The yin-yang of long pentraxin PTX3 in inflammation and immunity

Pentraxins are a family of multimeric proteins characterized by the presence of a pentraxin signature in their C-terminus region. Based on the primary structure, pentraxins are divided into short and long pentraxin: C-reactive protein (CRP) is the prototype of the short pentraxin subfamily while pentraxin 3 (PTX3) is the prototypic long pentraxin. Despite these two molecules exert similar fundamental actions in the regulation of innate immune and inflammatory responses, several differences exist between CRP and PTX3, including gene organization, protein oligomerization and expression pattern. The pathophysiological roles of PTX3 have been investigated using genetically modified mice since PTX3 gene organization and regulation are well conserved between mouse and human. Such in vivo studies figured out that PTX3 mainly have host-protective effects, even if it could also exert negative effects under certain pathophysiologic conditions. Here we will review the general properties of CRP and PTX3, emphasizing the differences between the two molecules and the regulatory functions exerted by PTX3 in innate immunity and inflammation.     

Toll-like receptor 3 gene polymorphisms in South African Blacks with type 1 diabetes

Type 1 diabetes is the consequence of exposure of genetically susceptible individuals to specific environmental precipitants. The innate immune system provides the initial response to exogenous antigen and links with the adaptive immune system. The aim of this study was to assess the role of polymorphisms occurring in the cytoplasmic region of toll-like receptor (TLR) 3 gene and immediate 5' sequence, in subjects of Zulu descent with type 1 diabetes in KwaZulu-Natal, South Africa. Seventy-nine subjects with type 1 diabetes and 74 healthy normal glucose tolerant gender-matched control subjects were studied. Parts of exon 4 and exon 3/intron 3 of the TLR3 gene were studied by polymerase chain reaction, direct sequencing and restriction enzyme digestion with Bts 1. Of the nine polymorphisms studied, a significant association with type 1 diabetes was found for the major allele in the 2593 C/T polymorphism and for the minor alleles in the 2642 C/A and 2690 A/G polymorphisms, which were found to be in complete linkage disequilibrium. Correction of the P-values for the number of alleles studied, however, rendered the results no longer significant. These results suggest that polymorphisms in the TLR3 gene, which is part of the innate immune system, may be associated with type 1 diabetes in this population.     

The role of the intestinal microbiota in type 1 diabetes

The digestive tract hosts trillions of bacteria that interact with the immune system and can influence the balance between pro-inflammatory and regulatory immune responses. Recent studies suggest that alterations in the composition of the intestinal microbiota may be linked with the development of type 1 diabetes (T1D). Data from the biobreeding diabetes prone (BBDP) and the LEW1.WR1 models of T1D support the hypothesis that intestinal bacteria may be involved in early disease mechanisms. The data indicate that cross-talk between the gut microbiota and the innate immune system may be involved in islet destruction. Whether a causal link between intestinal microbiota and T1D exists, the identity of the bacteria and the mechanism whereby they promote the disease remain to be examined. A better understanding of the interplay between microbes and innate immune pathways in early disease stages holds promise for the design of immune interventions and disease prevention in genetically susceptible individuals.     

Killer cell immunoglobulin-like receptor genotypes in Japanese patients with type 1 diabetes

We investigated killer cell immunoglobulin-like receptor (KIR) genotypes in 92 patients with young-onset type 1 diabetes mellitus (YT1DM: < or =35 years old), 112 patients with adult-onset type 1 diabetes mellitus (AT1DM: >35 years old) and 240 control subjects. There were no differences in the frequency of KIR genotypes between controls and all the patients with T1DM or patients grouped according to age at onset of the disorder. However, when the subjects were classified into three groups according to combinations of the presence or absence of KIR3DS1/KIR3DL1 and its ligand human leukocyte antigen (HLA)-Bw4, or KIR2DL1 and its ligand HLA-C group 2, the genotype distribution was significantly different between the patients with AT1DM and controls [chi(2)= 5.993, 2 degrees of freedom (d.f.), P= 0.0500]. These data suggest that KIR polymorphisms may be associated with the age at onset of T1DM.     

Biochemical and functional characterization of the interaction between pentraxin 3 and C1q

Pentraxin 3 (PTX3) is a recently characterized member of the pentraxin family of acute-phase proteins produced during inflammation. Classical short pentraxins, C-reactive protein, and serum amyloid P component can bind to C1q and thereby activate the classical complement pathway. Since PTX3 can also bind C1q, the present study was designed to define the interaction between PTX3 and C1q and to examine the functional consequences of this interaction. A dose-dependent binding of both C1q and the C1 complex to PTX3 was observed. Experiments with recombinant globular head domains of human C1q A, B, and C chains indicated that C1q interacts with PTX3 via its globular head region. Binding of C1q to immobilized PTX3 induced activation of the classical complement pathway as assessed by C4 deposition. Furthermore, PTX3 enhanced C1q binding and complement activation on apoptotic cells. However, in the fluid-phase, pre-incubation of PTX3 with C1q resulted in inhibition of complement activation by blocking the interaction of C1q with immunoglobulins. These results indicate that PTX3 can both inhibit and activate the classical complement pathway by binding C1q, depending on the way it is presented. PTX3 may therefore be involved in the regulation of the innate immune response.     

