the SDF1-3'A mutant variant. The allele frequency of the above polymorphism reached 29.75%. The frequency of the CCR5-delta32 allele among our study population seems to be remarkably lower compared to previously reported frequencies in other Caucasian groups. However, the SDF1-3'A allele frequency shows significantly higher distribution profiles within our study group compared to those observed in other Caucasian-European populations. The indicated difference could be attributed to the increased homogeneity of our population, which is well balanced and dispersed over a small geographical area. Since this polymorphism is related with delayed progression from HIV infection to AIDS, it could be used for prognostic genotyping in HIV infected Cretan individuals.     

Severe asthma is associated with a loss of LX4, an endogenous anti-inflammatory compound

BACKGROUND: Lipoxins and 15-epi-lipoxins are lipid mediators that modulate leukocyte trafficking and promote the inflammation resolution. They are produced by different enzymatic pathways. Patients with severe asthma present ongoing airway inflammation despite chronic long-term treatment including oral glucocorticoids. OBJECTIVES: The aim of this study was to assess the presence of proinflammatory and anti-inflammatory mediators in the supernatants of induced sputum. METHODS: Induced sputum supernatants were collected from 10 normal subjects; 12 subjects with mild, 15 with moderate, and 24 with severe asthma; and 13 patients with chronic obstructive pulmonary disease. First, we validated the measurements of IL-8, leukotriene B 4 , lipoxin A 4 , and 15-epi-lipoxin A 4 in these samples. Then we measured these mediators by using immunoenzymatic methods. RESULTS: IL-8 levels were highly increased in patients with severe asthma ( P < .0001), and leukotriene B 4 levels were significantly increased in patients with severe asthma and patients with chronic obstructive pulmonary disease. Lipoxin A 4 was significantly increased in the supernatant obtained from patients with mild asthma ( P < .0001), whereas 15-epi-lipoxin A 4 levels were higher in patients with severe asthma ( P = .05). More interestingly, we found a positive correlation between the level of lipoxin A 4 and IL-8 in patients with mild asthma. CONCLUSION: These results indicate that induced sputum is a suitable method to assess lipoxin and 15-epi-lipoxin measurements in bronchi. The mechanisms involved in the synthesis of these 2 eicosanoid mediators would be helpful to understand better the imbalance between proinflammatory and anti-inflammatory mediators occurring in severe asthma. Lipoxin production involves interaction between lipoxygenases, whereas 15-epi-lipoxin production might involve CytP450 activity.     

Expression of monocyte chemotactic protein (MCP)-1, MCP-2, and MCP-3 by human airway smooth-muscle cells. Modulation by corticosteroids and T-helper 2 cytokines.

We have demonstrated that, in addition to their contractile function, human airway smooth-muscle cells (HASMC) are able to express and to secrete chemokines of the monocyte chemotactic protein (MCP)/ eotaxin subfamily. This group of chemokines is believed to play a fundamental role in the development of allergic airway diseases such as asthma. The expression levels of MCP (MCP-1, -2, and -3) messenger RNA (mRNA) were compared with those of regulated on activation, normal T cells expressed and secreted (RANTES) mRNA in HASMC in culture. HASMC express MCP and RANTES mRNA after stimulation with interleukin (IL)-1beta, tumor necrosis factor-alpha, and interferon-gamma. MCP mRNA was maximal at 8 h, whereas RANTES mRNA expression was delayed to 24 h after stimulation. Further, significant differences were observed in the induction patterns of MCP and RANTES mRNA expression after stimulation with the individual cytokines. Dexamethasone (DEX) significantly inhibited cytokine-induced accumulation of MCP and RANTES mRNA, in contrast to IL-4, IL-10, and IL-13, which had no inhibitory effect on cytokine-induced chemokine expression. The cytokine-induced MCP mRNA expression in HASMC was associated with MCP release, which was inhibited by DEX and post-translationally by IL-4. HASMC can actively participate in the pathogenesis of asthma by the expression and release of chemokines, which are likely to play a critical role in the generation and regulation of the inflammatory response characteristic of allergic airway diseases.     

Tachykinin receptor 1 variants associated with aggression in suicidal behavior.

Substance P is involved in the modulation of depression, anxiety, and suicidal-related behaviors. We studied gene variants of Tachykinin Receptor 1 (TACR1-rs3771810, rs3771825, rs726506, rs1477157) in 167 German suicide attempters (affective spectrum n = 107, schizophrenia spectrum n = 35, borderline personality disorder n = 25), 92 Caucasian individuals who committed suicide and 312 German healthy subjects. Single markers and haplotype analysis in relation to suicidal behaviors (suicide attempters/completers) did not reveal any significant association. The rarest rs3771825 T allele however showed a marginal association with higher Reactive Aggression scores on the Questionnaire for Measuring Factors of Aggression (FAF) (F = 9.86, df = 1; P = 0.0017). Haplotype analyses confirmed the finding. Violence or impulsivity of suicide attempt and State-Trait Anger Expression Inventory (STAXI) scores were not associated with gene variants. In conclusion, our study suggests that TACR1 gene variants have no major influence on suicidal behavior but may modulate aggression features.     