Differences in MBL levels between juvenile patients newly diagnosed with type 1 diabetes and their healthy siblings

The incidence of type 1 diabetes (T1D) has during the last few decades been increasing in children and juveniles. Multi-factorial courses combining genetic disposition and environmental factors might be in play, and through the years, there has been a mounting interest in the innate immune system's role in the development of T1D.     

Crystallization of oral fluid components in patients with type 1 diabetes mellitus

We systematized and described morphological criteria characterizing crystalline aggregates in mixed saliva from patients with type 1 diabetes mellitus.__________This revised version was published online in August 2005 with the addition of the issue titleTranslated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 139, No. 1, pp. 22–24, January, 2005     

正五聚蛋白 3在炎症及自身免疫中的作用

 PTX3(Pentraxin 3)作为一种可溶性模式识别受体,参与了免疫防御、炎症反应、细胞凋亡、血管重塑、女性生殖生育及血管内皮损伤等多种生理及病理效应。并可作为临床检测自身免疫性疾病中组织损伤,炎症状态严重性和活动性的一项敏感的生物学标记。其具体的作用机制仍然不明。PTX3在多数情况下,限制炎症及自身免疫的发生发展,而起到保护性效应。     

Low programmed cell death‐1 (PD‐1) expression in peripheral CD4+ T cells in Japanese patients with autoimmune type 1 diabetes

Programmed cell death‐1 (PD‐1) is a co‐stimulatory molecule that inhibits T cell proliferation. We aimed to clarify PD‐1 expression in CD4⁺ T cells and the association between PD‐1 expression and the 7785C/T polymorphism of PDCD1, with a focus on the two subtypes of type 1 diabetes, type 1A diabetes (T1AD) and fulminant type 1 diabetes (FT1D), in the Japanese population. We examined 22 patients with T1AD, 15 with FT1D, 19 with type 2 diabetes (T2D) and 29 healthy control (HC) subjects. Fluorescence‐activated cell sorting (FACS) and real‐time PCR were utilized to analyse PD‐1 expression quantitatively. Genotyping of 7785C/T in PDCD1 was performed using the TaqMan method in a total of 63 subjects (21 with T1AD, 15 with FT1D and 27 HC). FACS revealed a significant reduction in PD‐1 expression in CD4⁺ T cells in patients with T1AD (mean: 4·2 vs. 6·0% in FT1D, P = 0·0450; vs. 5·8% in T2D, P = 0·0098; vs. 6·0% in HC, P = 0·0018). PD‐1 mRNA expression in CD4⁺ T cells was also significantly lower in patients with T1AD than in the HC subjects. Of the 63 subjects, PD‐1 expression was significantly lower in individuals with the 7785C/C genotype than in those with the C/T and T/T genotypes (mean: 4·1 vs. 5·9%, P = 0·0016). Our results indicate that lower PD‐1 expression in CD4⁺ T‐cells might contribute to the development of T1AD through T cell activation.     

用核酸序列测定1型糖尿病HLA-DPB1和DQB1第2外显子基因

目的 研究山东省汉族1型糖尿病与HLA－DPB1和HLA－DQB1等位基因的相关性。方法 采用基于核酸序列测定的基因分型技术对52例1型糖尿病患者及38例正常对照进行了DPB1和DQB1基因分析。结果 DPB1＊2201（P＜0．01）和DQB1＊0201（P＜0．01）、＊0303（P＜0．05）及＊0604（P＜0．05）等位基因频率在糖尿病患者组显著高于对照组,而PB1＊0402（P＜0．01）和DQB1＊0301（P＜0．01）等位基因在糖尿病患者组显著低于对照组。结论 DPB1＊2201和DQB1＊0201、＊0303及＊0604等位基因可能是山东省汉族1型糖尿病的易感性等位基因,而DPB1＊0402和DQB1＊0301等位基因可能是山东省汉族1型糖尿病的保护性等位基因。     

Elevated plasma levels of the long pentraxin, pentraxin 3, in severe dengue virus infections

C-reactive protein is one of the most widely used indicators of the response of acute-phase proteins. The measurement of C-reactive protein in dengue, however, is clinically not useful, because of marginally elevated levels and absent association with disease severity. The prototypic long pentraxin, pentraxin 3, is an acute phase protein that is structurally related but distinct from C-reactive protein which has proven to correlate with the severity of bacterial infection in critically ill patients. The potential involvement of pentraxin 3 in dengue and its aptitude to predict more severe disease or poor clinical outcome has not been studied previously. We therefore measured pentraxin 3 plasma levels in 44 dengue virus infected patients. Pentraxin 3 levels were strikingly higher when compared to C-reactive protein levels, with highest pentraxin 3 values observed in the first 7 days after the onset of symptoms. Median pentraxin 3 levels at admission and peak levels during follow up were higher in patients suffering from dengue shock syndrome (at admission: 119.3 ng/ml [interquartile range 61.8--188.7], peak values during follow up: 147.9 ng/ml [interquartile range 85.7--204.3]) compared to levels found in patients with dengue fever and dengue hemorrhagic fever (at admission: 59.0 ng/ml [interquartile range 28.6--100.3], P=0.040; peak values during follow up: 80.8 ng/ml [interquartile range 36.1--168.1], P=0.020). Our results indicate that pentraxin 3 seems to be a marker of infection better than C-reactive protein in dengue. The role of pentraxin 3 in the pathogenesis of dengue and its potential as an early prognostic indicator of disease severity needs further assessment.     

TIM-3 polymorphisms in type 1 diabetes families

TIM-3 is a transmembrane protein preferentially expressed on differentiated Th1 cells, which play a role in Th1-mediated diseases including type 1 diabetes. We investigated the role of the rs10515746 (A/C), rs1036199 (A/C), and rs10053538 (A/C) single nucleotide polymorphisms (SNPs) within the TIM-3 gene in 186 German type 1 diabetes families (558 individuals) and its interaction with human leukocyte antigen (HLA) high-risk haplotypes DQ2(DQA*0501-DQB*0201)-DQ8 (DQA*0301-DQB*0302). Alleles A, C, and A of the rs10515746 (A/C), rs1036199 (A/C), and rs10053538 (A/C) SNPs were found in a frequency of 20.4%, 19.0%, and 4.2%, respectively. Transmission analysis of these polymorphisms did not show any significant difference. Although in patients with HLA DQx/x (neither HLA DQ2 nor DQ8) an undertransmission of allele A (14.3% vs. 85.7%) of the rs10053538 (A/C) SNP and an overtransmission of allele A (66.7% vs. 33.3%) of the rs10515746 (A/C) SNP was observed, these associations did not remain statistically significant after correction for multiple comparisons. Although we found no association of TIM-3 with type 1 diabetes in the German population, we cannot discard a possible association in a larger size.     

A selective increase in plasma soluble vascular cell adhesion molecule-1 levels in preeclampsia.

PROBLEM: The study was conducted to determine whether altered plasma levels of soluble intercellular adhesion molecule (ICAM)-1 and soluble vascular cell adhesion molecule (VCAM)-1 are involved in the pathogenesis of preeclampsia. METHOD OF STUDY: Maternal plasma samples were collected from 20 patients with preeclampsia, 20 matched normotensive patients with uncomplicated pregnancies. and ten healthy nonpregnant women. Samples were assayed for soluble VCAM-1 and soluble ICAM-1 by specific enzyme-linked immunosorbent assay. RESULTS: Both soluble VCAM-1 and soluble ICAM-1 were detectable in the plasma of all preeclamptic, normotensive pregnant, and nonpregnant women. The mean plasma level of soluble VCAM-1 was significantly higher in preeclamptic women compared to normotensive pregnant women (1831 ng/mL +/- 534 ng/mL vs. 1254 ng/mL +/- 386 ng/mL, respectively; P < 0.05). However, the plasma level of soluble VCAM-1 was unchanged during the third-trimester of normal pregnancy compared to nonpregnant women. The mean plasma level of soluble ICAM-1 in preeclamptic and normotensive pregnant women were increased when compared to nonpregnant women. However, the mean plasma level of soluble ICAM-1 was comparable in women with preeclampsia and normotensive pregnancy. CONCLUSIONS: The selective increased plasma levels of soluble VCAM-1 in patients with preeclampsia provide evidence for endothelial activation and suggest distinct pathways for neutrophil and endothelial activation in preeclampsia.     