血清S1OOB,MCP-1,COX-2及hs-CRP与急性冠脉综合征的相关性分析

目的 观察不同类型急性冠状动脉综合征患者血清S100B、MCP-1、COX2和高敏C反应蛋白(hs-CRP)等因子的表达水平,探讨其与不同类型冠脉综合征的相关性以及诊断意义.方法 选择急性冠状动脉综合征患者134例,根据诊断分为急性心肌梗死(AMI)组55例,不稳定性心绞痛(UAP)组69例,另选取61例稳定性心绞痛患者作为SAP组,及健康体检者45名为健康对照组.运用酶联免疫吸附试验(ELISA法)测定血清S100B、MCP-1、COX-2及hs-CRP水平.结果 AMI组和UAP组S100B、MCP-l、COX2和hs-CRP等因子的表达水平明显高于健康对照组;SAP组MCP-1,hs-CRP明显高于健康对照组,差异有统计学意义(P＜0.01),COX2水平与健康对照组差异无统计学意义.AMI组和UAP组S100B、MCP-1、COX2和hs-CRP水平明显高于SAP组,差异有统计学意义(P＜0.05).结论 S100B、COX2可作为急性冠状动脉综合征斑块稳定性病变严重程度的预测因子,调节S100B及COX2可能成为治疗冠脉综合症的潜在靶点.     

Diseases associated with HTLV-I: virus, IL-2 receptor dysregulation and redox regulation.

HTLV-I, the etiological agent in adult T-cell leukemia, has also been strongly implicated in a number of non-neoplastic T-cell-associated diseases. Here, Junji Yodoi and Takashi Uchiyama review these associations and focus on the emerging concepts of IL-2R dysregulation and redox regulation by adult T-cell leukemia-derived factor in the pathogenesis of HTLV-I-related diseases.     

Treatment with bindarit, an inhibitor of MCP-1 synthesis, protects mice against trinitrobenzene sulfonic acid-induced colitis

OBJECTIVE: Chemokines play a fundamental role in trafficking and activation of leukocytes in colonic inflammation. We investigated the ability of bindarit, an inhibitor of monocyte chemoattractant protein-1 (MCP-1/CCL2) synthesis, to inhibit chemokine production by human intestinal epithelial cells (HT-29) and its effect in trinitro-benzene sulfonic acid (TNBS)-induced colitis in mice.MATERIALS AND METHODS: HT-29 cells were incubated with bindarit in the presence of TNF-alpha/IFN-gamma and 24 h later supernatants were collected for MCP-1, IL-8 and RANTES measurement. A 1 mg enema of TNBS was given to BALB/c mice, and bindarit (100 mg/kg) was orally administered twice daily starting from two days before colitis induction. Weight loss, histology, and MCP-1 level and myeloperoxidase (MPO) activity in colon extracts were assessed.RESULTS: In HT-29 cells, bindarit concentration-dependently and selectively inhibited MCP-1 secretion (as well as mRNA expression) primed by TNF-alpha/IFN-gamma. Moreover treatment with bindarit reduced clinical and histopathological severity of TNBS-induced colitis. These effects were associated with significant inhibition of MCP-1 and MPO in colon extracts.CONCLUSIONS: Bindarit exhibits a potent bioactivity in reducing leukocyte infiltration, down-regulating MCP-1 synthesis, and preventing the development of severe colitis in a mice model of TNBS-induced colitis. These observations suggest a potential use of MCP-1 synthesis blockers in intestinal inflammation in humans.     

Lack of association of human chemokine receptor gene polymorphisms CCR2-64I and CCR5-Delta32 with autoimmune Addison's disease.

The attraction of leukocytes to tissues is essential for inflammation and the initiation of the autoimmune reaction. The process is controlled by chemokines, which are chemotactic cytokines. We investigated whether human chemokine receptor gene polymorphisms, namely CCR5-Delta32 and CCR2-64I, are associated with susceptibility to autoimmune Addison's disease. Genotyping was performed in 56 patients and 127 healthy controls by a new method using pyrosequencing for CCR2-64I and by polymerase chain reaction and detecting gel for CCR5-Delta32. None of the CCR2 or CCR5 alleles was found to be associated, either positively or negatively, with disease risk. Our results indicate that the CCR2-64I and CCR5-Delta32 gene polymorphisms do not play a major role in conferring genetic risk for, and/or protection against, autoimmune Addison's disease.