PPP1R3基因3′端非翻译区5 bp缺失/插入多态性与2型糖尿病相关性研究

目的　研究 1型蛋白磷酸酶骨骼肌特异糖原靶向调节亚单位 (PPP1R3)基因 3′-非翻译区 5 bp缺失 /插入 (deletion/insertion,D/I)多态性与 2型糖尿病 (type 2 diabetes,T2 DM)的相关性。方法　选取安徽省合肥地区汉族 T2 DM患者 2 6 8例 ,正常对照 10 6名 ,用聚合酶链反应扩增片段长度多态性技术进行基因型测定。结果　 (1) PPP1R3基因 3′-非翻译区 5 bp D/I多态性的基因型及等位基因频率在 T2 DM与正常对照组间分布差异无显著性 (P>0 .0 5 )。(2 ) T2 DM或正常对照组中不同基因型间发病年龄、病程、空腹血糖、餐后 2 h血糖、空腹胰岛素、胰岛素敏感指数、体重指数、腰臀围比、收缩压、舒张压差异均无显著性 (P>0 .0 5 )。(3) PPP1R3基因 3′-非翻译区 5 bp D/I多态性频率与日本人群和加拿大人群相近。明显低于 Pima印第安人、瑞典的白人。结论　 PPP1R3基因 3′-非翻译区 5 bp D/I多态性与安徽省合肥地区 2型糖尿病发病无明显关联 ,具有明显的种族差异。     

Few differences in cytokines between patients newly diagnosed with type 1 diabetes and their healthy siblings

The cause of the worldwide increase in type 1 diabetes (T1D) is largely unknown. T cells are thought to play a role in disease progression. In contemporary research over the last decade, age- and gender-specific serum levels as well as changes of Th1 and Th2-related cytokines are not well described. From a population-based register of children diagnosed from 1997 to 2005 this study explores eight different cytokines at time of diagnosis. Only TGF-β and IL-18 showed higher levels in patients compared to siblings in an adjusted model (p < 0.01); whereas the other seven cytokines were not significantly different. IL-1β, IL-18, IL-12, IL-10 and IL-4 were significantly higher among the youngest children and males had significantly lower levels of IL-10 and IL-12 but higher levels of TNF-α. During the nine-year study all of the cytokines increased except TGF-β, which showed a slight decrease over time. The cytokine levels tended to be highest during summer and were most pronounced for IL-1β and TNF-α. In conclusion, serum levels of known β-cell cytotoxic cytokines were indifferent in patients and siblings, while gender, age and season appear to exert some influence on the serum level and need to be explored further. The influence of time on systemic levels cannot be ignored and may reflect decay or environmental impact on the immune system.     

Human parechovirus 1 infections in young children--no association with type 1 diabetes

The epidemiology, transmission and clinical symptoms of human parechoviruses [HPeV, classified earlier as enteroviruses; echovirus 22 (HPeV1) and echovirus 23 (HPeV2)] remain poorly characterized. Enteroviruses and one parechovirus species, the Ljungan virus, have been associated with type 1 diabetes in humans and rodents. The occurrence of human parechovirus 1 (HPeV1) infections in young children and their possible association with type 1 diabetes was evaluated. The prospective birth cohort study comprised 221 Finnish children carrying genetic type 1 diabetes susceptibility and who were observed from birth. Thirty-four children developed multiple diabetes-associated autoantibodies, and 18 children progressed to clinical type 1 diabetes during the follow-up. HPeV1 infections were diagnosed by measuring neutralizing antibodies from the follow-up sera taken every 3-12 months. In addition, viral RNA was analysed by RT-PCR from stool samples taken every month from six of the participants. HPeV1 infections were found to occur early in childhood. The median age of infection was 18 months and 20% of the children had had an infection by the age of 1 year. The number of infections started to increase from the age of 6 months and most children had their first infection by 36 months. Nearly all (99%) mothers were HPeV1 antibody positive. No difference was found in infection frequency between boys and girls, nor between prediabetic, diabetic and control subjects. Most infections (87%) occurred during autumn, winter and spring.     

CD28 CD8 T cells are significantly reduced and correlate with disease duration in juveniles with type 1 diabetes

Type 1 diabetes (T1D) is a chronic disease caused by autoimmune destruction of insulin-producing pancreatic β-cells. T1D is typically diagnosed in children, but information regarding immune cell subsets in juveniles with T1D is scarce. Therefore, we studied various lymphocytic populations found in the peripheral blood of juveniles with T1D compared to age-matched controls (ages 2–17). One population of interest is the CD28⁻ CD8⁺ T cell subset, which are late-differentiated cells also described as suppressors. These cells are altered in a number of disease states and have been shown to be reduced in adults with T1D. We found that the proportion of CD28⁻ cells within the CD8⁺ T cell population is significantly reduced in juvenile type 1 diabetics. Furthermore, this reduction is not correlated with age in T1D juveniles, although a significant negative correlation between proportion CD28⁻ CD8⁺ T cells and age was observed in the healthy controls. Finally, correlation analysis revealed a significant and negative correlation between the proportion of CD28⁻ CD8⁺ T cells and T1D disease duration. These findings show that the CD28⁻ CD8⁺ T cell population is perturbed following onset of disease and may prove to be a valuable marker for monitoring the progression of T1D.